Dune Management and Reptiles: Implications for Habitat Reconstruction and Conservation Strategies

Dune Management and Reptiles: Implications for Habitat Reconstruction and Conservation Strategies.

Thesis submitted in partial fulfillment of the requirements for the degree of “DOCTOR OF PHILOSOPHY”

Boaz Shacham

Submitted to the Senate of Ben-Gurion University of the Negev

January, 2010

Beer-Sheva

Dune Management and Reptiles: Implications for Habitat Reconstruction and Conservation Strategies.

Thesis submitted in partial fulfillment of the requirements for the degree of “DOCTOR OF PHILOSOPHY”

Boaz Shacham

Submitted to the Senate of Ben-Gurion University of the Negev

Approved by the advisor ______29-DEC-2010 Approved by the Dean of the Kreitman School of Advanced Graduate Studies ______

January, 2010

Beer-Sheva

1 Boaz Shacham – PhD dissertation

This work was carried out under the supervision of Dr. Amos Bouskila

In the Department of Life Sciences

Faculty of Natural Sciences

Ben-Gurion University of the Negev

2 Boaz Shacham – PhD dissertation

Acknowledgements Lack of space prevents me including by name all who deserve my thanks for support, advice and help that bring me to this point. I thank the partners in planning, funding and execution of the Nizzanim project. The staff of the Life Sciences Dept. and the Geography and Environmental Development Dept. at Ben Gurion University of the Negev, for preparations, planning, logistics and execution, for scholarships that gave me some peace of mind. The Jewish National Fund (KAKAL), for starting the journey and initializing management actions. Israel Nature & Parks Authority (INPA) rangers, scientists and permit office staff, and for project funding. Shiqmim Field Study School, my beloved de facto second home, for being our base camp during field sessions. The International Arid Land Consortium (IALC), for initial project funding. The Ministry of Science, for project funding. I thank the wonderful people I was honored to work with and learn from. First and foremost, my supervisor Dr. Amos Bouskila, for being guide and mentor to me since we first met more than 25 years past (we both deny it's been that long). Prof. Pua Bar and Dr. Elli Groner, truly the salt and pepper of our Nizzanim expeditions. My fellow M.Sc. & Ph.D. students at Nizzanim, past and present: Adi Ramot, Constantin Grach, Merav Perry, Ahikam Averbouch, Sharon Renan, Tarin Paz, Yehonathan Rubinstein. Our amazing field technicians: Arnon Tsairi, Yael Bogin-Zilka. Our B.Sc. project students, for leaving their mark in my heart as well as the sand: Arnon Yohanan, Shlomi Aharon, Noa Angel, Eyal Ben David, Na'ama Brener, Irit Messika, Hadas Ast, Ilana Ben David. To our "reservists" who volunteered to supplement or head reptile teams: Amir Arnon, Karmit Arbel, Tamar Amit, Itai Renan, Gal Vine, Eran Banker. My dear friends and partners guiding in the dunes, Avishay Shlomo and Dr. Oded Cohen. Many dozens of students who helped collect data within ecology camps of Life Sciences Dept., Geography & Environmental Development Dept. and Arava Institute for Environmental Studies. My colleagues at the Life Sciences Dept., for hours of fruitful corridor chats, prep and work as teaching assistants in labs and field trips, and forgiveness for my lengthy seminar lectures. The amazing Life Sciences Dept. secretariat, always helpful and smiling even via email: Hanna Hatav, Iris Reuven, Dalit Dahan, Anat Ben Haroush. At INPA, Dr. Yariv Malihi, Dr. Yehoshua Shkedy, Ronen Shavit, Koby Soffer, Itamar Wollis, Shai Cohen. Yair Farjun, man and legend, for nurturing my sand obsession. Elimor Fried, for the continued cooperation of Shiqmim Field School. And my M.Sc. supervisor Prof. Yehudah L. Werner, for supplying (past and present) tools for my evolution as a scientist. And last but not least, I warmly thank my dear family, for continuously accepting me and my accompanying critters. To my mother Nurit for instilling my love for nature and animals from day one, my brothers Lee Or and Uri for forgiving my total lack of interest in soccer, to my beloved Sharon for tolerating weird work hours and dunes wandering into our home, and to our lovely daughter Tamar for giving us a reason to smile every morning. I am lucky to have all of them, including Tamar, as partners in my "hunting expeditions" from time to time.

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Dedication I dedicate this work in memory of my late father, Yoram Shacham (Weinraub) ZL, whom I never had the privilege to meet, but as years pass it becomes obvious that an affinity to science and love for nature binds us far and beyond our hereditary connection. And also, to my beloved grandparents, Lena and Moshe Biegeleisen ZL and Donia and Heini Weinraub ZL, and to Moya Shalgi, may they rest in peace, who did not live to see the upcoming piece of familial satisfaction: the kid is about to finish his doctoral degree.

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Table of Contents

ABSTRACT …………………………………………………………………………………….. 4 Introduction ……………………………………………………………………………………... 9 Coastal Dune Ecosystems ………………………………………………………...... 9 Coastal Sand Dunes in Israel ……………………………………………………...... 12 Choosing Nizzanim Sands as a Case Study ………………………………………………. 15 The Nizzanim Project ………………………………………………………………….…. 19 Study Questions, Hypotheses & Predictions….………………………………………………… 23 The Research Questions ……………………………………………………...... 23 Products of This Study ……………………………………………………………………. 23 Hypothesis & Predictions ………………………………………………………………… 24 Methodology ……………………………………………………………………………………. 26 The Study Site ………………………………………………………………………..…… 26 Experimental Design ……………………………………………………...... 29 Methods for Sampling the Reptiles ………………………………………………………. 35 Data Analysis Techniques ……………………………………………………...... 42 Results I: Reptile Assemblages at Nizzanim Sands …………………………………………….. 45 Species Assemblages on Various Plot Types ……………………………………….…….. 45 Effects of Vegetation Cover on Reptile Species Assemblages ……………………………. 53 Seasonal Effects on Reptile Activity and Abundance …………………………………….. 55 Patterns Seen in Diurnal Lizard Observations …………………………………...... 59 Results II: Response of Reptiles to Dune Management ………………………………………… 62 Changes in Reptile Assemblages Following Management Actions …………………….… 62 Trajectory of Management Effects Through Time ………………………………………... 70 Effects of Management on Lizard Body Condition ……………………………………… 77 Response of Acanthodactylus to Dune Management ………………………………..…… 85 Discussion and Conclusions ……………………………………………………………………. 92 Reptile Assemblages at Nizzanim Sands ………………………………………………… 92 Reptile Assemblage Response to Manipulation at Nizzanim Sands …………………….. 96 Implications for Management and Monitoring ………………………………...... 103 Potential Obstacles: How does the Project Measure Up? ……………………...... 111 Summary of Conclusions from Nizzanim Sands …………………………………………. 113 Summary of Recommendations for Monitoring Sand Dune Reptiles ……………………. 114 New Study Questions Arising from this Project ……………………………………..…… 115 References ………………………………………………………………………………………. 117 Appendix I: Restoration Ecology – Definitions, Strategies, Potential Problems, Design ……… 128 Definition of Basic Terms …………………………………………………………….….. 128 Conceptual Framework ……………………………………………………...... 129

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Preliminary Assessment ……………………………………………………...... 130 Thematic Questions ……………………………………………………...... 131 Potential Difficulties Interpreting Outcomes of Restoration ……………………………... 131 The Need for Strategic Planning in Restoration ………………………………………..… 131 Appendix II: Herpetofaunal Checklist of Nizzanim Sands and Environs ……………………… 133

Figures and Tables

Figure 1: Active dune……………………………………………………………………………………... 27 Figure 2: Semistable dune………………………………………………………………………………… 28 Figure 3: Stabilized dune………………………………………………………………………………….. 29 Table 1: List of the study plots presented in this work……………………………………………………. 30 Figure 4: General map of Nizzanim sands study site……………………………………………………... 31 Figure 5: Bulldozer at work.………..…………………………………………...... 33 Figure 6: Plot marking.………………………….…………………………...... 33 Figure 7: Debris from removal. ……………………………………………………...... 34 Figure 8: Aerial photo of manipulated dunes. ……………………………………………………...... 34 Table 2: Characteristics of data obtained by each sampling method……………………………………... 37 Figure 9: Spatial scheme of sampling methods.………….…………………………………………...... 38 Figure 10a: Schematic side view of bucket pitfall trap.….………………………………………………. 39 Figure 10b: Schematic top view of bucket pitfall trap.….………………………………………………... 39 Figure 11: Pitfall configuration and numbering.………….…………………………………………...... 40 Figure 12: Covered pitfall.………………………………….…………………...... 40 Figure 13: Pitfall exposure.………………………………….…………………...... 41 Figure 14: Track transect.……….……………………………………………...... 41 Table 3: Summary of species found.………………….…………………………………...... 46 Figure 15: Proportional incidence of common species.…….…………………………………………….. 47 Table 4: Average observations and species richness.……….…………………………………………….. 49 Table 5: Average species richness pooled for all methods.……….………………………………………. 50 Figure 16: Average species richness indices.……….……………………………………………...... 51 Figure 17: Average proportion of desert specialist species.………….…………………………………… 52 Figure 18: Multivariate analysis of un-manipulated plots.………….………………………………….…. 54 Figure 19: Spring season data.……….……………………………………………...... 57 Figure 20: Summer season data…………………………………………………………………………… 57 Figure 21: Autumn season data.…………….………………………………………...... 58 Table 6: Average numbers of Acanthodactylus lizards.……….………………………………………….. 59 Figure 22: Average numbers of Acanthodactylus lizards.………….…………………………………….. 59 Table 7: Total numbers of Acanthodactylus lizards observed.………….………………………………… 60 Figure 23: Incidence/abundance phase plane of Acanthodactylus species observed……………………... 61

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Figure 24: Average species richness indices at the different plot types…………………………………... 65 Figure 25: Proportion of desert specialist species at the different plot types……………………………... 66 Table 8: Average species richness indices at the different plot types…………………………………….. 66 Table 9: Total species richness significance levels.…………………….……………………………….... 67 Table 10: Generalist species richness significance levels.……….……………………………………….. 67 Table 11: Desert specialist species richness significance levels………………………………………….. 67 Table 12: Desert specialist proportion significance levels………………………………………………... 68 Figure 26: Multivariate analysis of all plot types pre- and post-manipulation……………………………. 69 Figure 27: Multivariate analysis of 2004 sessions.………….…………………………………………..... 71 Figure 28: Multivariate analysis of 2005 sessions.………….…………………………………………..... 72 Figure 29: Multivariate analysis of 2006 sessions.……………………………………………………...... 73 Figure 30: Multivariate analysis of 2007 sessions.………….………………………………………….... 74 Figure 31: Multivariate analysis of 2008 sessions…..………………………………………………….... 75 Figure 32: Time-series analysis of assemblages' response……………………………………………….. 76 Figure 33: Formula used for calculating lizard ratio body index (BI)……………………………………. 77 Figure 34: Tail injury rate in S. sepsoides………………………………………………………………… 78 Table 13: Tail injury rate in S. sepsoides…………………………………………………………………. 79 Table 14: Tail injury in S. sepsoides statistical significance……………………………………………… 79 Figure 35: Body condition index of S. sepsoides across plot types………………………………………. 80 Table 15: Body condition index of S. sepsoides statistical significance………………………………….. 80 Figure 36: Examples of S. sepsoides specimens.……………………………………………………...... 81 Figure 37: Tail injury rate in S. sthenodactylus…………………………………………………………… 82 Table 16: Tail injury rate in S. sthenodactylus……….……………………………………………...... 83 Table 17: Tail injury in S. sthenodactylus statistical significance………………………………………… 83 Figure 38: Body condition index of S. sthenodactylus across plot types…………………………………. 84 Table 18: Body condition index of S. sthenodactylus statistical significance……………………………. 84 Figure 39: Example of S. sthenodactylus specimen.…………………………………………………….... 85 Table 19: Total numbers of Acanthodactylus lizards observed…………………………………………… 87 Figure 40: Average numbers of Acanthodactylus lizards observed………………………………………. 87 Table 20: Average numbers of Acanthodactylus lizards observed……………………………………….. 88 Table 21: A. scutellatus significance levels.……………………………………………………...... 88 Table 22: A. schreiberi significance levels.……………………………………………………...... 88 Figure 41: Incidence/abundance phase plane of Acanthodactylus species observed……………………... 90 Figure 42: Exemplars of A. scutellatus……..………………………………………………...... 91 Figure 43: Exemplars of A. schreiberi……………………………………………………...... 91 Figure 44: Hypothesized relationship of species diversity with dune stabilization………………………. 93 Figure 45: Hypothesized trade-off between predation and competition………………………………….. 102 Table 23: Reptile species checklist of Nizzanim sands and environs…………………………………….. 133 Table 24: Amphibian species checklist of Nizzanim sands and environs………………………………… 134

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ABSTRACT

The Mediterranean coastal sand dunes of Israel comprise a locally and globally unique ecosystem, the arid aeolian soil enables numerous Saharan taxa to penetrate northward, in spite of the temperate climate. Many endemic taxa, mainly of plants and invertebrates, have evolved locally in the habitats along the coast. Over the last six decades, Israel’s coastal sands have been heavily developed, reducing the intact habitats from 462 km2 at the start of the 20th century to about 250 km2 presently, of these less than half are statutory-protected. Of the many threats looming over the survival of these sands, probably the most serious is dune stabilization. The major factor causing dune stabilization has been shown to be the cessation of traditional “Mawasi” farming and goat grazing since the 1950’s, which in the past maintained unstabilized dunes. Analyses of aerial photos of Nizzanim dunes, in the southern coastal plain, showed drastic changes over the last 40 years in vegetation cover of the study area, with 82% increase in stabilized dunes and 37% decrease in active (unstabilized) dunes. Extrapolation of current vegetation change trends predicts that Nizzanim sands will become stabilized dunes (>60% cover) within 30 years, unless active management is applied. Sand stabilization causes local extinction of desert specialist species by generalist species. Partial vegetation removal has experimentally succeeded in rehabilitating psammophilic rodent communities in central coastal Israel (Park Ha-Sharon), and is currently being tested as a practical solution to stabilization at Nizzanim.

This dissertation presents the results of my study regarding the effects of partial vegetation removal from stabilized dunes on reptiles in Nizzanim sands, Israel. I worked within a long-term multi-disciplinary project at Nizzanim (other teams study invertebrates, rodents and plants), aimed mainly to assess management tools for sustaining unique coastal sands biota. The main goals of my study were threefold: [1] to describe the reptile assemblages present on naturally occurring dune types; [2] to describe the effects of partial vegetation removal on reptile assemblages; and [3] to draw operational and conceptual conclusions and recommendations for future monitoring and study of the reptiles in the Nizzanim project and elsewhere. The latter goal included comparison among several treatment regimes for manipulation of dune vegetation,

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identification of effective indicator species among the reptiles, and integration and analysis of several sampling methods I had used for data collection.

The data presented here were collected from May 2004 until September 2008 (inclusive), in field sessions conducted at least during two different seasons per year. My analysis includes twenty-two (22) study plots (4000 m2 each), of three different natural dune types and three different manipulated dune types, and for each of these six categories I sampled at least three replicates (plots). Experimental design follows the M- BARCI model, comprising multiple (M) replicates of before (B) and after (A) manipulation sampling, conducted at reference (R), control (C) and intervention (I) plots. Natural, unmanipulated plots (reference & control) included three categories: Active dunes (= unstabilized, <10% perennial vegetation cover, n=3); semistable dunes (~25% cover, n=6); and stabilized dunes (>40% cover, n=3). Manipulated plots (intervention) included three categories (treatment regimes): MCA, semistable dunes manipulated to active dune vegetation levels (n=4); MDA, stabilized dunes manipulated to active dune vegetation levels (n=3); and MDB, stabilized dunes manipulated to semistable dune vegetation levels (n=3). Manipulation was carried out by mechanical means in March 2005 on seven study plots (all MDA & MDB plots, one MCA plot) and in November 2005 (remaining three MCA plots), after baseline "before" data were collected from all plots. Within each session, each plot was sampled for two consecutive nights and days, by small teams (2-3 people), with each team sampling a maximum of 4 plots per date. Samplers and equipment were transported by four-wheel drive vehicles, to maximize efficiency, taking care to drive only on previously established tracks and roads.

Reptiles were sampled using several methods: [1] Pitfall traps, 10 buckets (plastic, 10 liter volume) per plot buried flush with ground level, opened around sunset and examined in early morning, supplemented by 30 small cups (plastic, 500 ml) per plot used for invertebrate sampling (reptiles inadvertently trapped by the invertebrate study team were transferred to the reptile team for processing and release); [2] Track transects, erased around sunset and examined at dawn, 2 transects (90 m) per plot; [3] Diurnal lizard activity transects, conducted mid-morning during peak lizard activity – visual observations were recorded while walking four 90 m transects per plot; [4] All incidental ("occasional") reptiles observed were also recorded; [5] Captured reptiles were

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specifically identified, weighed, measured, sexed, marked for individual identification and released.

Univariate (ANOVA, Chi2 Test, Fisher's Exact Test, Student's t-Test) and multivariate (RDA = Redundancy Analysis, PCA = Principal Component Analysis, PCR = Principal Response Curve) statistical methods were used for the analysis of my results. Data from the different sampling methods were analyzed separately, and then re-analyzed as one combined data set (after transformation and standardization across the different methods).

The data from the unmanipulated (reference & control) plots show that [1] active dunes are dominated by three desert specialist lizard species (Acanthodactylus scutellatus, Sphenops sepsoides and Stenodactylus sthenodactylus), which are limited in the Mediterranean climatic region along the coast to sand habitats; [2] in semistable dunes two additional lizards (A. schreiberi and Chalcides ocellatus), both of Mediterranean distribution, are added to the assemblage; and [3] in stabilized dunes additional Mediterranean species are added to the fauna, mainly two lizards (Mabuya vittata and Ablepharus rueppellii) while one desert specialist (A. scutellatus) effectively disappears. The diurnal A. scutellatus characterizes active dunes, while A. schreiberi characterizes stabilized dunes, both sharing to some extent the semistable dunes. Species richness was highest in the stabilized plots, but this is caused solely by the increase in generalist (Mediterranean) species found as dune stabilization increases. Assemblages in the different plot types were well differentiated in PCA analyses. The most significant environmental effect associated with variation among the assemblages was total perennial vegetation cover, which showed high autocorrelation with other environmental variables tested (proportional cover of different plant life-forms; organic matter content in soil).

The data from the manipulated plots showed, for some of the species, similar trends to those seen in the naturally (unmanipulated) semistable or active dunes. For instance, occurrence of S. sepsoides at treated plots initially declined to levels close to those at untreated plots. However, species composition in most manipulated dunes is more similar to pre-manipulation composition, and is still far from the composition of naturally active or even semistable dunes. There was substantial overlap of assemblages of all

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manipulation regimes with their control (pre-manipulation state) plots as well as the reference (target state) plots in the PCA analyses. Trajectories of MDA and MDB regimes initially shifted towards targeted states, but later seemed to regress back to pre- manipulation states, in the PCR analysis. MCA regime showed a more promising trajectory toward targeted state in the PCR analysis, but none of the manipulation regimes fully reached the projected targets.

The main factor preventing the MDA and MDB plots from reaching target assemblages in the period of time covered in my study was the failure of A. scutellatus to colonize these plots. This is probably due to physical obstacles between source populations of this species and the MDA, MDB plots. I attempted to experimentally relocate lizards of this species (N=49) from source dunes into some of the manipulated dunes in late October 2007, but they failed to colonize the plots. I suggest that relocation be attempted on a larger scale, with more rigorous planning and, optimally, employing acclimation techniques for the relocated animals.

Analyses of tail injury rates and body condition indices of the most commonly trapped lizards, S. sepsoides and S. sthenodactylus, reveal trends of decreased tail loss parallel with deterioration in body condition with increased dune stabilization in the unmanipulated plots; these trends are mirrored in all manipulation regimes – both tail loss rate and body condition increase following vegetation removal. These results hint at a trade-off between inverse gradients in predation pressure and resource competition along the dune stabilization gradient. I suggest that these phenomena be studied more in depth, in an attempt to find if these trends become significant effects when larger populations are sampled. A byproduct of such study will be a better understanding of the life histories of these species, and a potential bio-indicator for management effects based on physical responses.

All data collected to date point to the Acanthodactylus lizards as being the best, most cost-efficient bio-indicators for the reptiles at Nizzanim and perhaps elsewhere, but this should be assessed on a case-by-case level. I suggest broadening the scope of data collected on these lizards by adding daytime-hours pitfall trapping, using extant plots and

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traps, thus gaining better insights on lizard demographics, life history, and responses to the manipulation regimes.

While it is still too early to declare success or failure of rehabilitation of psammophilic species assemblages on stabilized dunes following partial vegetation removal, the results seem encouraging. Future trajectories of the plots depend on dynamic decision making and continued monitoring of all taxa involved. Successional processes seem to have begun on some of the manipulated plots, ushering the need for repeated vegetation removal. Project managers are currently exploring possibilities for alternate vegetation management techniques, e.g. camel grazing.

The methodological conclusions from my work are no less important than the specific conclusions regarding reptile assemblages and manipulation effects at Nizzanim. In order to see the broadest picture possible, it is critical to employ multiple sampling methods for the reptiles. No single method covers the entire repertoire of species present in the coastal sands, and no single species covers the full picture of management effects on the assemblages. Some of the rare species are important conservation-wise, and cannot be ignored, for instance the diurnal lizard Varanus griseus, which had been observed in only 1% of all samples analyzed in my study. Pitfalls usually fail to capture snakes, but these commonly appear on the track transects. Tracks transects measure activity levels, but fail to produce the morphological and demographical data available from pitfall trapping. Both pitfalls and track transects in my project were aimed only at nocturnal species, hence the importance of the diurnal lizard transects. Thus, the various methods I used to obtain data were complementary, each contributing to understanding the assemblages and following the trajectories of the manipulated plots through time. The method I used for combining the data sets from all methods into one common matrix for multivariate analysis is very helpful for integrating all the data, but one must not ignore the advantages of also analyzing each method separately, lest one misses some of the available resolution obtained through much effort in the field.

The reptiles in this project must be monitored in the years ahead; I believe that the methodology and the study questions will evolve with the evolution of the project and

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together with the other taxa studied supply answers for conservation policy of the coastal dunes at Nizzanim and elsewhere.

KEY WORDS: Coastal sands; reptiles; manipulation; management; restoration; perennial vegetation removal; stabilization; active dunes; semistable dunes; stabilized dunes; desert specialist species; generalist species; psammophiles; Mediterranean.

Introduction

Coastal Dune Ecosystems

Coastal sand dunes are natural habitats with extremely high conservation values, because the dynamic nature of the dunes creates a landscape with highly variable topography and aspect, and with variable edaphic factors that together provide suitable habitats for a wide variety of specialist flora and fauna. To achieve this high degree of heterogeneity, coastal dunes must be maintained in a dynamic, shifting state. These aeolian, shifting features of active dunes create ever-present habitats for early successional vegetation, which, through time, become more established and tend to be more densely vegetated (Kutiel et al., 1979/80; Kutiel, 19982).

Despite their high conservation value, coastal dunes have been subjected to considerable human impacts, including sand stabilization using non-native, invasive plants such as Pinus mugo in Denmark, P. pinea in Spain and South-Africa, various ice- plants (Mesembryanthemum) in Portugal, Ammophila breviligulata and Calamovilfa longifolia over much of the world, and Acacia saligna in Israel, Turkey and Cyprus (http://www.michigan.gov/dnr/0,1607,7-153-10370_12146_12209-61330--,00.html; www.coastalguide.org). These stabilizing plants modify the nature of the vegetation and fauna, decrease landscape heterogeneity and biodiversity, change the geomorphologic characteristics of sand dunes, and even massively reduce the area of dune landscapes (Slobodchikoff & Doyen, 1977; Nordstrom & Lotstein, 1989; Kutiel & Sharon, 1996; Kutiel, 2001; Kutiel et al., 2002; Tsoar & Blumberg, 2002).

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According to a study by the World Resources Institute, 70% of European coastlines are highly threatened (van der Meulen & Salman, 1996) and only 45% of the coastline in Western Europe remains intact, in its natural state. In the Mediterranean a mere 25% remains intact (www.coastalguide.org/eco/dunes.html). The value of coastal dunes and the importance of their mobility are increasingly being recognized, worldwide, and this has led to many efforts to initiate programs of ‘dynamic conservation and restoration management’ (Nordstrom & Lotstein, 1989). The restoration capacity of dunes appears to be considerable due to their dynamic nature. Removal of forests and other alien stabilizing vegetation and re-establishment of dynamic, shifting dune formations are amongst the restoration measures being undertaken (www.coastalguide.org/eco/dunes.html).

Two modes of restoration are being undertaken. The first, which emphasizes the reintroduction and establishment of native species, has been criticized for drastically altering and decreasing the gene pool of native species. The second, involving management practices that reduce perennial vegetation cover, opens the canopy through grazing (Kooijman & van der Meulen, 1996; Hester et al., 1994). Grazing by domestic livestock and native herbivores such as rabbits has had major impacts on dune vegetation throughout Europe and has been instrumental in forming the present dune landscape (McManus, 1988). This method facilitates the natural colonization of sand-dwelling species with a subsequent increase in biodiversity. In several dune areas, biodiversity management practices involve more than a single method (Doing, 1997; Doody, 2000).

Coastal dune systems are susceptible to invasion due to their open, non-competitive nature and frequent disturbances that stimulate alien-pioneer species establishment (Baker, 1986; Hobbs & Huenneke, 1992; D’Antonio, 1993; Holmes & Cowling, 1997; Sher & Hyatt, 1999; Cohen et al., 2003). Both the establishment of alien-pioneer species and loss of natural habitat reduce diversity (Rosenzweig, 2001). In most cases, invasive plants, which have been planted to stabilize shifting coastal dunes, are the main colonizing species on the coastal dunes. Two main methods are used to manage alien, invasive plants: (1) hand removal of the plants or, in case of trees, felling with chain saw and chipping the timber with or without removal of the woodchips; and (2) herbicide

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control. These actions are directed at restoring native plant biodiversity and at re- establishing shifting dune ecosystems. Neither of these restoration efforts, however, is directed towards the fauna of shifting dunes.

Shrubs exert both direct and indirect effects on the entire community. Many species of fauna benefit directly from shrubs because of the increased availability of food for herbivores and detritivores; cooler, more humid microhabitat; and shelter from large predators that they provide (Crawford, 1981). Shrubs also change the community structure by serving as ecosystem engineers (sensu Jones et al., 1994). By stabilizing the sand, shrubs favor generalist and opportunist species over their specific psammophile competitors (Wasserberg, 1997; Hauser & Irwin, 2003; Wasserberg et al., 2005). By removing shrubs, a horizontal change in species composition within any given trophic level is expected. In addition, a vertical “trophic cascade” is hypothesized, caused by top- down forces altering the population dynamics across trophic levels. Four major trophic levels exist in arid habitats (Ayal, 2000): large predators (mammals and birds), insectivores (rodents, reptiles, arachnids, centipedes and large insects), primary consumers (herbivores and detritivores) and primary producers (shrubs, annuals and cyanobacteria). The greatest beneficiaries of shrub refuges are the insectivores, which are able to hide and remain active under the shrubs. The shrubs reduce the predation efficiency of large predators (Groner & Ayal, 2001). Shrub removal is therefore expected to increase the activity of insectivores with a consequent reduction in primary consumer abundance, to change the structure of the local food-web horizontally by favoring psammophile species and those less dependent on shrubs and to change the food-web vertically by altering the ratio of insectivore abundance to that of primary consumers.

With an increase in sand mobility, species composition shifts from generalists to specialist psammophiles among several taxa sensitive to soil type. The psammophile primary consumers, although restricted to vegetation found on shifting dunes, are more dependent on abiotic factors than on the floral characteristics of the habitat. This is true for rodents (Wasserberg, 1997), which are granivores, and tenebrionids (Ayal & Merkl, 1994), which are detritivores. Predators are generally more dependent on habitat structure than on its floral characteristics; among these are reptiles (Bouskila & Amitai, 2001;

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Bouskila & Dickman, unpublished MS; Hawlena & Bouskila, 2006) and stiletto flies (Insecta: Diptera: Therevidae) (Irwin 2001; Hauser & Irwin, 2003).

Many primary consumers in stabilized dunes feed on roots of stabilizing vegetation. Others feed on detritus, particularly on dead vegetation that forms litter, which is often abundant under shrubs. In contrast, the major consumers in shifting dunes are confined to feeding on detritus trapped in layers beneath the shifting sand. This provides a distinctly different habitat. Insectivorous arthropods that feed mainly on primary consumers have dissimilar prey search strategies in these two distinct sets of environments. Such seems to be the case with stiletto flies, whose larvae are voracious predators of underground insect larvae. Within various genera of these predaceous flies, the more widely distributed, generalist species are those associated with stable sand environments while those that are restricted in their distribution and are more specialized in their prey selection are closely associated with shifting dune systems (Hauser & Irwin, 2003).

Of all the arid habitat traits that have been investigated, the structure and complexity of the vegetation is particularly important in determining small mammal, reptilian and arthropod species diversity (Ayal & Merkl, 1994; Groner & Ayal, 2001; Bouskila & Dickman, unpublished MS). “The habitat-diversity hypothesis” (proposed by Rosenzweig, 1995) suggests that regions containing heterogeneous habitats support diverse faunas. In Western Australia, for example, removal of the spinifex shrub microhabitat reduced species richness of small mammals and reptiles by 50% and 30%, respectively (C. Dickman, pers. comm.). The study of temporal and spatial patterns of vegetation in a habitat is thus crucial for understanding the habitat’s faunal diversity and composition.

Coastal Sand Dunes in Israel

The coastal sands of Israel are a locally and globally unique ecosystem, comprising a rare rendezvous of Aeolian desert soil, from the Nile delta, with a humid-temperate Mediterranean climate. Dozens of desert floral and faunal species, mostly of Saharan or Saharo-Arabian distribution, penetrate northwards along this coastal sandy "corridor" in

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spite of the Mediterranean climate (Werner, 1987; 1988). Israel's Mediterranean coastal plain is 190 km long, its width varying from 1 km in the north and 7 km in the south. It includes thousand-year-old sand dunes in various degrees of stabilization. Most of the coastal plain is extensively inhabited by humans (about 60% of the population of Israel), heavily developed, and widely polluted. According to the Israel Nature and Parks Authority data, a mere 17% of the Israeli coastal dunes remain ecologically intact, and less than 5% of that area is designated protected open space (Kutiel, Peled & Geffen, 2000).

The unique abiotic factors and penetration of desert organisms in the coastal strip also make it an important center of speciation for sand-dwelling flora, small mammals, reptiles and invertebrates, giving rise to various endemic taxa. In the past, the coastal dunes of Israel offered a rich variety of vegetation associations, with high plant species richness comprised of numerous endemics (Naveh & Kutiel, 1990). Even today, 31 endemic plant species (most of them annuals) can be found in the sandy habitats of the coastal plain, constituting 20% of all endemic plant species in Israel – the highest rate of endemism of any given habitat (Shmida, 1982). The only mammal species endemic to Israel, the Buxton’s jird (Meriones sacramenti), and an endemic subspecies of Anderson’s gerbil (Gerbillus andersoni allenbyi, previously referred to as G. allenbyi) are found in this region as well as in the north-western Negev sands (Zahavi & Wahrman, 1957; Yom-Tov & Mendelssohn, 1988; Wasserberg, 1997; Shalmon, 2002). The sand- dwelling lizard, Acanthodactylus schreiberi, which, according to IUCN definitions (Bouskila, 2002), is critically endangered, still exists in the sands of the coastal plain, but its habitat is rapidly disappearing. Stiletto flies and their relatives are also endemic to this area, for example Stenomphrale teutandhamen (Diptera: Scenopinidae), found in Nizzanim dunes and south of them, and the stiletto flies, Neotherevella citrina and Rueppellia throacica, both confined to the coastal strip of North Africa and Israel. Several new insect species have been described from Nizzanim, including leaf beetles (Lopatin & Chikatunov, 1999).

Over the last six decades, Israel's coastal dunes are undergoing processes causing irreversible changes of their habitats and ecosystem. Due to massive coastal development,

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total sand dune area has shrunk from 462 km^2 at the turn of the 20th century to circa 250 km^2 in the present decade, of these barely 50% are statutorily designated as protected areas (nature reserves or national parks) (Ahirun-Frumkin et al., 2003; Amir & Shapira, 2005). Today, we are witnessing landscape and ecological magnitude changes in Israel’s coastal dunes. Vast stretches of ecologically viable shifting coastal dunes have been increasingly subjected to shrub and dwarf-shrub encroachment. Aerial photographs taken in 1944 depict active barchans and transverse dunes covering more than 5% of the area. During the past 50 years, woody vegetation has encroached and now covers 80% of the dune crests. This has resulted in gradual but substantial dune stabilization with a consequent change in dune crest morphology from transverse to parabolic (Kutiel & Sharon, 1996; Kutiel, Peled & Geffen, 2000; Kutiel et al., 2002; Tsoar & Blumberg, 2002).

Since their formation some thousand years ago, the coastal dunes have been impacted by humans. The Jakotin map (1818), for example, describes the coastal dunes as unvegetated and active in character. This shifting nature of the dunes was retained for many years by removing significant amounts of vegetation, which was extensively utilized by people (e.g., nomadic Bedouins) inhabiting the coastal region long ago. The dominant native shrubs, desert broom (Retama raetam) and the monosperm wormwood (Artemisia monosperma), unpalatable to sheep and goats due to high tannin content (Perevolotsky, pers. com.), were harvested for firewood by Bedouins. Additionally, herds of sheep and goats trampled the physical and biogenic crust of the upper sand layer, helping to prevent sand stabilization (Kutiel, 19981; Kutiel et al., 1999; Kutiel, Zhevelev & Eden, 2000). Apart from their impact on sand mobility, sand crusts directly impact habitat suitability to animals (Zaady & Bouskila, 2002). The destruction of the crusts led to a landscape dominated by shifting and semistable dunes because the vegetation responsible for dune stabilization was constantly being suppressed. Additional human activity included traditional agriculture practices in the interdunes ("Mawasi" farming), still practiced today in parts of the Gaza strip and north-western coastal Sinai. The aforementioned processes maintained the dunes almost devoid of vegetation until the second half of the 20th century, at which time grazing, cutting and "Mawasi" farming were all dramatically curtailed. Since 1950, the dunes have been under a continuous

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process of stabilization, linked by various studies to these changes in land use (Kutiel & Sharon, 1996; Tsoar & Blumberg, 2002; Kutiel et al., 2002; Levin et al., 2003; Levin & Ben-Dor, 2004). The geomorphological and ecological significance of this stabilization process is expressed in changes in landscape features (Tsoar & Blumberg, 2002), a decrease in landscape heterogeneity and biodiversity (Kutiel et al., 2002), and changes, including a reduction in the sand-dwelling (psammophile) component, and in the flora and fauna composition of the ecosystem (Kutiel, Peled & Geffen, 2000; Kutiel, 2001; Kutiel et al., 2002). Remarkably, however, a few of the dunes retain relatively little plant cover and considerable mobility.

Other prominent processes which have been central in decreasing and degrading Israel's coastal sands include: development and building, roads and infrastructure, habitat fragmentation, sand quarrying (legally and illegally), biologically invasive plants (e.g. the Australian Acacia saligna and the North American Heterotheca subaxillaris), increase in populations of "explosive" animal species (e.g. hooded crow Corvus corone and golden jackal Canis aureus), over-exploitation of groundwater from the coastal aquifer, illegal waste dumping and increased all-terrain vehicle use.

As sands become more stabilized, there is gradual replacement of the psammophile flora and fauna species by generalist (Mediterranean) species, sometimes to the point of local extinction of the psammophiles. In the absence of active management, it is projected that the entire landscape unit of Ashdod-Nizzanim dunes shall be transformed into stabilized sands with at least 60% perennial vegetation cover by the year 2036 (Kutiel et al., 2004).

Choosing Nizzanim Sands as a Case Study

With the ultimate aim of conserving the coastal dune landscape, including its unique biota, the agencies in charge of natural resources in Israel (INPA – Israel Nature & Parks Authority; JNF – Jewish National Fund = Keren Kayemet Le'Israel) began to seek active management solutions. This management is intended to stop sand stabilization in some instances and in others to rehabilitate or reconstruct shifting sands where these have been

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stabilized. When using the term "rehabilitation", the aim is to bring the ecosystem to a similar but not identical state to the "original" (historic) state before degradation (Society for Ecological Restoration International Science & Policy Working Group, 2004; see definitions in Appendix I). In the case of Nizzanim sands – the degradation is due to sand stabilization and the processes that led to it. When using the term "restoration", the aim is to perfectly restore the "original", pre-degraded state (see definitions in Appendix I). Development of management tools and policy for this ecosystem requires experimental study of how management actions affect the landscape, flora and fauna. On the landscape level, the management must involve geomorphologic study, to test the physical aspects of management effects. Regarding the biotic components of the ecosystem, as the literature points out, there must be a strong connection between management actions and theoretical ecological principles (e.g.: Lake, 2001; Palmer et al., 1997; Scott et al., 2001). Relevant research questions regarding management techniques in Israel's coastal dunes which intertwine with ecological theory include (adapted from Palmer et al., 1997): 1. What are the endpoints ("goals") of the rehabilitation/reconstruction actions? 2. Are species composition and biodiversity appropriate indices for assessing management effects? 3. Can theoretical empirical study of succession and dispersal processes contribute to understanding the management effects?

4. Is habitat rehabilitation an appropriate and satisfactory approach for achieving all the goals of the management?

Several studies of Ashdod-Nizzanim sand dunes have been conducted in recent years and act as preliminary data for my study. The main body of these works deals with geomorphology (Tsoar & Blumberg, 2002; Levin et al., 2004; Levin & Ben-Dor, 2004) and with temporal changes in vegetation cover (Levin et al., 2003; Kutiel et al., 2004), linking anthropogenic factors to dune stabilization. Additional work conducted in these dunes found evidence of centrifugal social structure in rodent communities, with competitive exclusion between two species of Gerbillus common to this area: the sand specialist G. pyramidum excludes the smaller G. andersoni allenbyi from the shifting dunes to the semistable and stabilized dunes (Wasserberg, 1997). More recently, the

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effects of perennial vegetation cover and the invasive Acacia saligna on rodent assemblages in Nizzanim dunes has been reported (Anglister et al., 2005).

Data on landscape, flora and fauna in Nizzanim sands have been collected and published by various authors over the last two decades, but none of these address applicable management questions. These works include reports aimed at local (Rudikh & Farjun, 1999; Amir & Shapira, 2005) and national (Ahirun-Frumkin et al., 2003; Perelberg et al., 2005) planning of coastal sands conservation strategies. Other works include data on reptile and rodent inventories of Nizzanim dunes collected during 2001 for an INPA survey (Dolev et al., 2002 ) and during 1997-2009 while guiding activities of Shiqmim Field Study School of the SPNI (Society for the Protection of Nature in Israel) by B. Shacham (unpublished data) (see species checklist, Appendix II). My M.Sc. project on polymorphism of the snake Psammophis schokari in the coastal sands revealed morphological and demographical differences, linked to perennial vegetation cover, between the populations at Nizzanim sands when compared to more stabilized Palmahim sands (Shacham, 2004). Nevertheless, the data collected in these previous studies does not give answers regarding the possible responses of reptile assemblages in Nizzanim sands to future stabilization of the sands or active management in this ecosystem.

There are many examples in the scientific literature of studies conducted on management of natural habitats with attention given to the ecological mechanisms driving the processes. Litt et al., (2001) compared several management techniques (fire, clear cutting, pesticides) to rehabilitate sandhills dominated by longleaf pine (Pinus palustris) in Florida. They found that habitat modification brought about changes in reptile assemblages already in the short-term (within 2-3 years of management actions), towards species composition that resembled the historical pristine habitat. This ecosystem had historically been subjected to periodical fire, which had been suppressed by man during recent decades, and the goal of the management was to imitate thinning of trees previously caused by fires (Litt et al., 2001). A study conducted in Lake Prespa National Park (Greece) found differences in spatial distribution and micro-habitat use between lizard species compared to snake species (Ioannidis & Bousbouras, 1997), something that I must take into account in my work as well. Work conducted in a pastoral landscape in

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New South Wales, Australia, demonstrated the challenges of managing multiple species at multiple scales, with different reptile species responding differently to the various environmental factors at various resolutions (Fischer, Lindenmayer & Cowling, 2004), such phenomena may occur also in my study.

Establishing a data set covering species inventories and distribution patterns relevant for conservation decisions and policy is expected to be a long and challenging process. A study conducted in Australia has shown that, since species accumulation curves are dependent on both reptile abundance as well as on search effort (number of sampling days and quantity of traps), large amounts of replications and trapped animals are required to reach saturation of the species accumulation curve (Thompson et al., 2003). Thus, we may indeed reach a full inventory of reptile species for Nizzanim sands area at the medium or long term (years or decades from the starting point, respectively), with the accumulation of data and mainly data regarding the rarer species. A study conducted in central Florida, aimed at conservation of the scincid Neoseps reynoldsi (morphologically and ecologically similar to Sphenops sepsoides, a common sand dwelling scincid in Israel) found that predictions regarding presence of the species made based on showing photographs of habitats to herpetological experts were significantly more successful than predictions made based on information from the literature (McCoy et al., 1999). Hence, educated guesswork done by experienced, skilled samplers may bring better results in identifying appropriate habitat for specific organisms compared to a model based on literary descriptions. In my study, it will be possible for me to empirically test whether our predictions, based on many years of observational data, regarding the needs and preferences of the various species are correct and to estimate how well we are able to predict the suitable landscape for these species.

Modifications of the habitat following management actions may cause changes in body condition of individuals, due to differences in predation pressures occurring in different habitat types. This has been demonstrated in mice (Arthur et al., 2004) and in lizards (Hawlena & Bouskila, 2006) – following experimentally elevated predation pressures, individual body condition deteriorated, and reductions in reproductive investment, recruitment and average survival were observed. In these studies, the

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predation pressure was elevated by manipulating the study plots in ways that created improved hunting success for potential natural predators (mainly passerines and raptors). In the Sharon region of Israel (central coastal plain), a study was conducted in which stabilized sandy areas that had been manipulated (perennial woody vegetation removal) were naturally re-colonized by psammophilic annual plants and rodents, many of these taxa being endemic to Israel's Mediterranean coastal plain (Kutiel et al., 1997; Kutiel, Peled & Geffen, 2000).

Studies done in Europe regarding active management of coastal dunes have focused mainly on geomorphologic aspects, for instance the work done by Arens et al. (2004) in coastal Netherlands. In the review by Doody (2000) regarding the ecology of conservation and management of Europe's coasts, he remarks that "Sand dunes are not known to be particularly rich in amphibians and reptiles." (p. 124). This is not the case at all in Israel, where reptiles are a substantial component of the fauna of sandy ecosystems, including in coastal sands. The fact that none of the previous studies conducted in the coastal sands examined the responses of the reptilian fauna to dune management has left a deficit in our ability to fully understand the ecosystem's response to vegetation management. My study aims, among other things, to explore whether and to what extent does active management (perennial woody vegetation removal) from stabilized dunes allow psammophilic reptiles to utilize the manipulated habitat, at least in the short term.

The Nizzanim Project

My study was conducted within a long-term, multidisciplinary project initiated in 2004 by a large team of researchers, mainly from Ben-Gurion University of the Negev. Additional partners in this project include researchers from Tel Aviv University, staff from Shiqmim (Nizzanim) Field Study School of the SPNI (Society for the Protection of Nature in Israel), scientists and workers of the JNF (Jewish National Fund = "Keren Kayemet Le'Israel") and scientists and rangers of the INPA (Israel Nature & Parks Authority).

Nizzanim sands were chosen for this project due to the fact that they are the largest

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surviving tract of coastal sand dunes in Israel, they are protected by statutory legislation and there is a substantial amount of preliminary data regarding spatial and temporal changes in these dunes from previous studies (see previous section).

Project and monitoring regime must be designed so information can be gained to evaluate progress and to test hypotheses (by monitoring inputs and/or outcomes). The most robust and powerful experimental design for restorative ecology projects is the M- BARCI design, which incorporates both Before-intervention [B] and After-intervention [A] data, pristine Reference [R] sites, Control [C] sites (damaged, un-restored) and Intervention [I] sites, with all site types represented in Multiple [M] replicates. Alternative experimental designs may be employed if M-BARCI is not feasible:

1. M-BARI (multiple reference and intervention sites) when there are no adequate "control" sites to study;

2. M-BACI (multiple control and intervention sites) when no reference (pristine) sites exist;

3. BARCI, BARI or BACI singular designs, when replication is impossible (for instance, sites are distributed over a large spatial scope).

The M-BARCI design was chosen for the Nizzanim project, since all the necessary components indeed exist at the study area.

The goals or targets of ecological restoration may be set at various ecological levels: (1) species populations, (2) communities, (3) ecological processes, or (4) ecosystem services (Lake, 2001). My project goals were set to the first two levels, species populations and communities. To efficiently monitor restoration projects, it is imperative to choose suitable indicator species or indices. Desirable properties of indicators include:

1. They should be relatively easy and inexpensive to measure;

2. There are no taxonomical difficulties or measuring uncertainties;

3. They are sensitive to the restoration measures;

4. They have different response rates at different time spans;

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5. They are linked with each other in their ecological functioning.

The indicators identified in my project will be presented and discussed I detail, with regards to how well they fit with these criteria. Progress in ecological restoration projects may be detected either by increases in desirable biota or decreases in undesirable biota. Since I worked both at the species and the community level, I measured both of these phenomena.

The various aspects included in this multidisciplinary project involved teams working in tandem, usually on common study plots, each team studying a specific aspect or taxonomic group:

(a) geomorphology

(b) plants (perennial and annual)

(d) reptiles

(e) small mammals (mainly rodents)

The main aims undertaken by the project were to:

(a) Ascertain the impact of woody vegetation cover removal on the rates and patterns of re-establishment by native, sand-dwelling organisms (plants, arthropods, reptiles and small mammals) and on the interaction between them;

(b) Determine the optimal plant cover that will simultaneously facilitate sand mobility and high sand-dwelling biodiversity;

(c) Create a data set of sand dune dwelling taxa and thereby contribute to an understanding of the biodiversity of dune ecosystems;

(d) Evaluate the potential for specific taxa to act as indicators of habitat biodiversity in dune systems;

(e) Model the dispersal rates and patterns of desirable native species (flora and fauna) into newly established shifting dunes from remnant shifting dune refugia.

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In this dissertation I shall present and discuss results and draw conclusions regarding extant reptile assemblages in the various habitat types of Nizzanim sand dunes, and their short-term responses to the manipulation experiment. This I base on data collected in the field during the years 2004-2008.

The importance of this study is, first and foremost, to supply a basic toolbox for assessing reptile community structure in the coastal sands of Israel and their responses to experimental restoration of stabilized dunes to less stabilized states. This has never been previously attempted in Israel in general, and to the best of my knowledge has not been studied on such a large spatial scale in other countries too.

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Study Questions, Hypotheses & Predictions

The Research Questions

My work set out to address three main research questions, each of which could be divided into several practical questions, as follows: 1. What baseline reptile species assemblages occur on natural dunes at Nizzanim? 1a. which reptiles live in Nizzanim sands? 1b. how does dune stabilization level affect reptile species composition? 2. How does dune manipulation (partial perennial vegetation cover removal) affect reptile assemblages at Nizzanim? 2a. what happens to reptile species composition following dune manipulation? 2b. what different effects arise from different manipulation regimes? 2c. do the "desired" reptile fauna colonize the manipulated dunes? 2d. does this manipulation reverse the degradation process (do desert specialist reptiles replace the generalists)? 3. What operational and methodological lessons are to be learned from this study for future herpetofaunal monitoring of coastal sand dune management? 3a. which reptile species are adequate indicators in coastal sands? 3b. which methods should be used for monitoring reptiles in coastal sands? 3c. what questions should be pursued in the future by this and other projects?

Products of This Study

By answering the aforementioned research questions, by analyzing the reptile data and drawing conclusions through rigorous discussion of the reptile response to the manipulation, this study will produce:

1. A check list of reptile species of the Nizzanim sand dunes;

2. Improved operational concepts and tools for managing and restoring coastal dune habitats; 3. A short list of indicator species for monitoring coastal dune reptiles.

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Hypothesis & Predictions

The aforementioned research questions and expected products of this study reside within the realm of applied, practical science. As a doctoral thesis, this work would not be complete without giving consideration to the basic ecological processes at work in the study system. Here I propose a testable hypothesis and my predictions relating to potential outcomes that I discuss later in this thesis.

I hypothesize reptile diversity will show a hump-shaped relationship with the level of ecological disturbance in the habitat. Such a relationship fits the Intermediate Disturbance Hypothesis (IDH; Grime, 1973; Horn, 1975; Connell, 1978), which predicts the highest diversity at intermediate levels of disturbance. IDH stipulates that at high levels of disturbance, species well adapted to such disturbance will dominate the ecosystem, while at low levels of disturbance species adapted to competition shall prevail. I use the IDH as my hypothetical framework. This hypothesis is predicted to have the following six implications on the expected findings in my study, listed here below.

Predictions regarding baseline reptile assemblages:

1. Dune stabilization level (perennial vegetation density) affects reptile assemblages. I predict active, low vegetation cover dunes will present lower overall reptile diversity and abundance with higher proportion of desert specialist species; stabilized, high vegetation cover dunes will present higher overall reptile density and abundance with higher proportion of generalist species.

2. With accordance to IDH, I predict reptile diversity will peak at intermediate disturbance levels, at the semistable dunes, between the extremes of the stabilization gradient (active dunes at the low end and stabilized dunes at the high end). Reptile assemblage will include a mixture of desert specialist species and generalist species. I assume that sand mobility and wind storms constitute "disturbance" in the Nizzanim sands ecosystem (e.g., Perry, 2008), and as stipulated by IDH, that competition will be highest and diversity depressed at low levels of disturbance (stabilized dunes).

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3. Reptile assemblages and specific species, especially those with high affinity to extreme dune types (active or stabilized) will prove to be good indicators for dune stabilization level. I predict at least some of the species can be used as indicators in this as well as future studies.

Predictions regarding effects of dune manipulation on reptile assemblages:

4. Dune manipulation will have both an immediate and a prolonged effect on reptile assemblages. I predict there will be changes in the reptile assemblages following partial vegetation removal, since vegetation density is the dominant factor involved in dune stabilization. The removal of vegetation simulates a level of disturbance, but not as extreme as constant exposure to strong winds causing active dunes. I thus predict that according to the IDH, the diversity of species will increase in the manipulated dunes.

5. Different manipulation regimes will produce different effects on reptile assemblages. I predict that the higher the contrast between vegetation levels before and after manipulation, the effects seen on reptile assemblages will be more pronounced and influence a higher number of species.

6. Vegetation removal will initialize colonization by desert specialist species on the manipulated dunes. I predict that the aforementioned indicators among desert specialist species will start to colonize the manipulated dunes, unless barriers remain between these dunes and source populations.

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Methodology

The Study Site

My study was conducted at Nizzanim sands reserve, situated on Israel’s southern coast, covering an area of roughly 21 square kilometers. The reserve includes two portions: the northern portion (circa 13 km2) recently gained statutory protection (as part of the disengagement plan from the Gaza strip in August 2005) and is readily accessible to the general public year round; the southern portion (circa 8 km2) has been statutorily protected for more than two decades and is a designated military zone, thus is open to civilian activity only on holidays and weekends. The climate is Mediterranean, with annual average temperatures of 19-21°C. The temperature in the hottest month (July) is 26-28°C and that of the coldest month (January) 12-14°C. The annual rainfall ranges between 400 and 500 mm, all of which falls during the winter months (October-March) (climatic data follows Adler, 1985). Geologically, the study area is composed of two Kurkar (aeolianite) ridges that run parallel to the coast. The Kurkar ridges form the basis of dunes which are stabilized at various degrees; the dunes, in turn, are covered with vegetation, from those that are almost bare and active to those that are densely covered and stable.

Areas with 0-10% plant cover are mostly found on surfaces exposed to the wind. These I shall term active dunes from this point on (synonymous with shifting, mobile or unstabilized dunes), see Figure 1. Plant composition of active dunes includes a relatively low percentage of perennials, with most cover provided by annuals. Among the typical perennials that appear mostly at the dune crests or on their windward slopes are maritime grasses (Ammophila arenaria), wormwood (Artemisia monosperma), Cyprus conglomeratus, and Asthenatherium forsskalii. Among the characteristic annuals are Rumex pictus, Ifloga spicata, Lotus halophilus, and Senecio joppensis, the latter being endemic to Israel’s coastal plain (Perry, 2008).

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Figure 1: Active dune. Typical landscape of active dunes (<10% perennial vegetation cover) at Nizzanim reserve, plot A4, May 2008. Photo: Boaz Shacham.

Moderately (10%-40% plant cover) vegetated dunes are mainly covered by perennials, with some annuals. These I shall term semistable from this point on (synonymous with semistabilized dunes), see Figure 2. Perennials on semistable dunes include desert broom (Retama raetam), wormwood, Polygonum palaestinum, and Silene succulenta. Annuals include species that are characteristic of bare active dunes as well as other species, such as Cornyephorus divaricatus, Urospermun picroides, and Trisetaria linearis (Perry, 2008).

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Figure 2: Semistable dune. Typical landscape of semistable dunes (10%-40% perennial vegetation cover) at Nizzanim reserve, plot C1 (densely vegetated interdunes area seen at center left), May 2005. Photo: Boaz Shacham.

Densely (>40% plant cover) vegetated areas are mostly present on the leeward slopes and in depressions between the dunes. These I shall term stabilized from this point on (synonymous with stable dunes), see Figure 3. Species typical of these areas are desert broom and wormwood. In particularly wide and deep depressions, almost 100% of the area is vegetated (taking into consideration the relative coverage of every species within each vegetation layer). In these depressions, Mediterranean mountainous shrubs such as Calicotome villosa and creepers such as Prasium majus predominate (Perry, 2008).

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Figure 3: Stabilized dune. Typical landscape of stabilized dunes (>40% perennial vegetation cover) at Nizzanim reserve, at center gazelles (Gazella gazella) browsing in early morning mist, May 2008. Photo: Boaz Shacham.

Experimental Design

We established 22 study plots in which reptile data were obtained during each of the sampling sessions. The size of each plot was approximately 40 m x 100 m (= 40002 m), with its longitudinal axis parallel to the dune crest and its extent overlapping onto both the windward and leeward sides of the dune. Each plot, whether unmanipulated or manipulated, was surrounded by 10 meter wide buffer strips which had the same percentage cover as the plot "core". To avoid edge effects, I refrained from collecting plot-related biotic samples from these buffer strips. Of these 22 study plots, 17 plots were chosen from a pool of circa thirty potential plot locations initially sampled as part of the "pilot" sampling sessions during the first field season (2004), and five plots were added during the second field season (2005). My experimental design follows the M-BARCI

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design (Chapman & Underwood, 2000; Lake, 2001), in which there are multiple sites for assessing the responses to restoration measures, and the monitoring includes data collected "before" (B) and "after" (A) these measures. The unmanipulated plots include both "reference" (R) and "control" (C) sites, while the manipulated plots constitute the "intervention" (I) sites, as detailed below. Spatial distribution of the study plots is shown in the map of the Nizzanim sands study site (Figure 4).

Table 1: List of the study plots presented in this work (mapped in Figure 4).

Category Plot names M-BARCI type Manipulation regime

Active A1, A4, A5 "reference" (Unmanipulated)

Semistable B1, B6, C1 "reference" (Unmanipulated)

Semistable C5, R5, R6 "control" (Unmanipulated)

Stabilized D4, D6, D8 "control" (Unmanipulated)

MCA C6, R2, R3, R4 "intervention" From semistable to active

MDA D2, D3, D9 "intervention" From stabilized to active

MDB D1, D5, D7 "intervention" From stabilized to semistable

Unmanipulated plots: Twelve uncleared plots were established in dunes with different percentages of vegetation cover: four in active dunes, six in semistable dunes, and three in stabilized dunes. The active plus the three lowest-cover semistable plots constitute our "reference" (R) sites, representing the habitats and biotic compositions we aimed to restore in the manipulated dunes; the stabilized plus the three highest-cover semistable plots constitute our "control" (C) sites, representing the habitats and biotic compositions of the manipulated plots pre-manipulation. All the unmanipulated plots were monitored throughout the study, to provide comparisons of natural habitats with the manipulated (cleared) plots described below. Plots are listed in Table 1, and mapped in Figure 4.

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Figure 4: General map of Nizzanim sands study site. Shown are localities of all study plots (sampled plots listed in Table 1). Courtesy of Yehonathan Rubinstein.

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Manipulated plots: Using heavy mechanical equipment, we manipulated the perennial plant cover of six (6) plots in stabilized dunes that were initially covered by dense, shrub- encroached vegetation (>40%) and one plot in a semistable dune that was initially sparsely vegetated (~30%). At the stabilized dunes the plots were manipulated to a final cover of 10% or 20% (three of each treatment level), at the semistable dune the plot was manipulated to a final cover of 10%. Vegetation was removed at the end of winter of the second year of the project (March 2005). The heavy equipment used was a Caterpillar® shoveling bulldozer, supplied by the JNF, operated and supervised by JNF personnel in the field (Figure 5). The vegetation was removed along strips running parallel and perpendicular to the dune crest, leaving squares of 6 x 6 m unremoved vegetation, thus maintaining intact habitat patches as refugia for animals. Team members of the project, including principal investigators and graduate students (myself included), were in charge of demarcating the 6 x 6 m squares using plastic ribbons and supervising the adherence of the heavy equipment operators to these guidelines (Figure 6). Removed vegetation was amassed in large piles in interdunes areas and destroyed (burned) after precautionary fire lanes were created around them (Figure 7). Configuration of the dunes after the manipulation resembled a checker board, with unmanipulated squares crisscrossed by cleared lanes (Figure 8). Vegetation removal was executed with special permit from the Israel Nature & Parks Authority (INPA permit 2006/21849). These seven manipulated plots were monitored for "before" data prior to manipulation during the first sampling season (2004), and for "after" data starting July 2005. Three additional plots were manipulated from semistable (~30%) vegetation level to active dune level (between 5%- 10%) by INPA personnel by means of heavy machinery, in late autumn of the second year of the project (November 2005), after being sampled for "before" data one month prior to vegetation removal. The ten manipulated plots constitute the "intervention" (I) sites of the M-BARCI design. Shrub clearance was not repeated during the period reported in my work presented here (covering the years 2004-2008), but perennial plant percentage cover was monitored annually at each plot by the flora study team. It may become necessary at some point in the future to repeat shrub clearance at some or all of the manipulated plots. Plots are listed in Table 1, and mapped in Figure 4.

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Figure 5: Bulldozer at work; partially removing perennial vegetation from one of the manipulated stabilized sand dunes (study plot D1), March 2005. Photo: Boaz Shacham.

Figure 6: Plot marking. Foreground, remnant plastic strips used to demarcate lanes for vegetation removal (study plot D1), March 2005. Photo: Boaz Shacham.

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Figure 7: Debris from removal. Foreground, heap of removed vegetation debris ready for burning (circa study plot D2), March 2005. Photo: Boaz Shacham.

Figure 8: Aerial photo of manipulated dunes. Bottom, stabilized manipulated to active (plot D2); top, stabilized to semistable (plot D1), August 2005. Photo: Pua Bar.

34 Boaz Shacham – PhD dissertation

Methods for Sampling the Reptiles

Reptile data were collected using several methods, maximizing the scope of information obtained for species and assemblages. The characteristics of the data obtained by the various sampling methods are summarized and compared in Table 2. Spatial configuration of these methods is described in Figure 9. Detailed description of the reptile sampling methods:

1. Capture of reptiles with pitfall trapping. Plastic buckets (10 liter volume) were buried flush to ground surface in the sand and left open for two consecutive nights in each study plot during each sampling session. Plastic (PVC) rings were partially buried atop each bucket for enhancement of trapping success of burrowing scincid lizards (see Figures 10a, 10b). Reptiles captured in the invertebrate pitfall traps (500 ml plastic cups) used by the arthropod research team were recorded too. Each captured reptile was identified to species level, sexed (age group was recorded when sex was not distinguishable), measured (snout-vent length and tail length, to closest mm, using a ruler), weighed (to nearest 0.1 gram, using an electronic field scale, ACCULAB model PP250B Precision Weighing Balances, 10 Peabody St, Bradford, MA, USA) and marked prior to release (for future identification of recaptures, detailed below), regardless of trap type. Using data from both trap types enhances the reptile sample size: in each plot ten (10) buckets plus thirty (30) invertebrate traps were deployed. The bucket traps were deployed in two 5-bucket "cross" shaped arrays per plot, one bucket at the center of each "cross" and the other four at a distance of approximately 7 meters each from the center. We divided each plot into two "halves" along the dune's width, and deployed each array approximately in the center of each such "half" (Figure 9).The central bucket of each array was termed pitfall #1, the one to its west termed #2, and so on clockwise until the fifth bucket (south of center) termed #5 (Figure 11). The bucket traps were covered by plastic lids between the two trapping nights of each sampling session (see Figure 12), to avoid capture of diurnal species, otherwise forcing me to examine all the traps several times during daylight hours (or risk killing many lizards and other organisms due to heat

35 Boaz Shacham – PhD dissertation

shock). These buckets were filled with sand at the end of each trapping session, to avoid accidental captures of animals during the months between sampling sessions, and wooden sticks or fiberglass poles were used to mark the location of each bucket (see Figure 13). The invertebrate traps were buried flush to the ground along transects of ten traps, at approximately 10 meter intervals, each transect corresponding to one of three geomorphological components of the dune: windward face, dune crest and leeward ("slip face") side. These smaller pitfalls were deployed for periods of 2-4 days (48-96 hours), depending on the goals and logistics of the arthropod team during each specific sampling session, and were left open for the duration of this deployment, at the end of which the traps were unearthed and collected. To minimize accidental death of reptiles due to predators or heat shock, the invertebrate traps were examined at least once daily and any reptiles caught were recorded and transferred to the reptile team for measurement before being released. Since many species of reptiles (especially the larger species) completely avoid both trap types, or cannot physically be trapped in them, the other methods were employed too.

2. Tracks transects. In each study plot, two transects (100 meter length) were cleared for assessing reptile tracks by dragging an old automobile tire (see Figure 14) or with a squeegee in the evening, and reptile tracks were identified and counted early next morning, shortly after examining pitfall trapping results. Thus, we could qualitatively and quantitatively assess nocturnal reptile activity in the plots. In most cases (circa 99%), we are able to identify reptile taxa from tracks at the species level. When we could not identify tracks at species level, these were recorded as "unidentified" with notation of lowest taxonomic level identifiable (example: "unidentified snake"). This was also repeated, as with the pitfall trapping, for two consecutive days (nights) per study plot per sampling session.

3. Lizard activity transects. For each study plot, four transects (80 meter length) were conducted during peak morning activity hours of the diurnal lacertid lizards. This is done after pitfall traps and track transects are examined and recorded. All lizards observed while walking along these activity transects were recorded (time, species, age, sex, distance from line of transect) to facilitate calculation of activity

36 Boaz Shacham – PhD dissertation

and density indices. This method was also repeated, as described for the first two methods above, for two consecutive days per study plot per sampling session. We recorded surface temperature data (in shade of shrub and on exposed sand) at the start and end of each transect bout, to facilitate comparison of seasonal differences and to identify effects of abiotic conditions on lizard activity. Surface temperature was measured using a Raytek ® Raynger ST6 Infrared handheld thermometer (Raytek Corporation, 1201 Shaffer Rd, Santa Cruz, CA, USA). We also recorded comments on climatic conditions when these rarely prevented or reduced lizard activity (e.g. dense cloud cover, strong winds and/or rain).

4. Incidental observations. All reptiles observed incidentally while working in the plots and between the plots, day or night, were recorded and measured (if captured).

Table 2: Characteristics of data obtained by each sampling method. Demographics Morphology levelsActivity density Population Behavior habitat & use N= species nocturnal D = diurnal species Potential issues addressed

by study method

Method

Pitfall trapping N

Track transects N

Lizard transects D

Occasional observations N + D

5. Capture/recapture identification. All lizards captured by pitfall trapping or incidental ("occasional") trapping by hand within the study plots were marked for identification with the commonly used toe-clipping method. In this method the distal phalanges of the marked toes are clipped, usually with the use of small

37 Boaz Shacham – PhD dissertation

surgical scissors or toenail clipper. When done properly by trained individuals, this causes minimal bleeding and the risk of infection is reasonably low. I collected the clipped phalanges for future DNA analysis, recording in detail from which plots, lizards and dates the toes were collected. When snakes or tortoises were encountered, I photographed specimens (when possible, and this was in the majority of cases) from angles that enable individual identification of the animals using specific markings, pigmentation and scars.

LEGEND:

Study plot

Bucket pitfall trap

Track transect

Lizard transect

Figure 9: Spatial scheme of sampling methods. Schematic diagram describing the spatial relations of the main reptile sampling methods employed in my study.

38 Boaz Shacham – PhD dissertation

Sand surface Trap opening

PVC ring

Bucket

Sand

Figure 10a: Schematic side view of bucket pitfall trap (without lid).

Trap opening

Bucket

PVC ring Figure 10b: Schematic top view of bucket pitfall trap (without lid).

39 Boaz Shacham – PhD dissertation

2 1 4 NORTH ~ 7 meters

Figure 11: Pitfall configuration and numbering. Schematic of spatial configuration and numbering system of "cross" bucket pitfall trap array.

Figure 12: Covered pitfall. Pitfall trap temporarily covered by plastic lid (fiberglass rods mark trap loci), plot D3, April 2006. Photo: Boaz Shacham.

40 Boaz Shacham – PhD dissertation

Figure 13: Pitfall exposure. Pitfall trap partially exposed during preparations for sampling, after being buried under surface during a seven- month hiatus between sampling sessions, plot A4, April 2007. Photo: Boaz Shacham.

Figure 14: Track transect. Track transect preparation (erasing) by field technician Arnon Tsairi via used tire, July 2004. Photo: Elli Groner.

41 Boaz Shacham – PhD dissertation

Combined, the methods described above yield results for both diurnal as well as nocturnal reptile activity. Each method has its strengths and weaknesses, and covers certain aspects of reptile ecology and life history, as summarized in Table 2. Some of the methods were more suitable for sampling certain species than others. For example, most of the data on snake activity were obtained from tracks transects. A synthesis of the results obtained by the various methods provides a much broader and better picture of the species inventory and interactions between the species in Nizzanim sands.

Data Analysis Techniques

The data I present were accumulated between the years 2004-2008 (inclusive), during a total of twelve field sessions. We conducted at least two field sessions per year, sessions spanned from five days (two pairs of consecutive nights) to nine days (four pairs of consecutive nights) depending on the amount of plots sampled. The analyses I present exclude study plots that were sampled in less than four out of five of the years.

Most statistical analyses were performed following procedures in Zar (1998) and Coakes & Steed (2001) and ordinations – following procedures in ter Braak & Šmilauer (2002) and Lepš & Šmilauer (2003). Analysis of variance (ANOVA) tests were used to compare reptile species richness and abundance data among the various plot types (SPSS version 15.0, SPSS Inc., 233 S. Wacker Drive, Chicago, IL, USA). Multivariate analyses using the ordination software (CANOCO) were conducted to assess reptile species composition on the various plot types, including tests for effects of environmental variables and changes affected by the habitat manipulation (CANOCO version 4.53, Biometris – Plant Research International, Wageningen, The Netherlands). When relevant, Fisher's Exact Tests were conducted using online resources (Kirkman, 1996 – http://www.physics.csbsju.edu/stats/ ), and Chi Square Tests were calculated manually using Microsoft ® Office Excel 2003 software (Microsoft Corp., 1 Microsoft Way, Redmond, WA, USA).

Multivariate analysis reveals in greater detail the effects of vegetation cover on the species assemblages at the various dune types. Each of the sampling methods employed

42 Boaz Shacham – PhD dissertation

has its strengths and weaknesses, but we did not want to lose the breadth and resolution available by using some sort of combination of all these samples. Data from all sampling methods (tracks transects, pitfall trapping, lizard activity transects and occasional observations) were pooled and combined for this analysis. For each method, raw data were first log-transformed, to dilute differences in magnitude between the most common and the most rare species. The data for each method were then transformed to an ordinal scale of 0 to 5, based within each method's data matrix on the maximal value in that matrix. A common matrix from the four separate matrices was then produced by taking per sample (plot & session) the maximum value per species (the highest of the four values from the four different methods). Thus the common matrix contains the optimal data collected for each species at any given point in time (session) and space (plot). This final matrix was used for multivariate analyses in both CANOCO and SPSS software. Normally, it would be unsound from a statistically view point to combine several data sets, each from a separate methodology, without first testing for homogeneity of samples (sets), but this is not the case here. Our multi-faceted approach to gather qualitative and quantitative information on sand dune reptile assemblages was designed specifically to overcome the shortcomings of each separate sampling method. In many cases, each method targeted different species or groups of species (as described in the previous section), so that in effect the "outliers" of sampling method A were the bulk of the data of sampling method B, and vice versa. I assumed a priori that heterogeneity exists among the data matrices across the four sampling methods we combined, thus there is nothing to be gained by testing for homogeneity.

The need to combine separate data sets collected (each) using different metrics and (to an extent) different species, has been recently acknowledged in the literature (Nichols et al, 2008) but so far the suggested solution referred to the combination of qualitative data only (presence/absence data, Nichols et al, 2008). Lacking referenced examples for such a procedure for quantitative species abundance data, my supervisor and I consulted with senior statisticians and proceeded with the development of the combination of the various data sets as described in my thesis (J. Lepš & P. Šmilauer, personal communication). I opted to include all relevant descriptive statistics and analysis results for the separate data sets prior to the combination procedure, to transparently allow the

43 Boaz Shacham – PhD dissertation

reader to evaluate the trends arising from each sampling method as well as the results derived from combining all methods.

Environmental variables used in various analyses included categorical variables (plot type, season, calendar year) and numerical variables (total perennial vegetation cover proportion, partial perennial cover proportions for three separate life forms of plants, organic matter index from two separate sub-habitats of the plots).

The sources of the perennial vegetation cover were the raw data collected by the botanical team of the Nizzanim project (Perry, 2008). We modified these data to reflect the geomorphological parts of the dunes on which we sampled reptiles: mainly the dune crest, with smaller weight to the windface and slipface of the dune.

An additional description of lizard assemblage composition and the dynamics of changes between the unmanipulated and manipulated plots were represented on an incidence–abundance phase plane. In this technique, the log of the mean density of each species is plotted against the number of plots in which it occurs. Normally, this technique is applied to dynamics in time by drawing arrows between two points for each species measured at different times (Boeken & Shachak, 1998). Since I had sampled during only one season (year) prior to manipulation, in addition to comparing "before" and "after" data for the manipulated plots I also used a slight modification of the technique in which unmanipulated ("control") plots are compared with manipulated plots (following Hawlena & Bouskila, 2006). The trajectories of the species on the phase plane reveal the dynamics of changes in the spatial distribution deriving from the manipulation.

44 Boaz Shacham – PhD dissertation

Results I: Reptile Assemblages at Nizzanim Sands

Species Assemblages on Various Plot Types

The accumulated herpetofaunal inventory of this project includes 25 species: two anuran amphibians, one testudine, twelve lizards and ten snakes. The lizard species span six families: one anguid, one chameleon, two gekkonids, three lacertids, four scincids and one varanid. The snake species span four families: one boid, seven colubrids, one typhlopid and one viper. A summary of this inventory is detailed in Table 3, including categorizing of the species into either of the two ecological categories used in this report: generalist species or desert species. The table lists the incidence frequencies for each species (proportion of samples in which the species was present out of the total number of samples), per plot type and for all samples pooled. The list is arranged in descending order from the most commonly occurring (overall) species to the rarest species. The most commonly occurring species was the scincid Sphenops sepsoides with an incidence frequency of 0.96 (118/123 samples), the rarest were the anuran Hyla savignyi, the lizard Varanus griseus and the snake Coluber rubriceps, all three with incidence frequencies of 0.01 (1/123 samples).

Several trends appear in the accumulated inventory: total species richness is lowest in active dunes, peaks and levels out in the semistable and stabilized dunes; desert species richness peaks in the semistable dunes; generalist species richness increases with increased dune stabilization; desert species proportion decreases with increased dune stabilization. These trends are later mirrored when averaged species richness indices are compared among dune types for the various sampling methods separately (Table 4) and pooled (Table 5). With the exception of the snake Lytorhynchus diadema, lizards dominate the highest ranks of incidence frequency within the accumulated inventory (the top five most common species are lizards). Of the highest ranking (more common) species, the majority are desert species. Among the top ten highest ranking species, seven are nocturnal; this is undoubtedly partially biased by the fact that two out of three of the main methods employed in this project are aimed at nocturnal species.

45 Boaz Shacham – PhD dissertation

Table 3: Summary of species found. With frequencies of incidence per plot type, in descending order of overall frequency (N samples in brackets). active semistable stabilized All Species (Family) Category (N=33) (N=49) (N=41) (N=123) Sphenops sepsoides (Scincidae) desert 0.91 0.96 1.00 0.96 Stenodactylus sthenodactylus (Gekkonidae) desert 0.94 0.98 0.93 0.95 Chalcides ocellatus (Scincidae) generalist 0.30 0.80 0.80 0.67 Acanthodactylus schreiberi (Lacertidae) generalist 0.15 0.73 0.95 0.65 Acanthodactylus scutellatus (Lacertidae) desert 0.97 0.88 0.07 0.63 Lytorhynchus diadema (Colubridae) desert 0.42 0.76 0.63 0.63 Macroprotodon cucullatus (Colubridae) desert 0.24 0.41 0.39 0.36 Spalerosophis diadema (Colubridae) desert 0.12 0.39 0.41 0.33 Typhlops vermicularis (Typhlopidae) generalist 0.09 0.37 0.37 0.29 Psammophis schokari (Colubridae) desert 0.12 0.27 0.20 0.20 Mabuya vittata (Scincidae) generalist 0.00 0.08 0.37 0.15 Testudo graeca (Testudinae) generalist 0.03 0.12 0.15 0.11 Vipera palaestinae (Viperidae) generalist 0.00 0.10 0.20 0.11 Ablepharus rueppellii (Scincidae) generalist 0.00 0.08 0.15 0.08 Chamaeleo chamaeleon (Chamaeleonidae) generalist 0.12 0.04 0.10 0.08 Eryx jaculus (Boidae) generalist 0.00 0.02 0.17 0.07 Malpolon monspessulanus (Colubridae) generalist 0.00 0.02 0.17 0.07 Bufo viridis (Bufonidae) generalist 0.09 0.06 0.02 0.06 Coluber jugularis (Colubridae) generalist 0.00 0.04 0.05 0.03 Cyrtopodion kotschyi (Gekkonidae) generalist 0.00 0.04 0.05 0.03 Mesalina olivieri (Lacertidae) desert 0.03 0.04 0.00 0.02 Ophisaurus apodus (Anguidae) generalist 0.00 0.02 0.05 0.02 Coluber rubriceps (Colubridae) generalist 0.00 0.00 0.02 0.01 Hyla savignyi (Hylidae) generalist 0.00 0.00 0.02 0.01 Varanus griseus (Varanidae) desert 0.00 0.02 0.00 0.01 Total accumulated species N 14 23 23 25 Generalist species N 6 14 16 16 Desert species N 8 9 7 9 % desert species 57.14 39.13 30.43 36.00

46 Boaz Shacham – PhD dissertation

Analysis of the reptile data of the control and reference plots gives us baseline information regarding the species assemblages on the various plot types studied in this project. These data show that active dunes are dominated by three lizard species: the diurnal lacertid Acanthodactylus scutellatus, the nocturnal scincid Sphenops sepsoides and the nocturnal gekkonid Stenodactylus sthenodactylus. All three are desert dwellers, limited in the Mediterranean climatic region along the coast to sand habitats. In semistable dunes two additional lizard species are found: the diurnal lacertid Acanthodactylus schreiberi and the crepuscular scincid Chalcides ocellatus, both of them possess Mediterranean distributions. In stabilized dunes additional Mediterranean species are added to the assemblage, mainly the two diurnal scincids Mabuya vittata and Ablepharus rueppellii, while the desert species A. scutellatus effectively disappears. The latter species characterizes active sand, while A. schreiberi characterizes stabilized sand. Proportional incidence on the various dune types of the two Acanthodactylus and nine other species most commonly observed in this project appears in Figure 15.

Incidence of most common species in plots

Mabuya vittata stabilized Psammophis schokari semistable Typhlops vermicularis active Spalerosophis diadema Macroprotodon cucullatus Lytorhynchus diadema Acanthodactylus scutellatus Acanthodactylus schreiberi Chalcides ocellatus Stenodactylus sthenodactylus Sphenops sepsoides

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 Proportion presence in samples

Figure 15: Proportional incidence of common species. Proportional incidence (0-1) of the eleven most commonly observed species in this project (observed in 15% or more of all samples).

47 Boaz Shacham – PhD dissertation

Plot type was found to have a significant effect on qualitative (species richness) and quantitative (abundance or activity levels) indices observed by all three observational methods described here: track transects, pitfall trapping, lizard activity transects (tested by ANOVA). It is impossible to analyze these data using Repeated Measures ANOVA, since the basic requirement of full symmetry of samples per category could not be obtained (due to various constraints, not all plots were equally sampled in all sampling sessions for all years). However, based on our extremely low recapture rate (<10%) we assume that independence of samples is not violated (low probability of pseudo- replication). All analyses for significance of between-group effects were conducted using Tukey’s Post-hoc test. Descriptive statistics from these analyses are presented in Table 4.

Track transects results: Total number of reptile tracks (summed for all species) on track transects was lowest at active plots, peaked at semistable plots and then slightly decreased at stabilized plots. These differences were statistically significant for active plots versus semistable plots (p=0.013) and stabilized plots (p<0.001), but non-significant for stabilized plots versus semistable plots. Total species richness and generalist species richness in track transects both increased with increased dune stabilization, but this was statistically significant only for active plots versus semistable (p<0.01) and stabilized plots (p<0.01), not for stabilized plots versus semistable plots. Desert species richness in track transects peaked at the semistable plots, but the differences were statistically significant only for active versus semistable plots (p<0.01).

Pitfall trapping results: Number of individuals (summed for all species) trapped and total species richness increased with increased dune stabilization, this was statistically significant only for stabilized plots versus active plots (p<0.01). Generalist species richness increased with increased dune stabilization, this was significant (p<0.01) except for active versus semistable plots. Desert specialist species richness in pitfall trapping was not significantly different between plot types.

Lizard activity transects results: Total number of reptile observations (summed for all species) was significantly higher in active plots versus semistable and stabilized (p<0.001) plots, and non-significantly higher in stabilized versus semistable plots. There

48 Boaz Shacham – PhD dissertation

were no significant differences between plot types regarding total species richness. Generalist species richness increased with increased dune stabilization, this was statistically significant in all cases (p<0.01). Desert species richness decreased with increased dune stabilization, this was significant for both active and semistable plots versus stabilized plots (p<0.001) but not significant for active versus stabilized plots.

Table 4: Average observations and species richness. Summary of average quantitative and qualitative data per plot type and overall (SD = standard deviations), for main sampling methods employed (track transects, pitfall trapping, lizard activity transects). Plot type Active Semistable Stabilized All (mean ± SD) (mean ± SD) (mean ± SD) (mean ± SD) Method Method N samples 30 48 39 117 N tracks 17.68 ±9.161 29.73 ±17.643 26.50 ±14.779 25.57 ±15.564 Total species N 3.40 ±1.329 5.00 ±1.598 5.18 ±1.760 4.65 ±1.743 Desert species N 2.80 ±0.961 3.71 ±1.202 3.51 ±1.254 3.41 ±1.212 Generalist species N 0.60 ±0.724 1.29 ±0.713 1.67 ±1.060 1.24 ±0.934 % desert species 85.77 ±17.522 74.70 ±11.313 69.60 ±16.076 75.84 ±15.888 Tracks transects Tracks transects N samples 32 46 35 113 N reptiles trapped 2.63 ±2.211 4.57 ±3.038 6.51 ±5.236 4.68 ±4.021 Total species N 1.47 ±0.842 1.83 ±0.950 2.46 ±1.166 1.94 ±1.069 Desert species N 1.44 ±0.840 1.48 ±0.809 1.59 ±0.549 1.50 ±0.738 Generalist species N 0.03 ±0.177 0.35 ±0.482 0.87 ±0.951 0.44 ±0.712 % desert species 98.21 ±9.449 82.01 ±28.808 72.72 ±26.153 82.92 ±26.046 Pitfall traps traps Pitfall N samples 30 42 37 109 N observations 8.78 ±5.841 3.20 ±2.583 3.74 ±2.348 4.92 ±4.394 Total species N 1.00 ±0.263 1.36 ±0.656 1.27 ±0.608 1.23 ±0.571 Desert species N 0.967 ±0.183 0.81 ±0.397 0.027 ±0.164 0.59 ±0.495 Generalist species N 0.03 ±0.183 0.55 ±0.550 1.24 ±0.597 0.64 ±0.688 % desert species 98.28 ±9.285 64.96 ±35.001 1.389 ±8.333 52.24 ±45.395 Lizard transects Lizard transects

49 Boaz Shacham – PhD dissertation

Desert specialist species proportion (within total species richness) decreased with increased dune stabilization in all three sampling methods, most markedly in the lizard activity transects.

When species richness data are pooled from all methods mentioned above, and occasional (incidental) observations are also added, the differences between the plot types are more pronounced and more highly significant, for all species richness indices (tested by ANOVA). As before, all analyses for significance of between-group effects were conducted using Tukey’s Post-hoc test. This pooling is based on counts of all species present per plot per sample, disregarding quantitative data, which were analyzed separately and shall be presented later in this chapter.

Total species richness increased with increased dune stabilization, this was statistically significant for active plots versus stabilized or semistable plots, but was not significant for stabilized versus semistable plots (Figure 16). Number of desert specialist species was significantly higher in the semistable plots compared to both active and stabilized plots, but there was no significant difference for this index between active versus stabilized plots (Figure 16). Number of generalist species increased significantly with increased dune stabilization in all cases (Figure 16). Proportion (in percent) of desert specialist species decreased significantly with increased dune stabilization in all cases (Figure 17). The results from these analyses are summarized in Table 5.

Table 5: Average species richness pooled for all methods. Summary of average species richness per plot type and overall (SD = standard deviations). Plot type Active Semistable Stabilized All (mean ± SD) (mean ± SD) (mean ± SD) (mean ± SD) N samples 33 49 41 123 Total species N 4.55 ± 1.438 7.22 ± 1.829 7.27 ± 2.367 6.52 ± 2.266 Desert species N 3.76 ± 1.146 4.69 ± 1.402 3.63 ± 1.22 2.43 ± 1.605 Generalist species N 0.79 ± 0.781 2.53 ± 0.915 3.63 ± 1.624 4.09 ± 1.361 % desert species 84.22 ± 15.362 64.57 ± 10.422 51.08 ± 12.079 65.35 ± 17.819

50 Boaz Shacham – PhD dissertation

Average species richness per plot type 10 b b

a 6

N Total species Total N 2

6 c

4 b

2 a

species Generalist N 0 10

6 b a a 4

2 NDesert species

active semistable stabilized Figure 16: Average species richness indices (total species, generalist species, and desert species) compared among plot types, pooled for all reptile observation methods (summarized in Table 5). Letters represent statistical significant differences.

51 Boaz Shacham – PhD dissertation

Average % Desert specialist species 100%

a b c

75% 51.08 64.57 84.22 50%

%species 25%

0% desert active semistable stabilized generalist Figure 17: Average proportion of desert specialist species (of total species richness) at the different plot types, pooled for all reptile observation methods (see Table 5). All differences were statistically significant, as indicated by letters.

52 Boaz Shacham – PhD dissertation

Effects of Vegetation Cover on Reptile Species Assemblages

Multivariate analysis techniques were applied to a matrix devised from normalizing and combining raw data from all sampling methods used (track transects, pitfall trapping, lizard activity transects and occasional observations), as described in the methodology chapter. Significance of vegetation cover and related indices on the reptile assemblages observed in the study plots was tested using the RDA (redundancy analysis) procedure of CANOCO 4.53 software. Forward selection model was used to identify the main effects, testing for the significance of each variable in descending order of percent variation explained by the given variable. All four vegetation indices (variables) tested were found to have a statistically significant effect: proportion "Bush" cover (explained 29% of total variation, F=48.78, p=0.002), proportion "Grass" cover (explained additional 2% of total variation, F=3.39, p=0.002), proportion "Semi-bush" cover (explained additional 1% of total variation, F=2.61, p=0.012), proportion total perennial "Cover" (explained additional 1% of total variation, F=2.44, p=0.028). Due to lack of organic matter (OM) samples for some of the plots analyzed, I could not test for the effect of the associated variables across the complete data set, but when tested separately for OM-sampled plots, these variables were not found to have a significant effect. This is probably due to the strong auto-correlation of organic matter indices with the total vegetation cover and the other direct measures of vegetation (Bush, Grass and Semi-bush). Principle component analysis (PCA) of these data in CANOCO software produced an ordination plot (Figure 18) showing the distribution of the samples according to the species scores observed. Each plot type (active, semistable and stabilized sand) appears to form its own distinct cluster, with slight overlaps in some cases. There is some overlap between active and semistable plots, and also some overlap between semistable and stabilized plots, but effectively none between active and stabilized plots. The red arrows represent the vectors of the environmental variables included in this analysis, projected in the ordinational space but not used to calculate the distribution of the samples on the axes. The variables "Bush" and "Cover" (total perennial cover) show strong association with the cluster of stabilized plots, the variable "Semi" (semi-bush cover) shows an association with semistable plots, and the variable "Grass" shows a strong association with active plots.

53 Boaz Shacham – PhD dissertation

Active

Semistable

Stabilized

Figure 18: Multivariate analysis of un-manipulated plots. PCA (principle component analysis) of the samples according to species data. The environmental variables (red arrows) are merely projected in this analysis, not affecting the samples' location of the axes of ordinational space, but showing the vector associated with each such variable along the two main axes of this ordination. Yellow circles represent the active plots (N=33), bright green diamonds semistable plots (N=49) and dark green squares stabilized plots (N=41). Species vectors on the two main ordination axes appear as blue arrows.

54 Boaz Shacham – PhD dissertation

Seasonal Effects on Reptile Activity and Abundance

The fact that the data were accumulated from different seasons (spring, summer or autumn) complicates analysis but allows comparing and identifying seasonal effects. The largest set of samples was collected during spring field sessions (N=78, Figure 19), the smallest set during summer field sessions (N=42, Figure 20) and the second largest during autumn field sessions (N=69, Figure 21). The overall variation within each plot type and the overlap between plot types seems to be lowest in the summer sessions, but this is probably affected by the smaller sample size for this season. Data collected during spring display the highest variation within each plot type and relatively higher overlap between the plot types compared with the other seasons. When seasons are added to the ordination drawing, the vector for "spring" are inversed in direction to those for "summer" and "autumn" (see Figure 18). Generally speaking, there are greater resemblances in distribution of the samples in the diagrams for summer and autumn when visually comparing each of these seasons to spring.

These data were subjected to multivariate tests (SPSS 15.0 software), including as effects the variables year, season and plot type ("code"), as well as between-variable interactions. The same 17 reptile species included in the PCA and RDA analyses described in this chapter were included in the model (relatively rare species omitted). It is important to note that these are the same data I had combined, transformed and standardized from all four sampling methods, as described previously in this chapter. Model design was: Intercept + Year + Season + Code + Year*Season + Year*Code + Season*Code + Year*Season*Code. The tests used by the software included Pillai's Trace, Wilk's Lambda, Hotelling's Trace, and Roy's Largest Root. Intercept, year, season, plot type (code) were all found to be statistically significant (p<0.001). The only interaction found statistically significant by all four tests used by the software was Season*Code. The other three interactions were non-significant by all tests except for Roy's Largest Root, which found all the interactions significant (p<0.001). Some of the species showed significant seasonal effects, while others did not. Four of the species showed a similar seasonal pattern, in which the highest average presence levels

55 Boaz Shacham – PhD dissertation

(compared with the other species) occurred in summer, the lowest in spring, autumn being intermediate: S. sepsoides, Lytorhynchus diadema, Macroprotodon cucullatus and C. ocellatus. Of these four, the first two are considered desert specialists, while M. cucullatus is of Mediterranean distribution and C. ocellatus is considered a generalist species. In the desert specialist A. scutellatus, average presence levels were significantly lowest in spring, with no significant difference between summer and autumn. In the generalist M. vittata, average presence levels were significantly lowest in autumn, with no significant difference between spring and summer.

Separate analysis for each of the three sampling methods also shows either trends or statistically significant differences for nearly all the species. The track transects results show the highest species richness and tracks (activity) abundance in summer, lowest in spring and intermediate in autumn. These trends remain consistent when generalist species or desert specialist species are analyzed separately. The pitfall trapping results show nearly identical trends (but less of these were found to be significant) – highest abundance and species richness of trapped animals in summer, lowest in spring and intermediate in autumn. The lizard activity transects results show different seasonal trends, in which the highest abundance of animals was found in autumn, the lowest in spring and summer is intermediate (albeit closer to the autumn results). The fact that the highest lizard abundance appears in autumn activity transects is may be associated with the high abundance of A. scutellatus hatchlings, born in this area usually from late July until late September (Shacham, unpublished data).

In general, my findings accord with our current knowledge about the life history and seasonality of the reptile species found at Nizzanim. As described here, many of the nocturnal desert specialist species showed peak activity levels and presence during the summer months, while diurnal lizards (especially lacertids) peaked during autumn months, the latter coinciding with expected appearance of hatchlings. The pros and cons of the potential sampling seasons shall be discussed in depth in later chapters.

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Active

Semistable

Stabilized scutellatus schreiberi

Figure 19: Spring season data. PCA (principle component analysis) of the samples according to species data collected during spring field sessions (May 2004; April 2005; April 2006; April 2007; May 2008). Yellow circles represent active (N=13), bright green diamonds semistable (N=30) and dark green squares stabilized plots (N=35).

Active scutellatus schreiberi Semistable

Stabilized

Figure 20: Summer season data. PCA (principle component analysis) of the samples according to species data collected during summer field sessions (July 2004; July 2005; August 2006). Yellow circles represent active (N=9), bright green diamonds semistable (N=11) and dark green squares stabilized plots (N=22).

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Active

scutellatus Semistable schreiberi Stabilized

Figure 21: Autumn season data. PCA (principle component analysis) of the samples according to species data collected during autumn field sessions (September 2004; September 2005; September 2007; September 2008). Yellow circles represent the active plots (N=11), bright green diamonds semistable plots (N=28) and dark green squares stabilized plots (N=30).

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Patterns Seen in Diurnal Lizard Observations

Average number of Acanthodactylus scutellatus observed in lizard transects decreased with increased dune stabilization, this was statistically significant (p<0.01) in all comparisons between plot types (ANOVA). Average number of A. schreiberi observed in lizard transects increased with increased dune stabilization, this was statistically significant in nearly all comparisons, except for active plots versus semistable plots (p=0.085). These averages are depicted in Figure 22.

Table 6: Average numbers of Acanthodactylus lizards, ± SD (standard deviations) observed in the lizard transects, per plot type (presented in Figure 22). Plot type (N transects) Active (62) Semistable (91) Stabilized (74) A. scutellatus 8.79 ± 6.46 2.10 ± 2.68 0.04 ± 0.35 A. schreiberi 0.03 ± 0.25 0.96 ± 1.64 3.42 ± 2.58

average N lizards per transect

16 A. scutellatus 12 A. schreiberi 8

lizards N 4

mobileactive semistable stabilized

Figure 22: Average numbers of Acanthodactylus lizards, observed in the lizard transects. A. scutellatus decrease and effectively disappear with increased dune stability levels, while A. schreiberi show an inverse picture.

59 Boaz Shacham – PhD dissertation

When total sums of observed Acanthodactylus lizards are compared across plot types using Chi2 tests, the differences are highly significant (p<0.0001). The sums used as "observed" data for the purpose of calculating the "expected" contingency table are presented in Table 7.

Table 7: Total numbers of Acanthodactylus lizards observed (in the lizard transects), used as the basis for "observed" data for Chi2 test. Plot type N transects A. scutellatus A. schreiberi Total Active 57 498 2 500 Semistable 91 191 87 278 Stabilized 74 3 253 256 Total -- 692 342 1031

The best method for graphically displaying the complementary nature of the distribution of the two Acanthodactylus species is an incidence/abundance phase plane (Hawlena & Bouskila, 2006). This is achieved by plotting incidence levels (proportion of samples, from total dataset, in which given species was present) against abundance levels (logarithmic transformation of the average observed specimens, per sample, of given species). Such a graph is shown in Figure 23, displaying the incidence/abundance of A. scutellatus as virtually the mirror image of that for A. schreiberi, the former showing decreased incidence and abundance levels along the gradient of increased vegetation density (dune stability) while the latter shows increased incidence and abundance levels along the same gradient. The data show that at intermediate vegetation density levels (semistable dunes), A. scutellatus had higher incidence and abundance levels compared to A. schreiberi. Each species has what seems to be non-suitable habitat, in which incidence levels are virtually zero: for A. scutellatus, the stabilized dunes and for A. schreiberi, the active dunes. The relationship seen at Nizzanim sands between these two species may or may not be similar to that seen at other sites where the two are geographically sympatric, the pair would probably be indicative as eco-indicators for herpetofauna elsewhere, but local calibrations must be made for each geographic site.

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Incidence/Abundance of Acanthodactylus species 1.5

0.5

0 0.2 0.4 0.6 0.8 1 -0.5

log Abundance log A.scutellatus - mobileactive -1 A.scutellatus - semistable

-1.5 A.scutellatus - stabilized A.schreiberi - mobileactive -2 A.schreiberi - semistable A.schreiberi - stabilized Incidence (proportion)

Figure 23: Incidence/abundance phase planeof Acanthodactylus species observed (in the lizard transects). A. scutellatus show decreased incidence and abundance levels as dune stability increases (dashed arrows), while A. schreiberi show the exact opposite: increased incidence and abundance levels as dune stability increases.

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Results II: Response of Reptiles to Dune Management

Changes in Reptile Assemblages Following Management Actions

Comparison of the reptile data from the manipulated plots to those collected from the control and reference plots facilitates assessment of the effects of the management actions on species assemblages within the various plot types studied in this project. The averages of species richness indices (total species richness; generalist species richness; desert specialist species richness; percent desert species) are summarized in Table 8, and (excluding percent desert species) depicted in Figure 24. Significance levels (p-values) of multiple comparisons among the plot types are presented in Tables 9, 10, 11 and 12. These indices are based on combined data (species counts) from all observation methods used (track transects, pitfall trapping, lizard activity transects and occasional observations). The main effects and phenomena observed were as follows:

Effects in MCA plots – plots manipulated from semistable vegetation cover ("C") to active vegetation cover ("A"), included plots C6, R2, R3 and R4. Following manipulation, these plots did not differ significantly in average total species richness from any of the other plot types, in effect placing them as interim between the active and the semistable plots. Prior to manipulation, these plots had been semistable, thus had a significantly higher total species richness compared to active plots. The MCA plots have a total species richness that is lower by one species compared to stabilized plots and manipulated stabilized plots (MDA, MDB), but this difference too is not significant (Table 9).

Average generalist species richness in MCA plots was significantly higher than that of active plots, significantly lower than that of stabilized plots and manipulated stabilized plots (MDA, MDB) but not significantly different than that of semistable plots (which were the baseline state of the MCA prior to manipulation) (Table 10).

Average desert specialist species richness in MCA plots was significantly lower than that of semistable plots, but not significantly different than that of active, stabilized and manipulated stabilized (MDA, MDB) plots. Average percent of desert specialist species

62 Boaz Shacham – PhD dissertation

in MCA plots was significantly lower than that of active plots, but not significantly different than that of all other plot categories (Tables 11 and 12).

Thus, following manipulation, MCA plots shifted from semistable plots towards active plots with regards to desert specialist species richness but remained unchanged with regards to total and generalist species richness.

Effects in MDA plots – plots manipulated from stabilized vegetation cover ("D") to active vegetation cover ("A"), included plots D2, D3 and D9. Following manipulation, these plots retained a significantly higher average total species richness compared to active plots, but did not differ significantly in total species richness from any of the other plot types (Table 9).

Average generalist species richness in MDA plots was significantly higher than that of active plots, semistable plots and MCA plots, but not significantly different than that of stabilized plots and MDB plots (Table 10).

Average desert specialist species richness in MDA plots was significantly lower than that of semistable plots, but not significantly different than any of the other plot types (Table 11). Average percent of desert specialist species in MDA plots was significantly lower than that of active and semistable plots, but not significantly different than that of stabilized plots, MCA plots and MDB plots (Table 12).

Thus, MDA plots were not significantly affected by the manipulation in any of the species richness indices described here.

Effects in MDB plots – plots manipulated from stabilized vegetation cover ("D") to semistable vegetation cover ("B"), they include plots D1, D5 and D7. Following manipulation, these plots retained a significantly higher average total species richness compared to active plots, but did not differ significantly in total species richness from any of the other plot types (Table 9).

63 Boaz Shacham – PhD dissertation

Average generalist species richness in MDB plots was significantly higher than that of active plots, semistable plots and MCA plots, but not significantly different than that of stabilized plots and MDA plots (Table 10).

Average desert specialist species richness in MDB plots was significantly lower than that of semistable plots, but not significantly different than any of the other plot types (Table 11). Average percent of desert specialist species in MDB plots was significantly lower than that of active and semistable plots, but not significantly different than that of stabilized plots, MCA plots and MDA plots (Table 12).

Thus, MDB plots were not significantly affected by the manipulation in any of the species richness indices described here. Furthermore, according to these indices the two treatment levels of manipulation tested here (MDA and MDB) are practically discernable, as depicted in Figure 24.

Most of the trends seen in the non-manipulated plots are mirrored in the manipulated plots, when arranged in escalating order from the lowest degree of vegetation cover at MCA to the highest at MDB plots (see Figure 24). Total species richness generally increases from the lowest to the highest vegetation cover categories in both non- manipulated and manipulated plots. Generalist species richness also generally increases in the same direction. While desert specialist species richness peaks at the semistable plots among the non-manipulated plots, it remains unchanged (nearly identical) among all three manipulation categories. Proportion (percent) of desert specialist species decreased significantly with increased vegetation cover in the non-manipulated dunes, but non- significantly in the manipulated dunes (Figure 25; significance levels in Table 12).

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Average species richness per plot type

10 b b b 8 b ab a 6

2 N Total species

0 10

6 d d cd bc 4 b a 2

N Generalist species0 10

b 6 a a a a a 4

N Desert species 0 active semistable stabilized MCA MDA MDB

Figure 24: Average species richness indices at the different plot types, pooled for all reptile observation methods. Acronyms used for manipulated plots: MCA = manipulated from semistable to active sand; MDA = manipulated from stabilized to active sand; and MDB = manipulated from stabilized to semistable sand. Significant differences between plot types are represented by small case letters.

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Average % Desert specialist species 100% a b c bc c c

75% 84.22 64.57 51.08 59.53 50.71 47.09 50%

species % 25%

0% desert active semistable stabilized MCA MDA MDB generalist Figure 25: Proportion of desert specialist species at the different plot types, pooled for all observation methods. Acronyms used for manipulated plots: MCA = manipulated from semistable to active sand; MDA = manipulated from stabilized to active sand; and MDB = manipulated from stabilized to semistable sand.

Table 8: Average species richness indices at the different plot types (SD = standard deviations). Significance levels for plot comparisons appear in Tables 9-12. Plot type Active Semi- Stabilized MCA MDA MDB stable

N samples 33 49 41 20 24 22 Average Total 4.55 ± 7.22 ± 7.27 ± 6.05 ± 7.33 ± 7.55 ± species N ± SD 1.438 1.829 2.367 2.064 2.057 1.683 Average Desert 3.76 ± 4.69 ± 3.63 ± 3.65 ± 3.63 ± 3.55 ± species N ± SD 1.146 1.402 1.220 1.348 1.096 1.184 Average Generalist 0.79 ± 2.53 ± 3.63 ± 2.40 ± 3.71 ± 4.00 ± species N ± SD 0.781 0.915 1.624 1.536 1.732 1.512 % desert species 84.22 ± 64.57 ± 51.08 ± 59.53 ± 50.71 ± 47.09 ± ± SD 15.362 10.422 12.079 21.711 13.284 15.925

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Table 9: Total species richness significance levels (p-values), for multiple comparisons (Tukey HSD post-hoc tests) between plot types (data in Table 8). Semistable Stabilized MCA MDA MDB Active 0.000 0.000 0.073 0.000 0.000 Semistable X 1.000 0.207 1.000 0.987 Stabilized X 0.198 1.000 0.994 MCA X 0.250 0.131 MDA X 0.999

Table 10: Generalist species richness significance levels (p-values), for multiple comparisons (Tukey HSD post-hoc tests) between plot types (data in Table 8). Semistable Stabilized MCA MDA MDB Active 0.000 0.000 0.000 0.000 0.000 Semistable X 0.002 0.999 0.007 0.000 Stabilized X 0.011 1.000 0.905 MCA X 0.018 0.002 MDA X 0.977

Table 11: Desert specialist species richness significance levels (p-values), for multiple comparisons (Tukey HSD post-hoc tests) between plot types (data in Table 8). Semistable Stabilized MCA MDA MDB Active 0.014 0.998 1.000 0.999 0.990 Semistable X 0.001 0.024 0.010 0.006 Stabilized X 1.000 1.000 1.000 MCA X 1.000 1.000 MDA X 1.000

67 Boaz Shacham – PhD dissertation

Table 12: Desert specialist proportion significance levels (p-values), for multiple comparisons (Tukey HSD post-hoc tests) between plot types (data in Table 8). Semistable Stabilized MCA MDA MDB Active 0.000 0.000 0.000 0.000 0.000 Semistable X 0.000 0.764 0.002 0.000 Stabilized X 0.252 1.000 0.896 MCA X 0.318 0.057 MDA X 0.955

Multivariate analysis of all plot categories using CANOCO software (Lepš & Šmilauer, 2003) reveals that the only manipulation category that shows some similarity to the intended target (non-manipulated) dunes are MCA plots. The ordination plot in Figure 26 clearly shows much overlap in all three manipulation categories between plots of the original (pre-manipulation) state and those following the manipulation actions. There is especially much overlap between the MDA and MDB plots types, and both seem to greatly overlap with the stabilized plots (which are their baseline pre-manipulation state).

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Active

Semistable

Stabilized

Figure 26: Multivariate analysis of all plot types pre- and post-manipulation. PCA (principle component analysis) of the samples according to species data. The environmental variables (red arrows) are merely projected in this analysis, not affecting the samples' location of the axes of ordinational space, but indicating the vector associated with each such variable. Yellow circles represent the active plots (N=33), bright green diamonds semistable plots (N=49), dark green squares stabilized plots (N=41), yellow diamonds semistable plots treated to active (MCA, N=20), yellow squares stabilized plots treated to active (MDA, N=24) and bright green squares stabilized plots treated to semistable (MDB, N=22). Species vectors on the two main ordination axes appear as blue arrows.

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Trajectory of Management Effects Through Time

Multivariate analysis using CANOCO software (Lepš & Šmilauer, 2003) facilitates detection of the evolution of the post-management effects through time. These analyses take into account both qualitative and quantitative information regarding the species assemblages at the various dune types. Data from all sampling methods (tracks transects, pitfall trapping, lizard activity transects and occasional observations) were pooled and combined to create a common matrix for this analysis, as described in the methods chapter.

When the data used to create Figure 26 is plotted separately for each calendar year, it is possible to visualize the differences between plot types through time. Data for each year from 2004 until 2008 is depicted in Figures 27 to 31, respectively. The non- manipulated plots (active, semistable and stabilized) appear to be fairly well differentiated in all the years, with only slight overlap of samples between plot types. The manipulated semistable plots (MCA) seem to maintain an intermediate position between the active and the semistable plots; this is more pronounced in 2006 compared to the later years (in 2005 only one MCA plot was sampled, since 2006 four such plots were sampled in most years). The manipulated stabilized plots (MDA, MDB) seem to aggregate close to the center of gravity of the stabilized plots – hence, their distribution in the ordination space is similar to that of their original state before the manipulation.

The data collected between the years 2004 to 2007 were used for a time-series analysis, resulting in a principle response curve (PRC) in which the trajectory of each plot type through time is shown (Figure 32). This analysis includes only plots which had been sampled in all four years, thus only one MCA plot is represented in it (plot C6; the other MCA plots – R2, R3 and R4 – were not sampled in 2004). The PRC shows that initially, all three manipulation levels deviate from the basal (pre-manipulation) states of their respective plot types, seemingly towards the values observed for the target plot types. In later years, from 2006 onwards, the MCA plot maintains a value close to the active (A) plots, while the MDA and MDB plots revert to values closer to the baseline represented by stabilized plots (D).

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Active

Semistable

Stabilized

Figure 27: Multivariate analysis of 2004 sessions. PCA (principle component analysis) of the samples according to species data collected during three field sessions of 2004 (May, July, September 2004). Yellow circles represent active (N=6), bright green diamonds semistable (N=7) and dark green squares stabilized plots (N=9). Species vectors appear as blue arrows.

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Active

Semistable

Stabilized

scutellatus schreiberi

Figure 28: Multivariate analysis of 2005 sessions. PCA (principle component analysis) of the samples according to species data collected during three field sessions of 2005 (April, July, September). Yellow circles represent active (N=9), bright green diamonds semistable (N=15), dark green squares stabilized plots (N=12), yellow diamonds plots manipulated from semistable to active (MCA, N=2), yellow squares plots manipulated from stabilized to active (MDA, N=6) and bright green squares plots manipulated from stabilized to semistable (MDB, N=7). Species vectors appear as blue arrows.

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Active

Semistable

Stabilized

scutellatus schreiberi

Figure 29: Multivariate analysis of 2006 sessions. PCA (principle component analysis) of the samples according to species data collected during two field sessions of 2006 (April, August). Yellow circles represent the active plots (N=6), bright green diamonds semistable plots (N=10), dark green squares stabilized plots (N=6), yellow diamonds plots manipulated from semistable to active (MCA, N=5), yellow squares plots manipulated from stabilized to active (MDA, N=6) and bright green squares plots manipulated from stabilized to semistable (MDB, N=6). Species vectors appear as blue arrows.

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Active

Semistable

scutellatus Stabilized schreiberi

Figure 30: Multivariate analysis of 2007 sessions. PCA (principle component analysis) of the samples according to species data collected during two field sessions of 2007 (April, September). Yellow circles represent the active plots (N=6), bright green diamonds semistable plots (N=11), dark green squares stabilized plots (N=6), yellow diamonds plots manipulated from semistable to active (MCA, N=7), yellow squares plots manipulated from stabilized to active (MDA, N=6) and bright green squares plots manipulated from stabilized to semistable (MDB, N=6). Species vectors appear as blue arrows.

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Active

Semistable

Stabilized

scutellatus schreiberi

Figure 31: Multivariate analysis of 2008 sessions. PCA (principle component analysis) of the samples according to species data collected during two field sessions of 2008 (May, September). Yellow circles represent the active plots (N=6), bright green diamonds semistable plots (N=6), dark green squares stabilized plots ( N=6), yellow diamonds plots manipulated from semistable to active (MCA, N=6), yellow squares plots manipulated from stabilized to active (MDA, N=6) and bright green squares plots manipulated from stabilized to semistable (MDB, N=3). Species vectors appear as blue arrows.

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latus AA

MCA BC

MDB DD MDA

2004 2005 2006 2007 YEAR

eri

M M M M M M

Figure 32: Time-series analysis of assemblages' response. PRC (principle response curve) based on time-series analysis of the data from plots that were sampled consistently during all the years 2004-2007 (inclusive). In this analysis the stabilized plots (DD) served as the baseline (zero) for the other plot types. The graph on the right gives the species scores from this analysis.

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Effects of Management on Lizard Body Condition

The changes that took place after the manipulation may have profound effects on individual reptiles living in the manipulated plots. Partial vegetation removal potentially changes the dynamics of competition for resources, predation pressure (actual or perceived), thermoregulation behavior and other factors. This section presents results relating to the physical condition of the two most abundant lizard species caught in the pitfall traps: Sphenops sepsoides and Stenodactylus sthenodactylus. The physical attributes presented include the relative incidence of tail injury and body condition index, compared among the different plot types.

In S. sepsoides tail injury incidence was found to be extremely high, and ranged from 59% in the semistable plots to nearly 74% in the MDA plots. Among the non- manipulated plots, tail injury rate was highest in the active plots and very similar between the semistable and stabilized plots, but none of the differences were statistically significant. Among the manipulated plots, it appears as if tail injury rate increases with intensity of the manipulation: it was highest in the MDA plots (manipulated from stabilized to active vegetation level), lower in the MCA plots (manipulated from semistable to active) and lowest in the MDB plots (manipulated from stabilized to semistable vegetation), but these differences were also not statistically significant. The numbers of animals with or without tail injury and the calculated proportion of injured animals are summarized in Table 13 and displayed in Figure 34. Significance levels (p- values) of multiple comparisons between the plot types are given in Table 14. Ratio body index (BI) was calculated for all animals captured, following Andrews & Wright (1994), see formula in Figure 33.

BI = {lizard mass (gr)} 0.3 / {lizard body length (mm)}

Figure 33: Formula used for calculating lizard ratio body index (BI).

Average BI (body index) was compared for animals with intact (non-injured) tails among all plot types. In non-manipulated plots, BI decreased with increased vegetation cover, this was statistically significant for all comparisons except for active versus

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semistable. In MCA plots BI increased compared to the baseline in semistable plots, but this was not statistically significant. In MDA plots BI increased but was not significantly different from any on the other plot types, but this deviates from their original (stabilized) state which should be significantly different from both active and semistable plots. In MDB BI slightly increased compared to stabilized dunes, but remained significantly lower than in active plots and non-significantly lower than in semistable plots. The MDB plots show similar, but less pronounced change compared to the change in MDA plots. The average BI indices for all plot types are shown in Figure 35, significance levels (p- values) of multiple comparisons between the plot types are given in Table 15. Summarizing results for S. sepsoides, trends seen in the more aggressive treatment regimens, MCA and MDA, seem to mirror the situation in the natural (non-manipulated) active plots. Exemplars of this species are shown in Figure 36.

% injured tails of Sphenops sepsoides intact injured

100%

80%

60%

40%

20%

0% active (36) semistable stabilized MCA (33) MDA (53) MDB (65) (120) (154)

Figure 34: Tail injury rate in S. sepsoides. Proportion of S. sepsoides captured in pitfall traps with intact tails versus animals with injured (broken or regenerated) tails. Total sample size per plot type is parenthesized. Percent injured tails was elevated in all treated plot types (MCA, MDA and MDB) compared with the non-manipulated baseline plots (semistable, stabilized), but this was not statistically significant.

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Table 13: Tail injury rate in S. sepsoides. Accumulated numbers of S. sepsoides captured in pitfall traps divided into animals with intact tails and animals with injured (broken or regenerated) tails. Proportion of animals with injured tails (in percent) were elevated in all treated plot types (MCA, MDA and MDB) compared with the non- manipulated baseline plots (semistable, stabilized), but this was statistically significant only in MDA plots compared to semistable plots (for p-values, see Table 14). N animals with N animals with % animals with injured tails intact tails injured tails Active 25 11 69.44 Semistable 71 49 59.17 Stabilized 94 60 61.04 MCA 24 9 72.73 MDA 39 14 73.59 MDB 42 23 64.62

Table 14: Tail injury in S. sepsoides statistical significance (p-values), for multiple comparisons of proportional incidence (Fisher Exact tests conducted on the counts which appear in Table 13). Semistable Stabilized MCA MDA MDB Active 0.086 0.100 0.487 0.172 0.156 Semistable X 0.094 0.110 0.049 0.286 Stabilized X 0.074 0.068 0.366 MCA X 0.196 0.133 MDA X 0.093

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Ratio Body Index - Sphenops sepsoides 0.023

0.021 / bodylength 0.3

0.019 active (11) semistable stabilized MCA (9) MDA (14) MDB (23) body mass body mass (49) (60)

Figure 35: Body condition index of S. sepsoides across plot types, compared for animals captured in pitfall traps (calculated only for animals with intact tails). Sample size per plot type is parenthesized. Body condition index seemingly increased in all treated plot types (MCA, MDA and MDB) compared with the non-manipulated baseline plots (semistable, stabilized), but this was not statistically significant (p-values for multiple comparisons summarized in Table 15).

Table 15: Body condition index of S. sepsoides statistical significance (p-values), for multiple comparisons of animals captured in pitfall traps (Student's t tests conducted on the data displayed in Figure 35). Semistable Stabilized MCA MDA MDB Active 0.168 0.008 0.422 0.145 0.031 Semistable X 0.035 0.730 0.782 0.258 Stabilized X 0.115 0.192 0.284 MCA X 0.560 0.282 MDA X 0.538

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a b

Figure 36: Examples of S. sepsoides specimens, in situ, with intact (a) or broken (b, c) tails. These lizards readily burrow (c) and move underneath sand surface. Photo: Boaz Shacham, May 2008.

In S. sthenodactylus tail injury incidence was found to be relatively low, and ranged from 6.4% in the semistable plots to 27.3% in the MDB plots. Among the non- manipulated plots, tail injury rate was highest in the active plots, lowest in the semistable plots and intermediate in the stabilized plots, but none of the differences were statistically significant. Among the manipulated plots, it appears as if tail injury rate only slightly increases in the MCA plots but spikes to record highs of 20% and 27.3% in MDA plots and MDB plots, respectively. However, these differences were also not statistically significant. The numbers of animals with or without tail injury and the calculated proportion of injured animals are summarized in Table 16 and displayed in Figure 37.

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Significance levels (p-values) of multiple comparisons between the plot types are given in Table 17. Ratio body index (BI) was calculated as described for S. sepsoides and compared for animals with intact (non-injured) tails among all plot types. In non- manipulated plots, BI was highest in active plots and was nearly identical in semistable and stabilized plots, no significant differences were detected between plot types. In MCA plots, BI slightly increased compared to their baseline in semistable plots, while both MDA and MDB plots remained practically identical to their baseline in stabilized plots, again no significant differences were detected between plot types. The average BI indices for all plot types are shown in Figure 38, significance levels (p-values) of multiple comparisons between the plot types are given in Table 18. Summarizing results for S. sthenodactylus, the trends observed are a subtle increase of BI in the MCA plots, and a nearly twofold increase of tail injury rate in MDA and MDB plots. An exemplar of this species is shown in Figure 39.

intact % injured tails of Stenodactylus sthenodactylus injured 100%

80%

60%

40%

20%

0% active (12) semistable stabilized MCA (23) MDA (20) MDB (22) (63) (57)

Figure 37: Tail injury rate in S. sthenodactylus. Proportion of S. sthenodactylus captured in pitfall traps with intact tails versus animals with injured (broken or regenerated) tails. Total sample size per plot type is parenthesized. Percent injured tails was elevated in all treated plot types (MCA, MDA and MDB) compared with the non- manipulated baseline plots (semistable, stabilized), but not statistically significant.

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Table 16: Tail injury rate in S. sthenodactylus. Accumulated numbers of S. sthenodactylus captured in pitfall traps divided into animals with intact tails and animals with injured (broken or regenerated) tails. Proportion of animals with injured tails (in percent) were elevated in all treated plot types (MCA, MDA and MDB) compared with the non-manipulated baseline plots (semistable, stabilized), but this was statistically significant only in MDB plots compared to semistable plots (for p-values, see Table 17). N animals with N animals with % animals with injured tails intact tails injured tails Active 2 10 16.67 Semistable 4 59 6.45 Stabilized 7 50 12.28 MCA 2 21 8.70 MDA 4 16 20.00 MDB 6 16 27.27

Table 17: Tail injury in S. sthenodactylus statistical significance (p-values), for multiple comparisons of proportional incidence of tail injury in animals captured in pitfall traps (Fisher Exact tests conducted on the counts which appear in Table 16). Semistable Stabilized MCA MDA MDB Active 0.195 0.308 0.319 0.353 0.271 Semistable X 0.136 0.512 0.073 0.014 Stabilized X 0.288 0.192 0.075 MCA X 0.266 0.107 MDA X 0.246

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Ratio Body Index - Stenodactylus sthenodactylus

0.03 / body length / body 0.3

0.02 body mass body active (10) semistable stabilized MCA (21) MDA (16) MDB (16) (59) (50)

Figure 38: Body condition index of S. sthenodactylus across plot types, compared for animals captured in pitfall traps (calculated only for animals with intact tails). Sample size per plot type is parenthesized. Body condition index slightly increased the MCA plots but remained unchanged in MDA and MDB plots compared with the non- manipulated baseline plots (semistable, stabilized). No statistically significant differences were found in any of the multiple comparisons (p-values summarized in Table 18).

Table 18: Body condition index of S. sthenodactylus statistical significance (p-values), for multiple comparisons of animals captured in pitfall traps (Student's t tests conducted on the data displayed in Figure 38). Semistable Stabilized MCA MDA MDB Active 0.242 0.233 0.609 0.277 0.245 Semistable X 0.908 0.129 0.842 0.971 Stabilized X 0.130 0.785 0.884 MCA X 0.222 0.132 MDA X 0.861

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Figure 39: Example of S. sthenodactylus specimen, male, October 2006. Photo: Boaz Shacham.

Response of Acanthodactylus to Dune Management

As presented in the previous chapter, the two diurnal lacertid lizard species of the genus Acanthodactylus were found to be good indicators of plot type (vegetation cover category). The species A. scutellatus dominates the active dunes, while A. schreiberi dominates the stabilized dunes, both sharing to some extent the semistable dunes. Comparison of results from the diurnal lizard activity transects in the manipulated plots to those conducted in the non-manipulated plots are presented here.

The accumulated numbers of lizards of each species per plot type are summarized in Table 19. These data comprised the "observed" table for analysis using Chi2 tests. The frequencies observed were highly significant when all six plot type categories are included (χ=1022.77, df=5, p-value<0.001). The average number of lizards observed per transect at each of the plot types is summarized in Table 20 and displayed in Figure 40.

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Significance levels of these averages are summarized in Tables 21 and 22. The responses of Acanthodactylus species observed in the manipulated plot types are as follows:

Effects in MCA plots – Frequencies of the Acanthodactylus species were found to be significantly different in the MCA plots compared to their baseline plot type, semistable (χ=8.17, df=1, p-value=0.004), and also when compared to their targeted plot type, active (χ=282.19, df=1, p-value<0.001). Both species showed an increase in average number observed per transect compared to the semistable baseline, significantly in A. scutellatus but non-significant in A. schreiberi. Compared to the target plot type, active sand, the number of A. scutellatus is still lower in MCA plots, while the number of A. schreiberi remains much higher in MCA plots, both significantly so.

Effects in MDA plots – Frequencies of the Acanthodactylus species were not significantly different in the MDA plots compared to their baseline plot type, stabilized (χ=1.47, df=1, p-value>0.05), but were significantly different compared to their targeted plot type, active (χ=497.64, df=1, p-value<0.001). There was slight decrease in average number of A. schreiberi observed per transect compared to the stabilized baseline, and A. scutellatus was completely absent, both results not significantly different from the stabilized plots. Compared to the target plot type, active sand, the MDA plots maintain a virtual mirror image regarding the frequencies of Acanthodactylus lizards as seen in stabilized plots, for both species significantly different from that in active plots.

Effects in MDB plots – Frequencies of the Acanthodactylus species were not significantly different in the MDB plots compared to their baseline plot type, stabilized (χ=1.47, df=1, p-value>0.05), but were significantly different compared to their targeted plot type, semistable (χ=221.85, df=1, p-value<0.001). There was slight decrease in average number of A. schreiberi observed per transect compared to the stabilized baseline, and A. scutellatus was completely absent, both results not significantly different from the stabilized plots. Compared to the target plot type, semistable sand, the MDB plots maintain significantly higher numbers of A. schreiberi and completely (and significantly) lack A. scutellatus which would be expected to be present. Similarly to MDA plots, the

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MDB plots de facto preserve the frequencies of Acanthodactylus lizards as seen in stabilized plots.

Table 19: Total numbers of Acanthodactylus lizards observed (in the lizard transects), used as the basis for "observed" data for Chi2 test. Plot type N transects A. scutellatus A. schreiberi Total Active 57 498 2 500 Semistable 91 191 87 278 Stabilized 74 3 253 256 MCA 28 81 67 148 MDA 50 0 125 125 MDB 44 0 124 124 Total -- 773 658 1431

Acanthodactylus in lizard transects

16 A. scutellatus 14 A. schreiberi 12 10 8 6 4 2 0

B ive MCA MDA MD act average N lizards observed lizards N average abilized st semistable

Figure 40: Average numbers of Acanthodactylus lizards observed (in lizard activity transects) on the various plot types (data summarized in Table 20, significance of comparisons in Tables 21 & 22).

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Table 20: Average numbers of Acanthodactylus lizards observed (in the lizard transects) in the different plot types (SD = standard deviations). Significance levels (p- values) of multiple comparisons are given in Tables 21 & 22. Plot type N transects A. scutellatus (±SD) A. schreiberi (±SD) Active 57 8.74 ± 6.545 0.03 ± 0.254 Semistable 91 2.10 ± 2.684 0.96 ± 1.639 Stabilized 74 0.04 ± 0.349 3.42 ± 2.575 MCA 28 2.89 ± 3.675 2.39 ± 3.370 MDA 50 0.00 ± 0.000 2.50 ± 1.821 MDB 44 0.00 ± 0.000 2.82 ± 2.705

Table 21: A. scutellatus significance levels (p-values), for multiple comparisons of averages observed in lizard transects in the different plot types summarized in Table 20 (ANOVA, Tukey post-hoc tests). Semistable Stabilized MCA MDA MDB Active 0.000 0.000 0.000 0.000 0.000 Semistable X 0.001 0.865 0.003 0.006 Stabilized X 0.001 1.000 1.000 MCA X 0.002 0.003

Table 22: A. schreiberi significance levels (p-values), for multiple comparisons of averages observed in lizard transects in the different plot types summarized in Table 20 (ANOVA, Tukey post-hoc tests). Semistable Stabilized MCA MDA MDB Active 0.084 0.000 0.000 0.000 0.000 Semistable X 0.000 0.021 0.001 0.000 Stabilized X 0.240 0.163 0.663 MCA X 1.000 0.960

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To graphically compare Acanthodactylus species responses to the manipulation treatments with the pre-manipulation baseline, data from manipulated plots were added to the incidence/abundance phase plane (Hawlena & Bouskila, 2006) presented in the previous chapter (Figure 23). The graph plots incidence levels (proportion of samples, from total dataset, in which given species was present) against abundance levels (logarithmic transformation of the average observed specimens, per sample, of a given species) and is shown in Figure 41. The effects seen in this graph include:

Effects in MCA plots – Abundance of A. scutellatus slightly increased in the MCA plots compared to the semistable plot baseline ("BC" in the figure), while incidence slightly decreased. Both abundance and incidence of A. schreiberi showed an increase in MCA compared to semistable plots. In both species these trends do not show high similarity to the situation in the target dunes, active plots ("A").

Effects in MDA plots – Incidence and abundance levels of A. schreiberi show small decrease in MDA plots compared to the baseline in stabilized plots, while A. scutellatus remained completely absent from the MDA plots, unchanged from the situation in the stabilized plots. In spite of the manipulation treatment, the MDA plots retain what seems to be a mirror image exactly opposite to the Acanthodactylus levels seen in the target active plots ("A").

Effects in MDB plots – Incidence level of A. schreiberi slightly decreased and its abundance level was virtually unchanged while A. scutellatus remained completely absent in MDB plots, compared to the baseline of these species in stabilized plots. In spite of the manipulation treatment, the MDB plots retain profoundly different incidence and abundance levels of both Acanthodactylus seen in the target semistable plots ("BC").

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Incidence/Abundance of Acanthodactylus lizards

1.5

A 1

MCA MDB 0.5 MCA D BC BC MDA 0

0 0.2 0.4 0.6 0.8 1 -0.5 logAbundance -1 D

-1.5 A A. schreiberi M DB MDA A. scutellatus -2 Incidence (proportion)

Plot symbols: active (A); semistable (BC); Stabilized (D); MCA; + MDA; X MDB

Figure 41: Incidence/abundance phase plane of Acanthodactylus lizards observed (in lizard activity transects) on the various plot types. Arrows show the trajectories of change from baseline state in the manipulated plots (from stabilized "D" to MDA, MDB; from semistable "BC" to MCA), for each of the two species, A. scutellatus (red arrows) and A. schreiberi (black arrows).

Exemplars of the two Acanthodactylus species are shown in Figures 42 & 43.

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Figure 42: Exemplars of A. scutellatus, mating, the male in the foreground, April 2006. Photo: Boaz Shacham.

Figure 43: Exemplars of A. schreiberi, mating, the male on the left-hand side, August 2006. Photo: Boaz Shacham.

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Discussion and conclusions

Reptile Assemblages at Nizzanim Sands

The first and most basic aim of my study was to describe the reptile assemblages in Nizzanim sands. The herpetofaunal species assemblages in Nizzanim sands show strong associations with quantitative and qualitative attributes of perennial vegetation cover on the dunes. In general, there is an increase in reptile abundance (as seen in pitfall trapping), activity levels (as seen in track transects) and overall species richness along the gradient of increasing perennial vegetation. These associations support my predictions – dune stabilization level (perennial vegetation density) affects reptile assemblages, the active (low vegetation density) dunes present lower overall reptile diversity and abundance coupled with a higher proportion of desert specialist species, while stabilized (high vegetation density) dunes present higher overall reptile diversity and abundance coupled with a higher proportion of generalist species.

Naturally, different reptile species showed different associations with dune stabilization level. For instance, the diurnal lizard Acanthodactylus scutellatus has an inverse relationship with perennial vegetation cover levels. Moreover, some species show higher affinity, or elevated activity, in the semistable dunes, where the vegetation cover is between the extremes of low cover on the active dunes and high cover on the stabilized dunes. For instance, the lizard Stenodactylus sthenodactylus and the snakes Lytorhynchus diadema and Psammophis schokari show peaks in incidence proportion at the semistable dunes (see Table 3); all three are desert specialist species. Average desert specialist species richness significantly peaked in the semistable dunes, this accords partially with my hypothesis and predictions – that reptile diversity will show a hump-shaped relationship with productivity (perennial vegetation density = stabilization). Such a relationship fits the Intermediate Disturbance Hypothesis (IDH; Grime, 1973; Horn, 1975; Connell, 1978), which stipulates that maximal local species diversity is to be expected at intermediate levels of ecological disturbance. According to IDH, at low level (infrequent or low intensity) ecological disturbance the highly competitive species will dominate the ecosystem, perhaps to the extent of driving less competitive species to local

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extinction; while at high level (frequent or high intensity) disturbance only species adapted to high levels of disturbance (or able to quickly colonize habitats immediately after disturbance occurs) will prevail. At intermediate disturbance levels, species of both "types" ("competitors" and "survivors") may co-exist, thus potentially maximizing species richness (see Figure 44).

High levels of disturbance Low levels of reduce diversity disturbance allow competition to reduce diversity

Diversity is expected to be highest at intermediate disturbance levels

SPECIES DIVERSITY SPECIES DIVERSITY Active Semistable Stabilized DUNE TYPE Frequent/high Infrequent/low intensity intensity DISTURBANCE

Figure 44: Hypothesized relationship of species diversity with dune stabilization, according to the Intermediate Disturbance Hypothesis (IDH; Grime, 1973; Horn, 1975; Connell, 1978; figure follows: Molles, 2009).

The term ecological disturbance is used here under the broad definition "any relatively discrete event in time that disrupts ecosystem, community, or population structure and changes resources, substrate availability, or the physical environment" (White & Pickett, 1985). Common examples for ecological disturbance studied and reported in the literature include periodic fires (e.g., Collins et al., 1995) and flooding regimes in streams (e.g., Townsend et al., 1997). I assume that sand mobility and windstorms constitute "disturbance" in the Nizzanim sands ecosystem (e.g., Perry, 2008), these abiotic factors should decrease with increased dune stability (dune types

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superimposed on x axis in Figure 44), while biotic factors such as competition are expected to increase.

With the exception of the desert specialist species richness, my data do not support a strong association of the reptile assemblages at Nizzanim with IDH, and I speculate that this is due to the strong additive effect of generalist reptile species to the assemblages with increased dune stabilization. It is possible that the extant plant cover in the stabilized dunes that I sampled is not dense enough to fit the theory. Alternative hypotheses may include positive or negative relationships between species diversity and productivity, as reviewed by Mittelbach et al (2001). My previous experience with reptiles in coastal sands led me to believe that the hump-shaped relationship is more plausible, and is supported by observational data collected in other sites, but not within the study plots described in this study (Shacham, unpublished).

Since qualitative factors of the vegetation, such as dominant species and life forms, are highly auto-correlated with total cover (percent), it is difficult to tease them apart. Surely, at least in some of the species, there are probably associations with certain life forms or even specific perennial plant species, perhaps even relationships akin with co- evolution. Such could be the case with the most common perennial shrub in Nizzanim sands, Artemisia monosperma: the above ground architecture and root system of this shrub seem to host much reptile activity, including burrows of lizards.

When additional species richness indices are used besides total species richness, the picture becomes more complex but gains sharper focus. Desert specialist species richness (accumulated species N) steadily declines along the vegetation cover gradient, but since the range is narrow (from 9 species in active dunes to 7 species in stabilized dunes), these species cannot explain the general increase in total species richness observed with the rise in dune stability. This increase in total species richness is evidently due to a steady rise in presence of generalist reptile species along the vegetation cover gradient. A somewhat simplistic, but efficient, index to measure these trends is the proportion (percent) of desert specialist species within total species richness. There is a steady positive correlation of desert specialist proportion with increased vegetation cover, showing that as the dunes go

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through the successive process of stabilization the reptile fauna also goes through successive changes, gradually becoming dominated by generalist species. Similar trends have been seen in data regarding rodents (Shacham & Bouskila, 2007) and some of the arthropod taxa (Ramot, 2007), collected by the teams studying these groups in Nizzanim sands. These findings support my predictions – that reptile assemblages and specific species, especially those with high affinity to extreme dune types (active or stabilized) will prove good indicators for dune stabilization level. As has been mentioned, the proportion or ratio between desert specialist species and generalist species may be used as a proxy for indicating dune stabilization. The best candidates for species-level indicators of dune stabilization are the two Acanthodactylus species as described in the results, this issue is discussed in depth in a later section of this chapter.

The gradual succession of dunes from active sand to stabilized sand involves generalist species encroachment. Ultimately the habitat becomes inhospitable to the desert specialist reptiles and they become locally extinct. In this project I did not sample extremely stabilized sandy habitats, such as interdune areas, but my anecdotal observations as well as those of many of my colleagues suggest that this indeed is the ultimate product of sand stabilization. On the other hand, many of the desert specialist species tend to concentrate much of their activity in the semistable and stabilized dunes, contrary to conventional wisdom regarding their presumed preferences. The mounting evidence accumulated on reptile assemblages in the Nizzanim sands verifies the initial assumption that for effective conservation of the reptile fauna in coastal sands, diversity of different vegetation cover levels must be maintained along a wide range. This principle holds true for the findings of the studies conducted at Nizzanim on other taxa, including annual vegetation (Perry, 2008) and arthropods (Ramot, 2007). The importance of maintaining habitat diversity, for conservation of diverse reptile fauna in sandy habitat landscapes, has been demonstrated in other geographic areas, e.g. Coachella Valley, California (Barrows & Allen, 2009).

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Reptile Assemblage Response to Manipulation at Nizzanim Sands

Since the dynamics of sand dune stabilization in the coastal dunes of Israel are unidirectional, active management of the dunes is required to artificially increase the amount of active and semistable dunes while decreasing the amount of stabilized dunes. The second main aim of my study was assessing the herpetofaunal responses to the management actions at Nizzanim. I monitored and compared reptile assemblage responses to the three different levels of dune management (vegetation manipulation regimes) included in the Nizzanim project: semistable sands manipulated to active sands vegetation cover (MCA), stabilized sands manipulated to active sands vegetation cover (MDA) and stabilized sands manipulated to semistable sands vegetation cover (MDB). I had predicted that dune manipulation will have immediate and prolonged effects on reptile assemblages; all three treatments support this prediction regarding immediate effects (first season post-manipulation), and the MCA treatment shows also a more prolonged effect. The strongest effects suggesting shifts towards assemblages at target dunes were observed in the MCA treatment, the weakest were observed in the MDA treatment, while weak but intermediate effects were observed in the MDB treatment. These results suggest that intervention and manipulation at an earlier stage of stabilization may fare better than at later, more stabilized stages. They also suggest that when intervention is made in the later stages, more radical and aggressive treatment fares better than moderate treatment. This concurs with my prediction – that different manipulation regimes will produce different effects on reptile assemblages, and that regimes with higher contrast between pre- and post-manipulation vegetation levels produces stronger effects on assemblages. As banal and expected as these results and interpretations may seem, they have rarely been empirically tested in the field, and never before on such a large scale in a Mediterranean coastal sand habitat. It is important to note that most of the studies published in the literature to date report manipulations of sand dunes in the opposite direction – aimed at increasing dune stability, for instance in New Zealand (e.g. Bergin & Kimberly, 1999) and Alaska (e.g. Wright, 2007). This is in direct contrast to the management technique employed in the Nizzanim project.

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The trajectories of the management effects through time show differences in observed responses under the different treatment regimes. Only in the treated semistable dunes (MCA treatment), the responses seemed to create assemblages similar to those of the targeted active dunes, responses that remained evident even three years after the manipulation actions. In contrast, the treated stabilized dunes (MDA and MDB treatments) showed an initial response towards the targeted trajectory in the first year after manipulation, but then seemed to revert or rebound towards the pre-manipulation baseline assemblages. There are several potential explanations for the observed results, the most plausible of these being, in order of decreasing likelihood: 1. Some species of reptiles may be responding at a slower pace to the management actions, or may be experiencing difficulties in colonizing the treated dunes, thus affecting the observed trajectory. 2. The perennial vegetation is regenerating or becoming reestablished, thus gradually erasing the initial response seen during the first post-treatment season. 3. The time span of my study is too short for detection of the response of the stabilized dunes; in many systems there exists a "hysteresis of repair" which takes on a painstakingly slow pace of recovery for rehabilitated habitats (Lake, 2001). 4. For some (or all) of the reptile species involved in the assemblages, the mechanism chosen for managing the dunes, partial removal of perennial vegetation, is too simplistic. Perhaps our efforts to reconstruct the active or semistable dune habitats lack some factor or factors that may be critical for affecting a response from these species.

Naturally, the responses seen in the various treatment regimes are probably affected by a combination of factors, including those mentioned above. If I wish to speculate on possible extrapolation of the trajectories into the future, according to the first explanation there will be improvement over time (years, perhaps decades) in the similarity of the assemblages in treated dunes compared to the target dune types. According to the second explanation, no change will be seen over time unless further management actions (unknown at this time) are taken. According to the third explanation, there will not be a change in the trajectory towards the target dune types until successful colonization or rehabilitation occurs in certain species, perhaps necessitating active management if

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spontaneous response is lacking. According to the fourth explanation, the trajectory will change again towards the target dune types only if and when partial vegetation removal is repeated.

On of my predictions was that vegetation removal will initialize colonization by desert specialist species on the manipulated dunes. In fact, the majority of the desert specialist species were already present on the manipulated dunes before the manipulation, thus the majority of effects observed post-manipulation were abundance levels or incidence proportion of desert specialist on these dunes. With the exception of one prominent desert specialist: Acanthodactylus scutellatus. All evidence points to the lack of colonization and establishment of populations of the lizard A. scutellatus in the treated stabilized dunes as the most prominent factor differentiating their response from that seen in the treated semistable dunes. Examination of the spatial orientation of the treated stabilized dunes reveals that habitat structure constraints are hindering colonization by these lizards. The stabilized dunes are situated in an area which is flanked by habitats inhospitable to A. scutellatus from all sides: heavy sediments, agricultural fields and groves to the east and to the north; the floodplain heavy sediments and banks of Wadi Evtah to the south and southwest; patches of relict Acacia albida savanna to the southwest; remnants of traditional agriculture (mainly Ficus sycamora and other fruit trees), the crest of a kurkar sandstone ridge and a 3-meter wide dirt road to the west. Visual searches conducted in the aforementioned habitats on various occasions yielded zero observations of A. scutellatus lizards, while dozens of potential competitors, such as A. schreiberi, and generalist (Mediterranean) lizard species, such as Mabuya vittata, were observed. To the best of my knowledge, no A. scutellatus populations exist east of the study site in the latitude of Nizzanim. In further sample surveys, conducted west of the dirt road flanking the described environs, A. scutellatus were indeed observed. It seems as if the treated stabilized dunes constitute a "sink" habitat for A. scutellatus which resides within an area disjunctive of the potential "source" populations of this species. It is not completely inconceivable that individual A. scutellatus may eventually reach the treated dunes, but the probability of establishment of a viable population or populations is extremely slim. With the exception of Varanus griseus, which was extremely rare in this project and A. scutellatus, none of the other desert specialist species were absent from the

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treated and untreated (control) stabilized dunes. The best way to assess whether the lack (or lag) in colonization of the treated stabilized dunes by A. scutellatus is due to habitat constraints, not unsuitable habitat at the treated dunes, is to artificially colonize these dunes by relocating lizards from a viable source population. This allows to test whether indeed the lack of support seen for my prediction was a consequence of the aforementioned physical barriers surrounding the treated dunes.

Late in the 2007 season, an opportunity arose to conduct a preliminary experimental relocation of A. scutellatus lizards. This effort was made in tandem with a similar relocation experiment of Gerbillus pyramidum, a sand dwelling desert specialist rodent which also failed to spontaneously colonize the treated stabilized dunes. Lizards and gerbils of these two species were captured in active dunes near Nizzanim beach, in an area destined to undergo development for a tourist resort. Trapping and relocation were conducted under permit and in coordination with the Nature & Parks Authority, as required by law and in adherence with the policy through out all the fieldwork in my project. A total of 49 A. scutellatus lizards (the majority juveniles) were captured, measured, marked for identification and relocated at three of the six treated stabilized dunes, in late October 2007. During the following season (early spring 2008), only on two occasions relocated lizards were observed, but unfortunately they were not captured and thus could not be individually identified. No relocated lizards have been observed since spring 2008, which leads me to conclude that relocated A. scutellatus did not establish populations in the treated dunes. This does not prove that successful relocation is impossible, merely that our preliminary experiment failed. Many factors may have contributed to such failure, among them [a] the relocation may have been at a sub-optimal seasonal timing, [b] the relocated lizards may have been too young and thus prone to instinctively scattered spatially and left the treated plots or [c] the number of individuals relocated to each plot (between 16-17) may have been too small. Given the high mortality expected for juvenile lacertids even in their optimal habitats, I have every reason to believe all 49 lizards eventually perished. If in the future an attempt to establish viable populations of A. scutellatus at the treated stabilized dunes will be made, more complicated factors should be considered in order to improve the chances of success. From what has been published on successful relocation or recolonization of lizards in the

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literature (e.g. Brisson et al., 2003), we know that it is important to [a] maintain the desired state in the rehabilitated habitat, [b] preserve connectivity between habitat patches to guarantee gene flow within the metapopulation, and in some cases or patches [c] repeat relocation of supplemental individuals several times until the relocated population stabilizes. This means that perennial vegetation regeneration and proliferation must be curbed, corridors of open sand patches must be created to connect the treated dunes with the "source" populations of A. scutellatus and additional lizards must be repeatedly released (as needed). All these actions must be meticulously documented and monitored. In the Eurasian species Lacerta agilis, for instance, three annual releases of 50 juveniles (both sexes) have been recommended for establishing viable populations in England (Moulton & Corbet, 1999). Based on modeling predictions, Berglind (2004) recommends for L. agilis metapopulation establishment in central Sweden to release animals in one selected habitat patch if juveniles are limited, but to divide them among several patches if juveniles are abundant.

In addition to responses of reptile species assemblages to the manipulation treatments, I examined possible physical responses of individuals of some common species. By manipulating the perennial vegetation cover level, we altered the habitats in such a manner that may have changed the perceived or actual risk of predation on the reptiles. Tail loss incidence within lizard populations may indicate the level of predation pressures to which the lizards are subjected (Arnold, 1984). The most common lizard trapped in my pitfalls, the scincid Sphenops sepsoides, had higher tail loss incidence in the active dunes, where presumably visual predators (e.g. red fox, stone curlew) locate the lizards with greater ease since shrub density is low and there are less refugia to hide beneath or behind. In all treated dune types (MCA, MDA and MDB), tail loss incidence in this S. sepsoides was elevated compared to the baseline dunes types, suggesting that indeed predation pressures increased. In the second most common lizard trapped, the gekkonid Stenodactylus sthenodactylus, tail loss incidence was also higher in the active dunes. In the MCA treated dunes tail loss incidence in S. sthenodactylus was apparently unchanged, but in the MDA and MDB dunes levels practically doubled. Most of these changes were seen as trends, but I believe that if I had larger sample sizes they would be statistically significant. A sharp contrast exists between the two species described here,

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with S. sepsoides showing on average three times higher overall tail loss incidence compared to S. sthenodactylus. This suggests that the latter may have evolved to avoid tail injury, while the former may have evolved to survive tail injury, as has been described by Seligmann et al. (2003), and accords with differences in escape behavior I have observed in these species. Such differences between species may also suggest differences in specific predators that prey on them (Seligmann et al., 1996). However, it is worth mentioning that the ecological interpretation of tail loss in lizards has been and still is debated in the literature (e.g., Schoener & Schoener, 1980).

Risk of predation is not, obviously, the only factor that is affected by perennial vegetation cover. Higher perennial vegetation cover entails, by definition, higher biomass levels, potentially feeding higher numbers of herbivore and granivore species, and thus potentially boosting predators. In spite of the fact that my pitfall trapping results found higher densities of both S. sepsoides and S. sthenodactylus with increased perennial vegetation cover, results from the arthropod study conducted at the same study sites found no significant correlations of species richness or abundance of arthropods with increased vegetation (Ramot, 2007). This indicates that although the lizards apparently find better refuge from their predators as vegetation cover increases, they do not necessarily find richer food resources (these lizard species prey on arthropods). Comparison of the body condition index (BI) of lizards among the dune types showed that BI was highest at active dunes in both S. sepsoides and S. sthenodactylus. The BI of S. sepsoides increased in all treatment regimes (highest increase in MCA treatment), while BI of S. sthenodactylus increased in MCA treatment dunes but remained unchanged in the other treatment regimes. These observed trends regarding BI lead to the conclusion that the higher abundance of both lizard species in semistable and stabilized dunes probably comes at a cost of higher inter-specific and intra-specific competition for resources. Other studies have shown that experimental increase of predation risk results in decreased growth rates in mice (Arthur et al., 2004) and decreased BI in some lizard species (Hawlena & Bouskila, 2006). The fact that S. sepsoides and S. sthenodactylus in my study fare better in what superficially seems to be the poorest (resource-wise) and most dangerous (predation-wise) habitat may seem counter-intuitive at first, but these species have evolved as desert specialists and are well adapted to the active sand dunes. I

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hypothesize that a trade-off exists between predation risks, reflected in tail injury frequencies of the lizards, and competition for resources, evident in the BI of lizards (see Figure 45). My data lack the resolution needed to tease apart the mechanisms interplaying in this proposed trade-off: predation pressure (actual or perceived), inter-specific and intra-specific competition for resources. But these results have opened new opportunities for further study of this system, and show promise as potential future indicators for dune stability level and dune management effects on reptiles.

Predation pressures resourcesfor Competition Active Semistable Stabilized DUNE TYPE

High predation pressure Low

Low resource competition High Figure 45: Hypothesized trade-off between predation and competition; predation pressures or risks (red solid line) may be traded off with competition for resources (blue dashed line) along the gradient of increased dune stabilization.

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Implications for Management and Monitoring

The third main aim of my study was to provide methodological guidelines for monitoring herpetofaunal responses to sand dune management programs. These guidelines include choosing appropriate indicator reptile species, comparing the efficiency of several sampling methods and implementing an integrative approach for combining the data from these methods. I present and discuss here the potential application of the guidelines at Nizzanim and elsewhere.

The most obvious choice for reptilian ecological indicators at Nizzanim are the two Acanthodactylus species, with each of them showing high affinity and fidelity to their preferred habitat types: A. scutellatus dominates the active dunes, while A. schreiberi reigns over the stabilized dunes. Both species share to some extent the semistable dunes, with anecdotal evidence (Shacham, unpublished) showing that even then they do not share the same microhabitats – there is some niche segregation, with A. scutellatus mainly on the slipface of the dune and A. schreiberi mainly on the dune windface. Previous work has shown that these species co-exist through differential resource allocation (Avital, 1981) when sharing the same dunes. Both species responded to the management in the MCA treatment dunes, with an increase of A. scutellatus and a decrease of A. schreiberi both in absolute as well as proportional numbers. Due to the spatial constraints discussed earlier, A. scutellatus failed to establish populations in the MDA and MDB treatment dunes. These lizards are excellent indicators of both substrate (sand mobility) and perennial vegetation cover level in untreated dunes, and are potential indicators for management effects as long as the treated habitat patches are not disconnected from active sand dunes. These two species fulfill the criteria listed earlier (see Introduction chapter) for choosing indicators, and are the best potential indicator species for quick and reliable assessment of the reptile assemblages in Nizzanim sands. Since they are diurnal and abundant, it is easy to spot them and no illumination or optical devices (e.g. night vision gear) are needed to observe them for transect census. Our data comply with previous studies showing these lizards are active nearly year-round (e.g. – Avital, 1981). The disadvantage of these transects is that novice observers may find it difficult to describe demographic details such as sex and age group, but on the other hand

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they should identify the lizard species with reasonable ease (after simple training and practice with experienced observers).

In light of the results obtained regarding tail injury frequency and lizard body condition from the nocturnal species, it would be very informative to consider in the future pitfall trapping during the daytime, thus obtaining such data on Acanthodactylus. I could not afford doing such sampling, unfortunately, during my study, due to time constraints – I was much too busy with other tasks to have time to patrol the dunes checking the pitfalls during the day. Since we have the pitfall arrays in situ year round (but filled in with sand when we are not sampling), it is possible to conduct trapping sessions for Acanthodactylus on separate dates from the nocturnal trapping sessions, or to have a separate team working the pitfalls during daytime. I strongly recommend realizing this option for a more in-depth study of these lizards at Nizzanim.

The same is true for the two most common lizard species caught in the pitfall trapping: S. sepsoides and S. sthenodactylus. The trends I have found regarding tail injury frequencies and BI along the vegetation cover gradient, and in response to the management, warrant a more in-depth study of these animals at Nizzanim, since larger sample sizes will help tease apart random effects from significant ones. These physical effects may ultimately prove to be as important, if not more so, for understanding response to management actions than the effects observed in reptile species assemblies. This may be achieved by adopting a more intensive trapping regime, for example, instead of sampling each study plot twice a year (two nights during each sampling session), sampling five or six times a year (during optimal months for these species' activity). Another option is to double the number of trapping nights per study plot in each session. In any case, I recommend increasing the nocturnal trapping effort.

Nearly all the species observed in this study exhibited seasonal variation, either in abundance or activity levels or both. This is obviously expected in reptiles, as in all vertebrates, and is mostly derived from species life history traits, demographic processes and seasonal climatic factors. Given the nature of seasonality in the coastal dunes of Israel, the best seasons in which to collect data on reptiles are spring (March-May) and

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autumn (September-October). Albeit Mediterranean precipitation levels (at Nizzanim, circa 470 mm per annum), rainfall is generally unpredictable thus curbing any advance logistical planning, and in any case, it is useless to sample sand dwelling reptiles once the rainy season begins, due to the fact that many of the species are dormant when the sand is moist (particularly the burrowing species, S. sepsoides and Lytorhynchus diadema). During the summer there is increased activity of most nocturnal species, most notably snakes, but high temperatures during the day greatly reduce the time available for much of our sampling activity, especially the diurnal lizard transects. During spring there is much activity of almost all reptile species busy with reproductive efforts and attempting to regain calories lost during lowered or halted activity in the winter months, and it is a good season for assessing survival of juveniles to subadult stages. On the other hand, during autumn there is again much activity in most species building up fat reserves for the winter months, and it is an excellent season for assessing reproductive success as most of the clutches have hatched or been born. Thus, if funding or logistics limit the sampling of the project to a single season, the decision whether to sample in spring or in autumn depends on which aspects of reptile ecology are more important or informative for monitoring purposes. From my experience, the best option is to aim for spring, since there is a higher amount of resources in the ecosystem with the annual plants in full bloom, arthropod activity high and higher probability of finding a larger proportion of species. Of course, the somewhat erratic nature of the climate during both spring and autumn may create situations in which sampling is hampered or even ruined. For instance, during the April 2006 sampling session at Nizzanim, there were freak rains for two days, physically erasing all of our track transects and eliminating most reptile activity, especially of the nocturnal species, thus we ended up with null data for the plots sampled during those two days. I recommend optimizing and maximizing the breadth and depth of data collected by sampling during spring and autumn in the coastal dunes, with preference to late spring if sampling is limited to one season.

Besides considering seasonal variation in abundance and activity levels of the reptile species, any sand dune reptile monitoring work must take into account potential methodological artifacts and biases of the sampling methods. While pitfall trapping data and track transects data were recorded at dawn (minimizing stress to trapped animals and

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wind erosion of tracks, respectively), the lizard activity transects could not be scheduled in advance for a specific time; only if the sky was not overcast, surface temperatures were above certain minima and lizard activity had actually begun did we initiate these transects. When extreme conditions prevented or suppressed lizard activity (for instance, heat wave 'hamsin' conditions), we aborted completely the lizard transects sampling effort. We were generally surprised by the fact that S. sepsoides activity in the track transects was highest in the stabilized dunes, since we expected this extreme sand specialist to prefer the active dunes. Initially we believed this may have been an artifact of the sampling method, since the track transects are erased in the gaps between the shrubs, and perhaps the high shrub density on stabilized dunes channels S. sepsoides activity to these same "corridors" coinciding with our transects; on active dunes the skinks have more open patches and thus their activity misses our transects with higher probability. But comparison to the pitfall trapping data proves that this is probably not the case: S. sepsoides trapped increase with increased perennial vegetation level, peaking at the stabilized dunes. A similar comparison between sampling methods in the gecko S. sthenodactylus gives contradictory results: while activity levels on track transects decrease with the vegetation cover gradient, their abundance in pitfall trapping increases. One possibility is that S. sthenodactylus are moving more on the active dunes compared to the semistable and stabilized dunes, but I suspect that the main reason for low track quantities recorded in the stabilized dunes is erosion by larger animal tracks. I did not record these data, but the amount of rodent tracks dramatically increases with dune stabilization, and I always suspected that we were underestimating activity levels of the reptiles that have delicate tracks, such as S. sthenodactylus, because they had been erased by rodents, foxes, hares and other animals crossing the transects. Detection of such delicate tracks is further hampered by organic matter, dead branches, vegetation debris and shade of shrubs, all of which occur at higher abundances with increased dune stabilization.

Another potential problem with track transects is accuracy in identification of the reptile tracks. All participants in the track transect data collection were experienced and knowledgeable regarding identification of reptile tracks, but successful identification depends also on conditions in the field (lighting at time of recording; degree of wind

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erosion of the transects; degree of inclination of the dune; level of activity of non- reptilian animals on transects; and so on). The most difficult tracks to identify, and most prone to identification errors, are snake tracks. When doubt arose, we recorded the tracks as "unidentified snake", in many cases making photographic records of the tracks to facilitate attempts at identification at a later time. The unidentified tracks were not included in the data analysis, since they are virtually useless for understanding species composition. Of a total of 16,247 reptile tracks recorded in the data set presented in this work, 192 were unidentified snake tracks, constituting a mere 1.18% of all reptile tracks recorded and 14.66% of all snake tracks (N=1,310) recorded. This is a relatively low figure, considering the variability in the expertise of the people who collected these data. Actively searching for snakes (at night or during the daytime) is very time consuming, and virtually impossible to conduct in an objectively systematic way across a large number of study plots (as is the case in the Nizzanim project). On the other hand, snakes are seldom captured in the type of pitfalls employed in this project, while occasional observations on snakes are very sporadic, yielding very low sample sizes. Thus, the only efficient method for sampling snake species composition and activity levels in large scale sand dune monitoring projects are track transects. I recommend adding daytime track transects to such projects, to boost sample sizes of data on diurnal snakes, but only if this is logistically feasible – for instance, if lacertid lizards are sampled by pitfall trapping during the day, so the reptile monitoring team is already working in the field during daytime.

The discussion has been focused up to this point on the more common species, since these are usually considered the most efficient biological or ecological indicators for monitoring. But it is important not to ignore or marginalize information regarding the rare species, especially in conservation oriented projects. Two rare desert specialist reptiles are known from Nizzanim sands, the desert monitor Varanus griseus and the false smooth snake Macroprotodon cucullatus. Since 1997, when I began documenting reptile observations in Nizzanim sands, I have observed M. cucullatus on only three occasions, and have found only indirect signs of V. griseus activity (tracks, burrows, faeces). In the data set presented here, both species were documented only by tracks (on transects or incidental). Nizzanim may be the northern most locality in Israel of viable populations for

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both species, which historically were probably present in the coastal sands as far north as the Tel Aviv area just south of the Yarqon river. I have recent evidence of V. griseus activity at Palmahim sands 20 km north of Nizzanim (Manor et al., 2007), and at Rishon LeZion sands 25 km north of Nizzanim (Shacham, unpublished data), but these may be remnant individuals fragmented from past metapopulations, thus they are doomed to become extinct at these locations. They are already extinct locally in the Holon area just north of Rishon LeZion, where they had been studied only three decades ago (Stanner, 1983; Stanner & Mendelssohn, 1987). I have not found any recent evidence of M. cucullatus presence north of Nizzanim. Another relatively rare species at Nizzanim is the lacertid lizard Mesalina olivieri, which is not considered rare in the Negev sandy habitats but Nizzanim is probably the northern (global) limit of this species. Sustaining long-term herpetofaunal diversity at Nizzanim must take into consideration the requirements of such rare species, not only requirements of the common reptiles. For V. griseus, the largest reptile in these sands (maximum total length circa 100 cm), large undisturbed and unfragmented sandy habitats are needed. The home range of an adult male is estimated at circa 1,000 m2, (Stanner, 1983; Stanner & Mendelssohn, 1987) thus the entire reserve (at approximately 21,000 m2) may support a maximum of 21 males but this is probably an overestimation, since the reserve does not include 100% suitable habitat for this species. For V. griseus to persist at Nizzanim, the reserve must be managed in such a way that the individuals may move freely about, with minimal disturbance of motorized vehicles which cause direct and indirect damage to the monitors, their burrows and their nests. For M. cucullatus, track transects data show that semistable and stabilized dunes are the preferred habitats for activity. For M. olivieri, observations in Nizzanim point to semistable dunes and especially their windward aspects as preferred habitat type. These habitats should be maintained for these species to be viable at Nizzanim. It would be very interesting, if resources were made available, to study the rare species more in depth and learn in detail their habitat requirements and population dynamics in Nizzanim.

None of the sampling methods I employed for this study would have achieved a full scope of the reptile fauna and its responses to the management treatments had I not combined their results. One of the greatest challenges I faced when analyzing the reptile data was how to successfully integrate these methods without over simplifying the data,

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yet still reaching coherent answers that represent reality. As I have discussed in this chapter, each sampling method may yield results which are biased towards different species, and sometimes different methods yield seemingly contradicting results. It is crucial for interpretation of the results to scrutinize and analyze each sampling method separately and to compare the findings to those of the integrated "poly-method" analysis. Since the questions we are asking in such studies are complex, there is no elegant solution for avoiding a complex methodology in order to find detailed answers. All of the methods we worked with demand basic knowledge and hands-on experience of the samplers, but personnel can be trained in advance by pairing novice observers with experienced ones for a period of "apprenticeship". The bottom line is, to properly monitor reptiles in sand dune projects, I recommend working with multiple sampling methods.

All the methodological issues I have discussed will contribute to improving the long- term monitoring of the reptile fauna in the Nizzanim sands project, and should be considered and implemented in future projects studying sand dune reptiles elsewhere. In Israel there are eco-geographic gradients in the coastal sandy habitats, with desert specialist species gradually decreasing and generalist species increasing from south to north, parallel to increased precipitation, decreased temperatures and decreased solar irradiation (Perelberg et al., 2005). Thus, implementation of the conclusions and recommendations from my study must be fine-tuned according to the location as compared to Nizzanim sands on the south-north axis. For instance, monitoring of sand dune reptiles conducted north of the Yarqon river, which is considered the northern limit of Acanthodactylus scutellatus, must take into account that A. schreiberi has an expanded niche breadth in the absence of its competing congener (Shacham, unpublished data). When working in Israel's coastal dunes, one must bear in mind that the sands become narrower on the west-east axis from south to north, on average, thus the influence of generalist species living in adjacent habitats to the east and the potential impacts of anthropogenic factors increase as one goes north. When working in the Negev dunes, it is important to note that the effects of biogenic crusts may outweigh those of vegetation encroachment on reptile fauna (both processes are contribute to sand stabilization), with dire consequences for burrowing sand specialist reptiles. Much of what I did at Nizzanim

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is applicable elsewhere, but any future projects at other sites should be tailored for their specific localities.

With the ultimate goal of the project – sustainable conservation of Israel's coastal sands ecosystem – in mind, I plan to integrate in the future my results from this study of the reptiles with the data from other teams working on their respective taxa, thus enabling us to get a better perspective for using the studied management techniques.

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Potential Obstacles: How does the Project Measure Up?

There are a great many potential obstacles, which may slow down or cause failure of ecological restoration projects; here I consider how some of the main obstacles mentioned in the literature are dealt with in this project (adapted from Lake, 2001):

1. Participation of resource management agencies in significant projects – Rather than carry out many small-scale projects, it is advisable to undertake a limited number of well-designed large-scale projects. The Nizzanim project has been planned and is being executed by a relatively large group of partners from both academia and nature conservation authorities.

2. Adequate design of restoration projects – Restoration projects must be designed in such a manner that robust data may be collected, analyzed and applicable conclusions be drawn within a reasonable time frame. This includes several main components:

• Before-data – An entire season of data collection was conducted before any intervention (manipulation) was carried out in Nizzanim sands, making sure adequate "before" data was collected at the manipulated sites (with the exception of the three dunes manipulated by INPA).

• Replication – Each plot type at Nizzanim has at least three (3) replicates.

• Control and/or reference sites – Each manipulated plot category has both control (similar "before" qualities, not manipulated) and reference (naturally occurring "target" qualities) plots, thus we may compare the manipulated plots simultaneously to the "untouched" state and the targeted "end product".

• Feasible goals – Considering the timetables, workloads and manpower at the start of the project, our initial goals are indeed feasible in the short and mid- term timescales (up to 5-7 years).

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• Capacity to test hypotheses – Experimental design should allow testing of the proposed research hypotheses within the project framework.

3. Monitoring of restoration projects – To allow empiric evaluation of restoration actions, it is important to monitor and document:

• State of the inputs – record relevant data before undertaking restoration activity;

• Restoration manipulation – record in detail all manipulative actions undertaken;

• Ecological responses – such that are relevant to gauge effects of restoration;

• Choosing appropriate indicators – such that will provide answers to questions regarding the effectiveness of the restorative actions, while optimizing resources (time, manpower, equipment) needed for monitoring these indicators.

All these points have been followed in the Nizzanim Project.

4. Reporting of restoration projects – Especially important is reporting of failures, since future restoration projects depend on published reports to avoid repeating mistakes made in past projects. Apart from this dissertation, the results of this work shall be published in the scientific literature (peer-reviewed journals). Since the start of the Nizzanim project, the various teams working on their respective taxa have published results, at progressive stages, of the research at local and international scientific conferences.

5. Consideration and resolution of scale in restoration projects:

• “Hysteresis of repair” – repair of the system may have a much longer trajectory than that of the degradation process;

• Spatial-temporal scale correlation may govern rate of restoration;

• The short-term nature of funds, managers and politicians;

• Different biota differ in response rates to restoration.

All these points are taken into account in the Nizzanim Project.

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Summary of Conclusions from Nizzanim Sands

1. Reptile assemblages are greatly affected by perennial vegetation levels – reptile species composition is dictated by total perennial vegetation cover, with strong correlations to proportion of vegetation life forms (bush, semi-bush and perennial grass) with autocorrelations to plant species.

2. Total reptile species richness and abundance are positively correlated with total perennial vegetation cover – but this is due to an increase in generalist species presence as vegetation cover increases, while desert specialist species presence remains relatively constant.

3. Partial vegetation removal caused detectable changes in reptile species assemblages – but none of the three treatment regimes tested has reached targeted assemblages and only one out of the three shows a trajectory that may reach the target.

4. Partial vegetation removal caused detectable physical responses in some reptile species – in two common lizards, S. sepsoides and S. sthenodactylus, elevated tail loss frequencies in treated dunes and slight improvement in body condition indices seem to mirror trends seen in natural active dunes.

5. It is too early to pass judgment on success or failure of the management – as it is only four years post-treatment, there may be a long lag ("hysteresis of repair") of response of the reptile fauna; and for two of the three treatment regimes, exists a problem of physical disconnect of the study plots from source populations (metapopulations), which may be remedied by relocating individuals and creating suitable corridors.

6. Multiple sampling methods are required, and a system to integrate them is described – abandoning any of the three main sampling methods used (track transects, pitfall trapping, diurnal lizard activity transects) would have meant loss of crucial information for interpretation of the reptile assemblages, and potentially misled conclusions. Each method has its pros and cons, but combined they give

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the broadest possible picture, which is important for conservation oriented management strategy.

7. New questions for study and suggestions for improving sampling effort at Nizzanim are offered – among them, increasing sampling effort of S. sepsoides and S. sthenodactylus; pitfall trapping of the diurnal Acanthodactylus species; specifically studying activity patterns of the rare species such as M. cucullatus.

Summary of Recommendations for Monitoring Sand Dune Reptiles

1. Use multiple sampling methods – for optimal coverage of maximal number of species.

2. Analyze methods separately before integrating them – to explore effects that may not stand out later, and check for conformity or contradiction between methods.

3. Integrate results from various methods carefully – to avoid over-simplification and loss of information.

4. Do not marginalize rare species – they are valuable from a conservation perspective and may easily fall between the cracks.

5. Sample different seasons each year – but focus on spring and autumn, or spring only, if sampling efforts are limited.

6. Make every effort to obtain baseline data before management actions – preferably from in situ sampling, but if impossible then from previous databases.

7. Explore behavioral and physical responses to management actions – they may be present even if assemblage responses are absent or weak, and are potentially important for conservation planning.

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New Study Questions Arising from this Project

As in any large scale scientific project, many new questions regarding the reptiles in Nizzanim were born while I was attempting to answer my original study questions. A small selection of such potential study questions is presented here.

1. Are there changes in behavior of the Acanthodactylus lizards in response to vegetation manipulation? – Preliminary data has been collected for assessing differences in habitat use, foraging behavior and time allocation of these lizards in different dune types. These data were collected by undergraduate project students, using a PDA based data collection system (Held & Manser, 2005), in Nizzanim sands. Currently, graduate student Sharon Paz-Renan is collecting similar data for comparison of A. schreiberi behavior at different geographic sites along the coastal dunes, as part of her M.Sc study. The next step would obviously be to assess, using the same methodology, whether Acanthodactylus lizards change their behavior in response to the changes affected to their habitat by the manipulation treatments.

2. Are the trends seen in tail loss frequency and body condition index of some lizard species in post treatment dunes significant, and what are the mechanisms for these responses? – The increased tail injury frequency and elevated body condition indices observed in S. sepsoides and S. sthenodactylus may or may not be significant, extra sampling effort would lead larger sample sizes to elucidate this matter. If these are truly significant effects, it would be interesting to test the hypothesized mechanisms for the increase in tail injuries (increased predation pressures?), the elevated body condition (decreased competition for resources?) and the differences in tail injury frequency between the two species (different evolutionary strategies regarding tail autotomy?).

3. How high are morphological and genetic variations within and between populations of sand dwelling reptiles along the eco-geographic gradient in Israel, and are these variations correlated with each other? – Some of the sand dwelling

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reptiles in Israel are present along a wide eco-geographic gradient, from the 'Arava valley (Rift valley) in the south, through the Negev sand dunes and northward along the coast into the Mediterranean climatic zone. For example, S. sthenodactylus is the most widely distributed and occurs along the entire gradient, up north into the coastal dunes and Kurkar formations of southern Lebanon's Mediterranean coast. S. sepsoides is found at least as far north as 'Atlit (Tantara beach), just south of the Carmel mountains, while northern limit of the snake Lytorhynchus diadema is the by the Yarqon river. In each of these species, as well as in others, anecdotal observations have been made on morphological variation (color, pattern, size and so on) between different geographic populations, but to date no empirical studies have been conducted regarding this variation. I suggest that the morphological variation within and between geographically separate populations of these species be compared, as well as genetic variation, on the same individuals sampled for morphology. Such a study would yield taxonomic information on possible speciation in these species, and supply important data for making conservation and management decisions regarding sand dune habitats.

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References

Adler, R. 1985. Atlas of Israel: cartography, physical and human geography, 3rd ed. Survey of Israel, Tel Aviv.

Ahirun-Frumkin T., Frumkin R., Rudikh R., Malul A., Levin N. & Papai N. 2003. Conservation of the coastal sands of Israel – Policy paper. State of Israel Ministry of the Environment, the Society for the Protection of Nature in Israel, Israel Nature & Parks Authority, Jewish National Fund, Hydrological Service of Israel (Israel Water Authority) and the Jerusalem Institute for Israel Studies. Survey unit, DESHE Institute, Tel Aviv (126 pages, in Hebrew).

Amir D. & Shapira A. 2005. Environmental-Landscape Appendix to Partial National Layout Plan of Nizzanim – Northern Ashqelon Area. State of Israel Ministry of the Interior: http://www.moin.gov.il/Apps/PubWebSite/publications.nsf (Hebrew).

Andrews R.M. & Wright S.J. 1994. Chapter 12: Long-term population fluctuations of a tropical lizard: A test of causality. Pp 267-285. In: Lizard Ecology: Historical and Experimental Perspectives. Eds.: Vitt L.J. & Pianka E.R. Princeton University Press, Princeton, New Jersey (403 pp.).

Anglister N., Motro U. & Yom-Tov Y. 2005. The effect of Acacia saligna and dune stabilization on rodent populations in Ashdod-Nizzanim sands. Abstract, in: Proceedings of the 41st Annual Meeting of the Zoological Society of Israel, Haifa, 12 December 2004. Israel Journal of Zoology, 51: 58

Arens S.M., Slings Q. & de Vries C.N. 2004. Mobility of a remobilised parabolic dune in Kennemerland, The Netherlands. Geomorphology, 59: 175-188.

Arthur A.D., Pech R.P. & Dickman C.R. 2004. Habitat structure mediates the non-lethal effects of predation on enclosed populations of house mice. Journal of Animal Ecology, 73: 867-877

Avital E. 1981. Resource partitioning between two lizard species of the genus Acanthodactylus, living in the same area of sand dunes. Dissertation for M.Sc. in Zoology, The Hebrew University of Jerusalem.

117 Boaz Shacham – PhD dissertation

Ayal Y. 2000. The role of habitat productivity and plant structure in the determination of herbivore size and the number of trophic levels in terrestrial communities. Communicating and Advancing Ecology, p. 47.

Ayal Y. & Merkl O. 1994. Spatial and temporal distribution of tenebrionid species (Coleoptera) in the Negev highlands, Israel. Journal of Arid Environments, 27: 347- 361.

Baker H.G. 1986. Patterns of plant invasion in North America. In: H.A. Mooney and J.A. Darke (eds.). Ecology of Biological Invasions of North America and Hawaii. Springer-Verlag, New York, NY. Pp. 44-56.

Barrows C.W. & Allen M.F. 2009. Patterns of occurrence of reptiles across a sand dune landscape. Journal of Arid Environments, 74: 186-192.

Bergin D.O. & Kimberly M.O. 1999. Rehabilitation of coastal foredunes in New Zealand using indigenous sand-binding species. Department of Conservation Science for Conservation Series No. 122, 55 pp.

Berglind S-A. 2004. 29. Sand lizard (Lacerta agilis) in central Sweden: Modeling juvenile reintroduction and spatial management strategies for metapopulation establishment. In: Akçakaya H.R., Burgman M.A., Kindvall O., Wood C.C., Sjorgen-Gulve P., Hatfield J.S. & McCarthy A. (Eds.). 2004. Species conservation and management: Case studies. Oxford University Press, Oxford, 533 pp.

Boeken B. & Shachak M. 1998. The dynamics of abundance and incidence of annual plant species during colonization in a desert. Ecography, 21, 63-73

Bouskila A. 2002. Reptiles. In: A. Dolev & A. Perevolotsky (eds.). Red Data Book of Vertebrates in Israel, Yefeh Nof, Jerusalem, Israel. (English and Hebrew editions).

Bouskila A. & Amitai P. 2001. A Handbook of the Reptiles and Amphibians of Israel, Keter Publishing House (in Hebrew, 345 pp.).

Bouskila A. & Dickman C.R. (unpublished MS). Species diversity of vertebrate communities in arid lands. In: M. Shachak, S. T. A. Pickett, J. R. Gosz and A. Perevolotsky (eds.). Biodiversity in Drylands: Towards a Unified Framework for Research and Management. Oxford University Press, Oxford.

118 Boaz Shacham – PhD dissertation

Brisson J.A., Strasburg J.L. & Templeton A.R. 2003. Impact of fire management on the ecology of collared lizard (Crotaphytus collaris) populations living on the Ozark Plateau. Animal Conservation 6: 247-254.

Chapman M.G. & Underwood A.J. 2000. The need for a practical scientific protocol to measure successful restoration. Wetlands (Australia), 19: 28-49.

Coakes S.J. & Steed L.G. 2001. SPSS: analysis without anguish, Version 10.0 for windows edn. John Wiley & Sons, Brisbane.

Cohen O., Kutiel P., Shoshany M. & Shuv M. 2003. The invasion rate of the alien species Acacia saligna within Nitzanim coastal sand dune, Israel. Horizons in Geography, 55: 79-96 (In Hebrew, with English abstract).

Collins T. 2004. The Tzin River Valley – A proposal to restore the land and cultural values taken by a phosphate mine. Text derived from a workshop at the 1st Israel Biennale of Eco-Art.

Collins S.L., Glenn S.M. & Gibson D.J. 1995. Experimental analysis of intermediate disturbance and initial floristic composition: Decoupling cause and effect. Ecology, 76: 486-492.

Connell J.H. 1978. Diversity in tropical rain forests and coral reefs. Science, 199: 1302- 1310.

Crawford C.S. 1981. Biology of Desert Invertebrates. Berlin, Springer-Verlag.

D'Antonio C.M. 1993. Mechanisms controlling invasion of coastal plant communities by the alien succulent Carpobratous edulis. Ecology, 74: 83-95.

Doing H. 1997. Landscape ecology of the Dutch coast. In: G.N. Crawford and C.D. Barradas (eds.). The Ecology and Conservation of European dunes. Universidad de Sevilla.

Dolev A., Shacham B. & Berger H. 2002. Report of zoological survey of the southern coastal sands of Israel – reptiles and mammals, in the nature reserves: Palmahim, Mevo Ashdod and Nizzanim. The Society for the Protection of Nature in Israel, submitted to the INPA (Israel Nature & Parks Authority) (in Hebrew).

119 Boaz Shacham – PhD dissertation

Doody J.P. 2000. Coastal conservation and management: An ecological perspective. Kluwer Academic Publishers; The Netherlands. 328 pages.

Fischer J., Lindenmayer D.B. & Cowling A. 2004. The challenge of managing multiple species at multiple scales: reptiles in an Australian grazing landscape. Journal of Applied Ecology, 41: 32-44.

Grime J.P. 1973.Competitive exclusion in herbaceous vegetation. Nature, 242: 344-247.

Groner E. & Ayal Y. 2001. The interaction between bird predation and plant cover in determining habitat occupancy of darkling beetles. Oikos, 93: 22-31.

Hauser M. & Irwin M.E. 2003. The North American genus Ammonaios (Diptera: Therevidae). Annals of the Entomological Society of America, 96: 738-765.

Hawlena D. & Bouskila A. 2006. Land management practices for combating desertification cause species replacement of desert lizards. Journal of Applied Ecology, 43: 701-709.

Held J. & Manser T. 2005. A PDA-based system for online recording and analysis of concurrent events in complex behavioural processes. Behavior Research Methods, 37: 155-164.

Hester M.W., Wilsey B.J. & Mendelssohn I.A. 1994. Grazing of Panicum amarum in a Louisiana Barrier Island dune plant community - management implications for dune restoration project. Ocean & Coastal Management, 23: 213-224.

Higgs E. 2003. "Nature by Design", MIT Press, Cambridge MA

Hobbs R.J. & Huenneke L.F. 1992. Disturbance, diversity, and invasion: Implications for conservation. Conservation Biology, 6: 324-337.

Holmes P.M. & Cowling R.M. 1997. The effect of invasion by Acacia saligna on the guild structure and regeneration capabilities of South African fynbus shrublands. Journal of Applied Ecology, 34: 317-332.

Horn H.S. 1975. Markovian properties of forest succession, pp. 196-211 in: Cody, M.L. & Diamond, J.M. (Eds), Ecology and evolution of communities, Belknap Press, Cambridge, MA.

120 Boaz Shacham – PhD dissertation

Ioannidis Y. & Bousbouras D. 1997. The space utilization by the reptiles in Prespa National Park. Hydrobiologia, 351: 135-142

Irwin M.E. 2001. Species composition and seasonal flight periodicity of stiletto flies (Diptera: Therevidae) occurring along the Kuiseb River, Gobabeb, Namibia. Cimbebasia, 17: 169-175.

Jones C.G., Lawton J.H. & Shachak M. 1994. Organisms as ecosystem engineers. Oikos, 69: 373-386.

Kirkman T.W. 1996. Statistics to Use. http://www.physics.csbsju.edu/stats/ (17 July 2009).

Kooijman A.M. & van der Meulen F. 1996. Grazing as a control against grass- encroachment in dry dune grasslands in the Netherlands. Landscape and Urban Planning, 34: 323-333.

Kutiel P., Danin A. & Orshan G. 1979/80. Vegetation of the sandy soils near Ceasarea, Israel. I. Plant communities, environment and succession. Israel Journal of Botany, 28: 20-35.

Kutiel P. & Sharon H. 1996. Landscape changes in the last 50 years in the area of HaSharon Park, Israel. Ecology and Environment, 3: 167-176 (In Hebrew, with an English abstract).

Kutiel P., Shahar Z., Paryente R. & Jaimes E. 1997. Management in a sandy nature reserve – an experiment for conservation of Gerbillus andersoni allenbyi. Ecology and Environment, 4: 35-40 (In Hebrew, with an English abstract).

Kutiel P. 19981. Possible role of biogenic crusts in plant succession on the Sharon sand dunes, Israel. Israel Journal of Plant Sciences, 46: 279-286.

Kutiel P. 19982. Annual vegetation of the coastal sand dunes, Israel. Israel Journal of Plant Sciences, 46: 287-298.

Kutiel P., Zhevelev H. & Harrison R. 1999. The effect of recreational impacts on soil and vegetation of stabilized coastal dunes in the Sharon Park, Israel. Ocean & Coastal Management, 42: 1041-1060.

121 Boaz Shacham – PhD dissertation

Kutiel P., Peled Y. & Geffen E. 2000. The effect of removing shrub cover on annual plants and small mammals in a coastal sand dune ecosystem. Biological Conservation, 94: 235-242.

Kutiel P., Zhevelev Y. & Eden Z. 2000. Vegetation and soil response to experimental off-road motorcycle and pedestrian traffic in Mediterranean stabilized coastal dunes. Environmental Conservation, 27: 14-23.

Kutiel P. 2001. Conservation and management of the Mediterranean coastal sand dunes in Israel. . Journal of Coastal Conservation, 7: 183-192.

Kutiel P., Cohen O., Shoshany M. & Shub M. 2002. Vegetation establishment on the southern Israeli coastal sand dunes between the years 1965-1999. Landscape and Urban Planning, (special issue).

Kutiel P., Cohen O., Shoshany M. & Shub M. 2004. Vegetation establishment on the southern Israeli coastal sand dunes between the years 1965 and 1999. Landscape and Urban Planning, 67: 141-156.

Lake P.S. 2001. On the maturing of restoration: linking ecological research and restoration. Ecological Management & Restoration, 2: 110-115.

Lepš J. & Šmilauer P. 2003. Multivariate analysis of ecological data using CANOCO. Cambridge University Press, Cambridge. 282 pp.

Levin N. & Ben-Dor E. 2004. Monitoring sand dune stabilization along the coastal dunes of Ashdod-Nizanim, Israel, 1945-1999. Journal of Arid Environments, 58: 335-355.

Levin N., Ben-Dor E. & Karnieli A. 2004. Topographic Information of Sand Dunes as Extracted from Shading Effects Using Landsat Images. Remote Sensing of Environment, 90: 190-209.

Levin N., Ben-Dor A. & Kidron G. 2003. Influence of anthropogenic factors on temporal changes in stabilization rates of sand dunes in Ashdod-Nizzanim sands. Horizons in Geography, 57-58: 224-241 (in Hebrew).

122 Boaz Shacham – PhD dissertation

Litt A.R., Provencher L., Tanner G.W. & Franz R. 2001. Herpetofaunal responses to restoration treatments of longleaf pine sandhills in Florida. Restoration Ecology, 9: 462-474.

Lopatin I. K. & Chikatunov V. I. 1999. Two new species of Cryptocephalus from Israel (Coleoptera: Chrysomelidae). Zoosystematica Rossica, 8: 329-330.

Manor R., Shacham B. & Dolev A. 2007. Report on zoological survey for assessing effects of invasive vegetation on small mammals and reptiles in Palmahim sands reserve. Internal report submitted to SPNI (the Society for the Protection of Nature in Israel) (in Hebrew).

McCoy E.D., Sutton P.E. & Mushinsky H.R. 1999. The role of guesswork in conserving the threatened sand skink. Conservation Biology, 13: 190-194.

McManus D. 1988. Plant community dynamics on sand dunes at Murlough National Nature Reserve, Dundrum, Co. Down, Northern Ireland. M. Phil. Thesis, University of Ulster at Jordanstown, Department of Environmental Studies: 377 pp.

Mittelbach G.G., Steiner C.F., Scheiner S.M., Gross K.L., Reynolds H.L., Waide R.B., Willig M.R., Dodson S.I. & Gough L. 2001. What is the observed relationship between species richness and productivity? Ecology, 82: 2381-2396.

Molles M.C. Jr. 2009. Ecology: Concepts and Applications. 5th Edition, McGraw-Hill, Boston. 608 pp.

Moulton N. & Corbett K. 1999. The sand lizard conservation handbook. English Nature, Peterborough, UK.

Naveh Z. & Kutiel P. 1990. Changes in vegetation of Mediterranean Basin in response to human habitation. In: G. Woodwell (ed.). The Earth in Transition: Patterns and Processes of Biotic Impoverishment. Cambridge Press, pp. 259-300.

Nichols J.D., Bailey L.L., O’Connell Jr. A.F., Talancy N.W., Campbell Grant E.H., Gilbert A.T., Annand E.M., Husband T.P. & Hines J.E. 2008. Multi-scale occupancy estimation and modelling using multiple detection methods. Journal of Applied Ecology, 45: 1321-1329.

123 Boaz Shacham – PhD dissertation

Nordstrom K.F. & Lotstein E.L. 1989. Perspectives on resource use of dynamic coastal dunes. Geographical Review, 79: 1-12.

Palmer M.A., Ambrose R.F. & Poff N.L. 1997. Ecological theory and community restoration ecology. Restoration Ecology, 5: 291-300.

Perelberg A., Dolev A., Shacham B., Guter A. & Talbi R. 2005. Mammals and reptiles survey at the central coastal plain of Israel as a means for quantifying the importance of sandy habitats for conservation. Poster presentation: ISEEQS 2005 (Israel Society for Ecology and Environmental Quality Sciences) (in Hebrew).

Perry M.P. 2008. Studying perennial plant impact on annual diversity in sand dunes in different spatial scales. Dissertation for M.Sc. at the Jacob Blaustein Institute for Desert Research, Ben-Gurion University of the Negev.

Ramot A. 2007. Effects of plant cover on arthropod communities in the Nizanim coastal dunes. Dissertation for M.A. at the Dept. of Geography and Environmental Development, Ben-Gurion University of the Negev.

Rosenzweig M.L 1995. Species Diversity in Space and Time, Cambridge Univ. Press, Cambridge, UK. 414 pp.

Rosenzweig M.L. 2001. The four questions: What does the introduction of exotic species do to diversity? Evolotionary Ecology Research, 3: 361-367.

Rudikh R. & Farjun Y. 1999. Sand Dune Park – Survey for future planning. The Society for the Protection of Nature in Israel, submitted to the JNF (Jewish National Fund) (in Hebrew).

Schoener T.W. & Schoener A. 1980. Ecological and demographic correlates of injury rates in some Bahamian Anolis lizards. Copeia, 1980: 839–840

Scott T.A., Wehtje W. & Wehtje M. 2001. The need for strategic planning in passive restoration of wildlife populations. Restoration Ecology, 9: 262-271.

Seligmann H., Beiles, A. & Werner Y.L. 1996. Tail loss frequencies of lizards and predator specialization. Proceedings of the sixth International Conference of the Israeli Society for Ecology & Environmental Quality Sciences 6: 520-522.

124 Boaz Shacham – PhD dissertation

Seligmann H., Beiles A. & Werner Y.L. 2003. Avoiding injury and surviving injury: two coexisting evolutionary strategies in lizards. Biological Journal of the Linnean Society 78: 307-324.

Shacham B. 2004. Polymorphism in the schokari sand snake (Psammophis schokari) in the coastal sand dunes of Israel. Dissertation for M.Sc. in Evolution, Systematics & Ecology, The Hebrew University of Jerusalem.

Shacham B. & Bouskila A. 2007. Vegetation removal as a management tool in Nizzanim dunes (Israel): Preliminary assessment of effects on reptile and mammal populations. Proceedings, International Conference on Management and Restoration of Coastal Dunes (ICCD 2007), Santander, Spain 3-5 October 2007, pp 144-145.

Shalmon B. 2002. Mammals. In: A. Dolev and A. Perevolotsky (eds.). Red Data Book of Vertebrates in Israel. Yefeh Nof, Jerusalem, Israel. (English and Hebrew editions).

Sher A.A. & Hyatt L.A. 1999. The disturbed resource - flux invasion matrix: A new framework for patterns of plant invasion. Biological Invasion, 1: 107-114.

Shmida A. 1982. The endemic plants of Israel. Rotem, 3: 3-47 (in Hebrew with an English abstract).

Slobodchikoff C.N. & Doyen J.T. 1977. Effects of Ammophila arenaria on sand dune arthropod communities. Ecology, 58: 1171-1175.

Society for Ecological Restoration International Science & Policy Working Group 2004. The SER International Primer on Ecological Restoration. www.ser.org & Tucson: Society for Ecological Restoration International.

Stanner M. 1983. The Etho-Ecology of the desert monitor (Varanus griseus) in the sand Dunes South of Holon, Israel. Dissertation for M.Sc. in Zoology, Tel-Aviv University.

Stanner M. & Mendelssohn, H. 1987. Sex ratio, population density and home range of the desert monitor (Varanus griseus) in the southern coastal plain of Israel. Amphibia-Reptilia, 8: 153-164.

125 Boaz Shacham – PhD dissertation

ter Braak, C. J. F. & Šmilauer, P. 2002. CANOCO Reference Manual and CanoDraw for Windows User's Guide: Software for Canonical Community Ordination (version 4.5). Microcomputer Power (Ithaca NY, USA), 500 pp.

Thompson G.G., Withers P.C., Pianka E.R. & Thompson S.A. 2004. Assessing biodiversity with species accumulation curves; inventories of small reptiles by pit- trapping in Western Australia. Austral Ecology 28: 361-383.

Townsend C.R., Scarsbrook M.R. & Dolédec S. 1997. The intermediate disturbance hypothesis, refugia, and biodiversity in streams. Limnology & Oceanography, 42: 938-949.

Tsoar H. & Blumberg D.G. 2002. Formation of parabolic dunes from barchan transverse dunes along Israel’s Mediterranean coast. Earth Surface Processes and Landforms 27: 1147-1161.

van der Meulen F. & Salman A.H.P.N. 1996. Management of coastal dunes. Ocean & Coastal Management, 30: 177-195.

Wasserberg G. 1997. Centrifugal organization in a community of desert gerbils: revealing the mechanism that underlies the pattern. M.Sc Thesis, Dept. of Life Sciences, Ben Gurion University.

Wasserberg G., Abramsky Z., Valdivia N. & Kotler B.P. 2005. The role of vegetation characteristics and foraging substrate in organizing a centrifugal gerbil community. Journal of Mammalogy, 86: 1009-1014.

Werner Y.L. 1987. Ecological zoogeography of the Saharo-Arabian, Saharan and Arabian reptiles in the sand deserts of southern Israel, pp. 272-295, in: Krupp, F., Schneider, W. & Kinzelbach, R. (Eds.), Proceedings of the Symposium on the Fauna and Zoogeography of the Middle East, Mainz 1985, TAVO Beiheft 28A, Wiesbaden.

Werner Y.L. 1988. Herpetofaunal survey of Israel (1950-85), with comments on Sinai and Jordan and on zoogeographical heterogeneity, pp. 355-388, in: Yom-Tov, Y. & Tchernov, E. (Eds.), Zoogeography of Israel, Monographiae Biologicae, Junk, The Hague.

126 Boaz Shacham – PhD dissertation

White P.S. & Pickett S.T.A. 1985. Natural disturbance and patch dynamics: an introduction, pp. 3-13, in: Pickett, S.T.A. & White, P.S. (Eds.), The ecology of natural disturbance and patch dynamics, Academic Press, New York. 472 pp.

Wright S.J. 2007. Alaska coastal dune restoration and stabilization with beach ildrye, Leymus mollis – A career’s worth of activity. Proceedings, International Conference on Management and Restoration of Coastal Dunes (ICCD 2007), Santander, Spain 3- 5 October 2007.

Yom-Tov Y. & Mendelssohn H. 1988. Changes in the distribution and abundance of vertebrates in Israel during the 20th century. In: Y. Yom-Tov and E. Tchernov (eds.). The Zoogeography of Israel. Dr W. Junks Publishers, Boston, pp. 515-547.

Zaady E. & Bouskila A. 2002. Lizard burrows association with successional stages of biological soil crusts in an arid sandy region, Journal of Arid Environments, 50: 235- 246.

Zahavi A. & Wahrman J. 1957. The cytotaxonomy, ecology and evolution of the gerbils and jirds of Israel (Rodentia: Gerbillinae). Mammalia, 21: 342-380.

Zar J.H.H. 1998. Biostatistical Analysis, 4th edn. Prentice-Hall, Inc., Upper Saddle River.

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Appendix I: Restoration Ecology – Definitions, Strategies, Potential Problems, Design

Definition of Basic Terms

Restoration, rehabilitation and reclamation are the terms used within the Society for Ecological Restoration (SER) that are most applicable to our site (Society for Ecological Restoration International Science & Policy Working Group, 2004). I follow the standards of this international organization as I define the relevant terms:

• Ecological restoration is the process of assisting the recovery of an ecosystem that has been degraded, damaged, or destroyed. It relies upon intact soils and hydrology as well as an intact reference ecosystem to construct a plausible replacement with the potential for authentic form and function.

• Rehabilitation shares with restoration a fundamental focus on historical or pre-existing ecosystems as models or references, but the two activities differ in their goals and strategies. Where restoration adheres to strict goals, "rehabilitation establishes an acceptable ecological state, where prudential and aesthetic conditions prevail." (Higgs, 2003).

• The term reclamation, is commonly used in the context of mined lands in North America and the UK, has an even broader application than rehabilitation. The main objectives of reclamation include the stabilization of the terrain, assurance of public safety, aesthetic improvement, and usually a return of the land to what, within the regional context, is considered to be a useful purpose (not necessarily the original or a specific ecological state).

The best-case scenario of the management experiment in Nizzanim dunes is to ecologically restore the ecosystem. If, ultimately, the methodology used will fail to produce a restored ecosystem, there will at least be rehabilitation of the sand dune ecosystem to a certain extent.

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Conceptual Framework

Several theoretical and operational questions must first be addressed, in any restoration project, as part of the project's basic conceptual framework (following Collins, 2004):

• First, why would we rehabilitate such a habitat? In our case, the reason to rehabilitate the coastal sand dunes is the fact that they constitute a unique ecosystem, in which a temperate climate meets semi-arid conditions (the sand itself). A mere fraction of this ecosystem survives today, due to enormous developmental pressures and land use changes spanning the last six decades. This is an important place that deserves our attention. The logical reason that follows is that a true rehabilitation is very hard work. It forces us to reconsider short-term thinking, and to consider sustainable land uses. The effort required to rehabilitate this place brings perspective to the tools that we have developed to take nature apart and extracts its hidden resource.

• Second, how would we rehabilitate such a habitat? The means to rehabilitate must be found within existing institutions and techniques. It will take time and long-term attention to rehabilitate even the smallest parcel of the coastal sands. There may be a process of trial-and-error regarding the adequate technique, for instance (remove vegetation manually, by machine or by grazing?). To do this well it will be important that all parties involved cooperate well: academic researchers, Israel Nature and Parks Authority, the Jewish National Fund, environmentalists, students, and members of various community councils.

• Third, what would we rehabilitate? We would rehabilitate as much as possible, but assure that what we choose to act upon achieves success. In practical terms, decisions regarding the projected targets of the rehabilitated habitats must be made (rehabilitate stabilized dunes to active sand state? To semistable sand state? Experiment with both?). If it is decided to pursue this idea it is essential that the program be successful, that it be public and that it be widely owned by the sum of its participants rather than any single

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individual, scientist or institution. The recovery should be monitored and interpreted.

Preliminary Assessment

When approaching a restoration project, several preliminary assessments must be made as initial steps (adapted from Lake, 2001):

1. Assessment of condition and “restorability”:

• Identify the degrading forces;

• Assess their current status and strength;

• Rank them in a priority order of severity;

• Determine likelihood of degradation abatement and consequent recovery following restoration.

2. Assessment of linkages:

• Form and strength of linkages between the locality and its surrounds;

• Connections between restored locality and sources (colonists)/resources;

• Are there critical buffer/transition zones?

• Are there impeding influences in the surrounds?

• Whereabouts and state of undamaged areas – as “sources” and references.

Both of these assessments were indeed made before any management actions were taken at Nizzanim; unfortunately, due to logistical considerations, not all the experimentally restored localities were adequately connected to colonizing sources for reptile assemblages.

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Thematic Questions

When trying to link community ecological theory with restoration ecology, and build restoration on the theoretical foundations, we must focus on several thematic questions that arise (Palmer et al., 1997):

1. What are appropriate restoration endpoints from a community ecology perspective?

2. What are the benefits and limitations of using species composition (or biodiversity measures) as endpoints in restoration ecology?

3. Is restoration of habitat a sufficient approach to reestablish species and function?

4. To what extent can empirical and theoretical work on community succession and dispersal contribute to restoration ecology?

Potential Difficulties Interpreting Outcomes of Restoration

As in any complex system, an ecosystem undergoing restoration may present a trajectory that is difficult for interpretation, such as:

1. Hypothesized response may have a lag response;

2. System may proceed to an unforeseen (and stable) state;

3. System may not have any clear trajectory and stability.

The Need for Strategic Planning in Restoration

When attempting passive restoration of wildlife populations, strategic planning is needed to achieve success, and this is for two reasons (Scott et al., 2001):

1. To maximize the potential for colonization of restoration sites in challenged landscapes.

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2. To maximize the contribution of each restoration project to regional, management area, ecosystem, or target species goals.

Equal weight must be given to both context (likelihood of site colonization by target species) and content (habitat) of restoration projects. Due to various logistical and other constraints, not all of the specific sites chosen for experimental restoration in the Nizzanim project had maximal potential for colonization by all target reptile species. This is one of the disadvantages of working within a large study covering multiple taxa.

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Appendix II: Herpetofaunal Checklist of Nizzanim Sands and Environs. Table 23: Reptile species checklist of Nizzanim sands and environs. Family Species (Family) Category Activity Habitat(s) Testudinidae Testudo graeca generalist D A,B,D,K,O Gekkonidae Hemidactylus turcicus generalist N K,O Gekkonidae Ptyodactylus guttatus generalist D/N K,O Gekkonidae Cyrtopodion kotschyi generalist D/N B,D,K,O Gekkonidae Stenodactylus sthenodactylus desert N A,B,D,K Agamidae Laudakia stellio stellio generalist D D,K,O Chamaeleonidae Chamaeleo chamaeleon generalist D A,B,D,K,O Lacertidae Acanthodactylus schreiberi generalist D A,B,D,K Lacertidae Acanthodactylus scutellatus desert D A,B Lacertidae Mesalina olivieri desert D A,B Scincidae Sphenops sepsoides desert N A,B,D,K Scincidae Chalcides ocellatus generalist F A,B,D,K,O Scincidae Chalcides guentheri generalist D K Scincidae Eumeces schneideri pavimentatus generalist D K Scincidae Mabuya vittata generalist D B,D,K, O Scincidae Ablepharus rueppellii generalist D B,D,K,O Anguidae Ophisaurus apodus generalist D B,D,K,O Varanidae Varanus griseus desert D A,B Typhlopidae Typhlops vermicularis generalist F A,B,D,K,O Boidae Eryx jaculus generalist N B,D,K Colubridae Eirenis rothi generalist D K Colubridae Eirenis decemlineata generalist D K Colubridae Rynchocalamus melanocephalus generalist D/N K Colubridae Coluber jugularis generalist D B,D,K,O Colubridae Coluber rubriceps generalist D B,D,K,O Colubridae Coluber nummifer generalist D/N K,O Colubridae Natrix tessellata generalist D D,K,O Colubridae Lytorhynchus diadema desert N A,B,D

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Colubridae Spalerosophis diadema desert D/N A,B,D,O Colubridae Macroprotodon cucullatus desert N A,B,D Colubridae Psammophis schokari desert D A,B,D,K Colubridae Malpolon monspessulanus generalist D B,D,K,O Colubridae Telescopus fallax generalist N D,K,O Viperidae Vipera palaestinae generalist N A,B,D,K,O

Table 24: Amphibian species checklist of Nizzanim sands and environs. Family Species Category Habitat(s) Bufonidae Bufo viridis generalist A,B,D,K Pelobatidae Pelobates syriacus generalist K Ranidae Rana ridibunda aquatic K Hylidae Hyla savignyi generalist D,K Salamandridae Triturus vittatus aquatic K

This checklist of herpetofaunal species occurring in Nizzanim sands nature reserve and environs is based on the combined databases of this study and additional observational data (Shacham, unpublished) collected by the author during the years 1996-2009. Definitions and explanations for categories in Tables 23 & 24: • Species in bold type were recorded in the database of this study. • Category – grouped with reference to ecological groups as defined within this project, either "generalist" (of Mediterranean distribution or ecologically opportunistic) or "desert" (of Saharan or Saharo-Arabian distribution, or strongly associated with sand dunes). In Table 24 appears also "aquatic", relevant for some amphibians. • Activity – with regards to diel cycle, D = diurnal, N = nocturnal, D/N = diurnal-nocturnal, F = fossorial. • Habitat(s) – known habitat types where the species occurs; A = active dunes, B = semistable dunes, D = stabilized dunes, K = Kurkar sandstone and hamra (red sand) hills, O = opportunistic/commensally found near human dwellings or agro-fields.

134 Boaz Shacham – PhD dissertation

135 Boaz Shacham – PhD dissertation

כלל הנתונים שנאספו עד כה מצביעים על כך המיניםש מהסוג (שנונית Acanthodactylus הם) הם) האינדיקאטורים הטובים היעילים, והחסכוניים ביותר לזוחלים בחולות ניצנים ואולי גם באתרים באתרים גם ואולי ניצנים בחולות לזוחלים ביותר והחסכוניים היעילים, הטובים אחרים אך, יש לבחון זאת בכל אתר לגופו אני. מציע להרחיב את היריעה לגבי המינים הללו באמצעות באמצעות הללו המינים לגבי היריעה את להרחיב מציע אני. לגופו אתר בכל זאת לבחון יש אך, אחרים לכידות בשעות היום במלכודות, ובחלקות ותהקיימ בפרויקט ובכך, להשיג הבנה טובה של דמוגרפיה, דמוגרפיה של טובה הבנה להשיג ובכך, בפרויקט ותהקיימ ובחלקות במלכודות, היום בשעות לכידו ת אורחות חיים ותגובות למשטרי הממשק של הלטאות . . הלטאות של הממשק למשטרי ותגובות חיים אורחות למרות שמוקדם מדי להכריז על הצלחה או על כשלון בשיקום חברות מינים פסמופילים על דיונות דיונות על פסמופילים מינים חברות בשיקום כשלון על או הצלחה על להכריז מדי שמוקדם למרו ת מיוצבות לאחר ממשק הסרת צומח חלקית התוצאות, בכללותן מעודדות המסלולים. העתידיים של של העתידיים המסלולים. מעודדות בכללותן התוצאות, חלקית צומח הסרת ממשק לאחר מיוצבו ת חלקות המחקר תלויים בקבלת החלטות דינאמית והמשך ניטור של כל הקבוצות הטקסונומיות בפרויקט זה ניתן. לראות סימני סוקצסיה שחלק מהחלקות המטופלות מכאן, שיש צורך בפעולות בפעולות צורך שיש מכאן, המטופלות מהחלקות שחלק סוקצסיה סימני לראות ניתן. זה בפרוי קט ממשק חוזרות מנהלי. הפרויקט בוחנים כעת אפשרויות חלופיות לממשק הצומח לדוגמה, רעיית רעיית לדוגמה, הצומח לממשק חלופיות אפשרויות כעת בוחנים הפרויקט מנהלי. חוזרות ממשק גמלים . . גמלים המסקנות המתודולוגיות של עבודתי אינן נופלות בחשיבותן מהמסקנות הספציפיות לגבי חברות חברות לגבי הספציפיות מהמסקנות בחשיבותן נופלות אינן עבודתי של הזוחלים והשפעות הממשק בניצנים לקבלת. התמונה הרחבה ביותר האפשרית חובה, להשתמש להשתמש חובה, האפשרית ביותר הרחבה התמונה לקבלת. בניצנים הממשק והשפעות הזוחלי ם בשיטות דיגום מרובות לזוחלים אף. שיטה אינה מכסה לבדה את כל מצאי המינים של חולות החוף, החוף חולות של המינים מצאי כל את לבדה מכסה אינה שיטה אף. לזוחלים מרובות דיגום בשיטות ואף מין אינו נותן בדול את התמונה המלאה של השפעות הממשק על החברות אחדים. מהמינים מהמינים אחדים. החברות על הממשק השפעות של המלאה התמונה את בדול נותן אינו מין ואף הנדירים הם בעלי חשיבות לשמירת הטבע ואין, להתעלם מהם דוגמת, כוח (אפור Varanus griseus) שהופיע ב 1 בלבד% מהדגימות שניתחתי נחשים. אינם נלכדים בדרך כלל במלכודות נפילה אך, אך, נפילה במלכודות כלל בדרך נלכדים אינם נחשים. שניתחתי מהדגימות בלבד% מופיעים לעתים קרובות ביותר שביליב הטשטוש שבילי. טשטוש מודדים רמת פעילות אך, אינם אינם אך, פעילות רמת מודדים טשטוש שבילי. הטשטוש שביליב ביותר קרובות לעתים מופיעים מספקים מידע על מורפולוגיה ודמוגרפיה שניתן לקבל בעזרת מלכודות נפילה המלכודות. ושבילי ושבילי המלכודות. נפילה מלכודות בעזרת לקבל שניתן ודמוגרפיה מורפולוגיה על מידע מספקי ם הטשטוש במחקר שלי כוונו למינים פעילי לילה בלבד מכאן, החשיבות הרבה של חתכי התצפיות התצפיות חתכי של הרבה החשיבות מכאן, בלבד לילה פעילי למינים כוונו שלי במחקר הטשטוש בלטאות היומיות לפיכך. שיטות, הדיגום ונותהש בהן השתמשתי השלימו זו את זו כשכל, אחת אחת כשכל, זו את זו השלימו השתמשתי בהן ונותהש הדיגום שיטות, לפיכך. היומיות בלטאות תורמת להבנת חברות הזוחלים ולמעקב אחר השפעות הממשק על ציר הזמן השיטה. שבה מיזגתי את את מיזגתי שבה השיטה. הזמן ציר על הממשק השפעות אחר ולמעקב הזוחלים חברות להבנת תורמת בסיסי הנתונים למטריצה מאוחדת לצורך ניתוח ממדי-רב היא שימושית ביותר לאינטגרציה של כל כל של לאינטגרציה ביותר שימושית היא ממדי-רב ניתוח לצורך מאוחדת למטריצה הנתונים בסיסי המידע אך, אין להתעלם מהיתרונות של ניתוח כל השיט בפני עצמה אחרת, עלולים לפספס חלק ניכר ניכר חלק לפספס עלולים אחרת, עצמה בפני השיט כל ניתוח של מהיתרונות להתעלם אין אך, המידע מן הרזולוציה שהושגה בעבודה קשה בשדה . . בשדה קשה בעבודה שהושגה הרזולוציה מן יש להמשיך ולנטר את הזוחלים בפרויקט זה בשנים הבאות אני; מאמין שהשיטות והשאלות של של והשאלות שהשיטות מאמין אני; הבאות בשנים זה בפרויקט הזוחלים את ולנטר להמשיך י ש המחקר ימשיכו להתפתח עם הפרויקט ויחד עם נתוני הקבוצות הטקסונומיות האחרות יספקו יספקו האחרות תשובות להכוונת ותמדיני שימור בחולות ניצנים ובאתרים אחרים . . אחרים ובאתרים ניצנים בחולות שימור ותמדיני להכוונת תשובות

מילות מפתח חולות: החוף זוחלים; ממשק; ניהול; הסרת; צומח שנתי-רב התייצבות; חולות דיונות; דיונות; חולות התייצבות; שנתי-רב צומח הסרת; ניהול; ממשק; זוחלים; החוף חולות: פעילות דיונות; למחצה-מיוצבות דיונות; מיוצבות מינם; מתמחים מדבריים מינים; גנרליסטים; גנרליסטים מינים; מדבריים מתמחים מינם; מיוצבות דיונות; למחצה-מיוצבות דיונות; פעילות פסמופילים ים; תיכוניים- . . תיכוניים- ים; פסמופילים

Boaz Shacham – PhD dissertation ט 136

במידה מסוימת ותבדיונ מיוצבות עושר.למחצה- המינים הגבוה ביותר נמצא בדיונות מיוצבות אולם, אולם, מיוצבות בדיונות נמצא ביותר הגבוה המינים עושר.למחצה- מיוצבות ותבדיונ מסוימת במידה לכך אחראית המגמה של עליה בנוכחות מינים (גנרליסטים תיכוניים-ים עם) עליה בהתייצבות בהתייצבות עליה עם) תיכוניים-ים (גנרליסטים מינים בנוכחות עליה של המגמה אחראית לכך הדיונות החברות. בדיונות השונות הובחנו היטב בניתוחים ממדיים-הרב מסוג PCA המשתנה. המשתנה. הסביבתי המשמעותי ביותר בירשהס חלק גדול מהשונות בין החברות היה אחוז כיסוי צומח רב שנתי- שנתי- רב צומח כיסוי אחוז היה החברות בין מהשונות גדול חלק בירשהס ביותר המשמעותי הסביבתי כללי נמצאה, קורלציה-אוטו גבוהה בינו לבין המשתנים הסביבתיים האחרים (שבחנתי אחוזי כיסוי כיסוי אחוזי (שבחנתי האחרים הסביבתיים המשתנים לבין בינו גבוהה קורלציה-אוטו נמצאה, כללי של חיים-צורות שונות של הצומח מדד; חומר אורגני בקרקע ). ). בקרקע אורגני חומר מדד; הצומח של שונות חיים-צורות של הנתונים של החלקות המטופלות הראו עבור, חלק ממיני הזוחלים מגמות, דומות לאלו שנמצאו שנמצאו לאלו דומות מגמות, הזוחלים ממיני חלק עבור, הראו המטופלות החלקות של הנתונים בדיונות (טבעיות לא מטופלות למחצה-מיוצבות) או פעילות למשל. שכיחות, נחושית חולות בחלקות בחלקות חולות נחושית שכיחות, למשל. פעילות או למחצה-מיוצבות) מטופלות לא (טבעיות בדיונות מטופלות ירדה לרמות דומות למה שנמצא בחלקות בעלות כיסוי נמוך טבעי עם. זאת הרכב, המינים המינים הרכב, זאת עם. טבעי נמוך כיסוי בעלות בחלקות שנמצא למה דומות לרמות ירדה מטופלות במרבית הדיונות המטופלות דומה יותר להרכב (המקורי )ממשקי-טרום ועודו, רחוק מן היעדים היעדים מן רחוק ועודו, )ממשקי-טרום (המקורי להרכב יותר דומה המטופלות הדיונות במרבית אליהם הממשק שאף להביא אותם בניתוחים. מסוג PCA נמצאה חפיפה רבה בפיזור של החברות החברות של בפיזור רבה חפיפה נמצאה בדיונות (המטופלות בכל משטרי הממשק הן) עם דיונות המצב (המקורי בקורת והן) עם דיונות היעד היעד דיונות עם והן) בקורת (המקורי המצב דיונות עם הן) הממשק משטרי בכל (המטופלות בדיונות יחוס( שלהן) המסלולים. של משטרי MDA ו MDB נראו תחילה מתקרבים לכיוון היעדים בניתוח בניתוח היעדים לכיוון מתקרבים תחילה נראו מסוג PCR אך, בהמשך חזרו לרמות של המצב ממשקי-הטרום משטר. MCA הראה את התוצאות התוצאות את הראה המבטיחות ביותר לעבר היעד באותו ניתוח אך, אף אחד מהמשטרים לא השיג את היעדים במלואם במלואם היעדים את השיג לא מהמשטרים אחד אף אך, ניתוח באותו היעד לעבר ביותר המבטיחות מבחינת חברות הזוחלים שהתקבלו . . שהתקבלו הזוחלים חברות מבחינת

הגורם העיקרי אשר מנע מחלקות MDA ו MDB להגיע לחברות עדהי בתקופה שמכסה המחקר המחקר שמכסה בתקופה עדהי לחברות להגיע שלי הוא הכישלון של שנונית חולות להתנחל בחלקות אלו כשל. זה נובע ככל הנראה מגורמים פיזיים פיזיים מגורמים הנראה ככל נובע זה כשל. אלו בחלקות להתנחל חולות שנונית של הכישלון הוא שלי אשר חוצצים בין אוכלוסיות מקור של מין זה לבין חלקות MDA ו MDB ניסיתי. באפן ניסיוני ניסיוני באפן ניסיתי. להעתיק לטאות ממין (זה 49 חיות מדיונות) מקור לשלוש חלקות מטופלות בשלהי חודש אוקטובר אוקטובר חודש בשלהי מטופלות חלקות לשלוש מקור מדיונות) חיות 2007 אך, הן לא ביססו אוכלוסיות במקום אני. מציע לחזור על הניסיון להעתיק שנונית חולות חולות שנונית להעתיק הניסיון על לחזור מציע אני. במקום אוכלוסיות ביססו לא הן אך, לחלקות אלו בקנה, מידה יותר גדול ועם תכנון קפדני יותר ובתנאים, מיטביים להשתמש, בשיטות בשיטות להשתמש, מיטביים ובתנאים, יותר קפדני תכנון ועם גדול יותר מידה בקנה, אלו לחלקות לאקלום הלטאות המועתקות . . המועתקות הלטאות לאקלום ניתוח של שכיחות פציעות זנב ומדדי מצב גופני בשני מיני הלטאות הכי נלכדים נחושית, חולות חולות נחושית, נלכדים הכי הלטאות מיני בשני גופני מצב ומדדי זנב פציעות שכיחות של ניתוח וישימונית מצויה מגלה, מגמות של ירידה בשכיחות פציעות זנב במקביל לירידה במצב גופני עם עליה עליה עם גופני במצב לירידה במקביל זנב פציעות בשכיחות ירידה של מגמות מגלה, מצויה וישימוני ת בהתייצבות הדיונות בחלקות הלא מטופלות מגמות. אלו משתקפות גם בנתונים של החלקות החלקות של בנתונים גם משתקפות אלו מגמות. מטופלות הלא בחלקות הדיונות בהתייצבו ת (המטופלות בכל משטרי הממשק –) עליה בשכיחות תפציעו זנב עם עליה במצב הגופני לאחר טיפול טיפול לאחר הגופני במצב עליה עם זנב תפציעו בשכיחות עליה –) הממשק משטרי בכל (המטופלות הממשק תוצאות. אלו מרמזות על גרדיאנטים מתחלפים היוצרים, trade-off של, סכנת טריפה טריפה סכנת של, המתבטאת( בפציעות זנב ושל) תחרות על (משאבים המתבטאת במצב גופני במקביל) לגרדיאנט של של לגרדיאנט במקביל) גופני במצב המתבטאת (משאבים על תחרות ושל) זנב בפציעות המתבטאת( התייצבות הדיונות אני. מציע לחקור יותר לעומק את התופעות לוהל על, מנת לברר האם המגמות המגמות האם לברר מנת על, לוהל התופעות את לעומק יותר לחקור מציע אני. הדיונות התייצבו ת נעשות מובהקות סטטיסטית במדגם גדול יותר תוצר. לוואי של מחקר כזה ישפר את הבנתנו על על הבנתנו את ישפר כזה מחקר של לוואי תוצר. יותר גדול במדגם סטטיסטית מובהקות נעשות אורחות חייהם של המינים הללו ובפוטנציה נקבל ראינדיקאטו-ביו להשפעות הממשק באמצעות באמצעות הממשק להשפעות ראינדיקאטו-ביו נקבל ובפוטנציה הללו המינים של חייהם אורחות תגובות .גופניות .גופניות תגובו ת

Boaz Shacham – PhD dissertation ח 137

נחלקו לשלוש :קטגוריות דיונות (פעילות בלתי =מיוצבות active dunes עד, 10 כיסוי% צומח רב רב צומח כיסוי% שנתי, 3 )חלקות דיונות; מיוצבות (למחצה- semistable dunes בערך, 25 כיסוי% , 6 )חלקות ודיונות; ודיונות; )חלקות (מיוצבות stabilized dunes מעל, 40 כיסוי% , 3 ).חלקות דיונות מטופלות בהן, נעשתה התערבות התערבות נעשתה בהן, מטופלות דיונות ).חלקות ממשקית נחלקו, לשלוש (קטגוריות משטרי ממשק): MCA דיונות, למחצה-מיוצבות שטופלו לרמת לרמת שטופלו למחצה-מיוצבות דיונות, כיסוי (פעיל 4 )חלקות ; MDA דיונות, מיוצבות שטופלו לרמת כיסוי (פעיל 3 )חלקות ; MDB דיונות, דיונות, מיוצבות שטופלו לרמת כיסוי (למחצה-מיוצב 3 חלקות הממשק). בוצע באמצעים מכאניים במרץ במרץ מכאניים באמצעים בוצע הממשק). חלקות 2005 בשבע חלקות (מחקר כל חלקות MDB ,MDA ואחת של MCA ובנובמבר) 2005 ( שלוש חלקות חלקות שלוש ( MCA )הנותרות לאחר, איסוף נתוני בסיס לפני פעולות הממשק בכל. מחנה שטח כל, חלקה נדגמה נדגמה חלקה כל, שטח מחנה בכל. הממשק פעולות לפני בסיס נתוני איסוף לאחר, )הנותרות בשני לילות ושני בקרים ברצף על, ידי צוותים (קטנים 3-2 )אנשים , שונעואשר על ציודם ברכבי שטח, שטח ברכבי על ציודם שונעואשר , )אנשים תוך הקפדה על נסיעה רק דרכיםב קיימות . . קיימות דרכיםב רק נסיעה על הקפדה תוך

מספר שיטות ויושמ לדיגום [הזוחלים: 1 מלכודות] נפילה, 10 (דליים פלסטיק בנפח, 10 ליטר בכל) בכל) ליטר חלקה קבורים עד שפתם בחול שנפתחו, סמוך לשקיעה ונבדקו השכם בבוקר ותוגברו, על ידי 30 כוסות (קטנות פלסטיק, 500 ק"סמ בכל) חלקה אשר שימשו את צוותי מחקר חסרי (החוליות זוחלים זוחלים (החוליות חסרי מחקר צוותי את שימשו אשר חלקה בכל) ק"סמ שנלכדו במקרה םאצל הועברו למדידה ולשחרור בידי צוותי )הזוחלים [; 2 שבילי] טשטוש אשר, אשר, טשטוש שבילי] נמחקו בסמוך לשקיעה ונבדקו עם אור ראשון שני, (שבילים 90 מטר כל אחד בכל) חלקה [; 3 חתכי] חתכי] הליכה לתצפית בלטאות יומיות שנערכו, בשעות הבוקר המאוחרות כשפעילות הלטאות בשיאה – – בשיאה הלטאות כשפעילות המאוחרות הבוקר בשעות שנערכו, יומיות בלטאות לתצפית הליכה נרשמו כל הלטאות שנצפו מןבז הליכה בארבעה (חתכים 90 מטר כל אחד בכל) חלקה [; 4 כל] כל] הזוחלים שנצפו באפן ("אקראי מזדמנים נרשמו") [; 5 זוחלים] שנלכדו זוהו לגבי מין וזוויג נשקלו, נשקלו, וזוויג מין לגבי זוהו שנלכדו זוחלים] (ונמדדו אורך גוף )וזנב סומנו, לצורך זיהוי פרטני עתידי ושוחררו שיטות. סטטיסטיות משתניות-חד משתניות-חד סטטיסטיות שיטות. ושוחררו עתידי פרטני זיהוי לצורך סומנו, )וזנב גוף אורך (ונמדדו (ANOVA, Chi2 Test, Fisher's Exact Test, Student's t-Test (משתניות-ורב) = RDA Redundancy Analysis, PCA = Principal Component Analysis, PCR = Principal Response Curve שימשו) אותי לניתוח התוצאות הנתונים. שנאספו בשיטות השונות שתוארו לעיל נותחו קודם קודם נותחו לעיל שתוארו השונות בשיטות שנאספו הנתונים. התוצאות לניתוח אותי שימשו) בנפרד כך-אחר, נותחו כבסיס נתונים (מאוחד לאחר המרה ותקנון מתאימים ). ). מתאימים ותקנון המרה לאחר (מאוחד נתונים כבסיס נותחו כך-אחר, בנפרד נתוני החלקות הלא (מטופלות יחוס + בקורת הראו) כי בדיונות ,פעילות בולטים בעיקר שלושה שלושה בעיקר בולטים ,פעילות כי בדיונות הראו) בקורת + יחוס (מטופלות הלא החלקות נתוני מיני לטאות (מדבריים שנונית חולות Acanthodactylus scutellatus נחושית, חולות Sphenops sepsoides וישימונית מצויה Stenodactylus sthenodactylus ) אשר, מוגבלים בחבל תיכוני-הים תיכוני-הים בחבל מוגבלים אשר, ) לבתי גידול חוליים לאורך החוף בדיונות; למחצה-מיוצבות נוספים שני מיני לטאות מתפוצה -ים מתפוצה לטאות מיני שני נוספים למחצה-מיוצבות בדיונות; החוף לאורך חוליים גידול לבתי (תיכונית שנונית שפלה A. schreiberi ונחושית עינונית Chalcides ocellatus ) בדיונות; מיוצבות מיוצבות בדיונות; ) נוספים שני מיני לטאות תיכוניים-ים (נוספים חומט םפסי Mabuya vittata וחומט גמד Ablepharus rueppellii ואילו) שנונית החולות נעלמת כליל מהחברה הלטאה. פעילת היום שנונית חולות מאפיינת מאפיינת חולות שנונית היום פעילת הלטאה. מהחברה כליל נעלמת החולות שנונית ואילו) את הדיונות הפעילות בעוד, שנונית שפלה מאפיינת את הדיונות ושתיהן,המיוצבות מופיעות כשותפות כשותפות מופיעות ושתיהן,המיוצבות הדיונות את מאפיינת שפלה שנונית בעוד, הפעילות הדיונות את

Boaz Shacham – PhD dissertation ז138

תקציר

חולות החוף הים תיכוני של ישראל ויםמהו אקוסיסטמה תייחודי ברמה האזורית והעולמית כאשר, כאשר, והעולמית האזורית ברמה תייחודי אקוסיסטמה ויםמהו ישראל של תיכוני הים החוף חולות הקרקע היובשנית האאולית מאשפרת חדירתם של מיני צומח וחי רבים ממוצא מדברי סהרתי למרות למרות סהרתי מדברי ממוצא רבים וחי צומח מיני של חדירתם מאשפרת האאולית היובשנית הקרקע האקלים הממוזג מינים. מינים-ותת אנדמיים רבים בעיקר, של צמחים וחסרי חוליות התפתחו, בבתי בבתי התפתחו, חוליות וחסרי צמחים של בעיקר, רבים אנדמיים מינים-ותת מינים. הממוזג האקלי ם הגידול שלאורך החוף במרוצת. ששת םהעשורי האחרונים חולות, החוף של ישראל עברו תנופת פיתוח פיתוח תנופת עברו ישראל של החוף חולות, האחרונים םהעשורי ששת במרוצת. החוף שלאורך הגידול אדירה שהביאה, לצמצום שטחי בתי הגידול הבלתי מופרים -מ 462 ר"קמ בתחילת המאה העשרים העשרים המאה בתחילת ר"קמ לכ - 250 ר"קמ בימינו שפחות, ממחציתם מוגנים תסטטוטורי מתוך. האיומים הרבים המרחפים מעל מעל המרחפים הרבים האיומים מתוך. תסטטוטורי מוגנים ממחציתם שפחות, בימינו ר"קמ המשך הישרדות חולות אלה החמור, ביותר הוא לככ הנראה התייצבות הדיונות הגורם. המרכזי המרכזי הגורם. הדיונות התייצבות הנראה לככ הוא ביותר החמור, אלה חולות הישרדות המשך להתייצבות החולות הוא הפסקתם של "חקלאות מוואסי ורעיית" צאן המסורתיות מאז שנות שנות מאז המסורתיות צאן ורעיית" מוואסי "חקלאות של הפסקתם הוא החולות להתייצבו ת החמישים של המאה הקודמת שבעבר, שמרו על פעילות הדיונות ניתוח. תצלומי אוויר של חולות חולות של אוויר תצלומי ניתוח. הדיונות פעילות על שמרו שבעבר, הקודמת המאה של החמישים ניצנים בדרום, מישור החוף הראה, שינויים דרסטיים בכיסוי מחהצו של שטח המחקר במהלך במהלך המחקר שטח של מחהצו בכיסוי דרסטיים שינויים הראה, החוף מישור בדרום, ניצנים ארבעים השנה האחרונות עם, הגדלה של 82 בשטחי% הדיונות המיוצבות במקביל לירידה של %37 בשטחי הדיונות (הפעילות בלתי מיוצבות לפי). המגמות הקיימות של שינויים בכיסוי הצומח כל, כל, הצומח בכיסוי שינויים של הקיימות המגמות לפי). מיוצבות בלתי (הפעילות הדיונות בשטחי השטח בחולות ניצנים יהפוך לחולות (מיוצבים מעל 60 כיסוי% תוך) כשלושים שנה אלא, אם כן כן אם אלא, שנה כשלושים תוך) כיסוי% תינקטנה פעולות ממשק פעיל התייצבות. החולות מביאה להכחדה מקומית של מינים מדבריים מדבריים מינים של מקומית להכחדה מביאה החולות התייצבות. פעיל ממשק פעולות תינקטנה מתמחים" והחלפתם" על ידי מינים ים "תיכוניים גנרליסטים הסרת". צומח חלקית הצליחה בעבר בעבר הצליחה חלקית צומח הסרת". גנרליסטים "תיכוניים ים מינים ידי על והחלפתם" מתמחים" לשקם אוכלוסיות מכרסמים (פסמופילים מתמחי חול במרכז) מישור (החוף פארק )השרון עתוכ, עתוכ, )השרון פארק (החוף מישור במרכז) חול מתמחי (פסמופילים מכרסמים אוכלוסיות ל שקם בוחנים זאת כפתרון מעשי לניהול השטח בניצנים . . בניצנים השטח לניהול מעשי כפתרון זאת בוחני ם בחיבור זה אציג את תוצאות מחקרי לגבי ההשפעות של הסרת צומח חלקית מדיונות מיוצבות על על מיוצבות מדיונות חלקית צומח הסרת של ההשפעות לגבי מחקרי תוצאות את אציג זה בחיבור חברות הזוחלים בחולות ניצנים עבדתי. במסגרת פרויקט מחקר ארוך טווח- (תחומי-רב צוותים צוותים (תחומי-רב טווח- ארוך מחקר פרויקט במסגרת עבדתי. ניצנים בחולות הזוחלים חברות אחרים חוקרים חסרי חוליות מכרסמים, )וצמחים עדושי, המרכזי לבחון כלים ממשקיים לשימור בר- בר לשימור ממשקיים כלים לבחון המרכזי עדושי, )וצמחים מכרסמים, חוליות חסרי חוקרים אחרים קיימא של הרכיבים הביוטיים של חולות החוף במחקר. שלי היו שלוש מטרות [מרכזיות: 1 תיאור] תיאור] חברות הזוחלים הקיימות על סוגי הדיונות הטבעיים בניצנים [; 2 תיאור] ההשפעות של הסרת צומח צומח הסרת של ההשפעות תיאור] חלקית על חברות הזוחלים [ו; 3 להסיק] מסקנות שיותמע ותפישתיות ולגבש המלצות לגבי ניטור ניטור לגבי המלצות ולגבש ותפישתיות שיותמע מסקנות להסיק] ומחקר של זוחלים בעתיד בניצנים, ובחולות בכלל המטרה. השלישית כללה השוואה בין מספר משטרי משטרי מספר בין השוואה כללה השלישית המטרה. בכלל ובחולות בניצנים, בעתיד זוחלים של ומחקר ממשק צומח שונים זיהוי, מיני אינדיקטורים יעילים מקרב הזוחלים ואינטגרציה, וניתוח של השיטות השיטות של וניתוח ואינטגרציה, הזוחלים מקרב יעילים השונות בהן אספתי את הנתונים . . הנתונים את אספתי בהן השונות

הנתונים צגיםהמו כאן נאספו מחודש מאי 2004 ועד ספטמבר 2008 ( )כולל במהלך, מחנות שטח שטח מחנות במהלך, )כולל ( שנערכו לפחות בשתי עונות שונות מדי שנה הניתוח. כולל עשרים ושתיים חלקות מחקר בנות 4000 ר"מ האחת משלושה, טיפוסי דיונות טבעיות ושלושה טיפוסי דיונות מטופלות לפחות, שלוש חזרות חזרות שלוש לפחות, מטופלות דיונות טיפוסי ושלושה טבעיות דיונות טיפוסי משלושה, האחת ר"מ )חלקות( מערך.ריהקטגולכל הניסוי נבנה לפי מודל M-BARCI שבו, ריבוי (חזרות Multiple של) של) מידע (לפני Before (ואחרי) After התערבות) ממשקית בחלקות, (יחוס" " Reference ) בקורת", " בקורת", ) (Control (התערבות"ו) " Intervention חלקות). טבעיות ללא, התערבות (ממשקית יחוס ובקורת ) ) ובקורת יחוס (ממשקית התערבות ללא, טבעיות חלקות).

Boaz Shacham – PhD dissertation ו139

רשימת האיורים והט )המשך(בלאות איור 27 ניתוח: ממדי-רב של הנתונים שנאספו בשנת 2004 ...... 71 איור 28 ניתוח: ממדי-רב של הנתונים שנאספו בשנת 2005 ...... 72 איור 29 ניתוח: ממדי-רב של הנתונים שנאספו בשנת 2006 ...... 73 איור 30 ניתוח: ממדי-רב של הנתונים שנאספו בשנת 2007 ...... 74 איור 31 ניתוח: ממדי-רב של הנתונים שנאספו בשנת 2008 ...... 75 איור 32 ניתוח: סדרת (זמן time series של) מסלולי החלקות בעקבות הממשק ...... 76 איור 33 הנוסחה: לחישוב מדד מצב גופני (יחסי BI) ...... 77 איור 34 שכיחות: פציעות זנב בנחושית (חולות S. sepsoides) ...... 78 טבלה 13 שכיחות: פציעות זנב בנחושית (חולות S. sepsoides) ...... 79 טבלה 14 רמות: מובהקות פציעות נבז בנחושית (חולות S. sepsoides ..) ...... 79 איור 35 מדד: מצב גופני בנחושית (חולות S. sepsoides בסוגי) החלקות השונים ...... 80 טבלה 15 רמות: מובהקות מדד מצב גופני בנחושית (חולות S. sepsoides ..) ...... 80 איור 36 פרטים: לדוגמה של נחושית (חולות S. sepsoides) ...... 81 איור 37 תשכיחו: פציעות זנב בישימונית (מצויה S. sthenodactylus) ...... 82 טבלה 16 שכיחות: פציעות זנב בישימונית (מצויה S. sthenodactylus) ...... 83 הטבל 17 רמות: מובהקות פציעות זנב בישימונית (מצויה S. sthenodactylus ...... ) ...... 83 איור 38 מדד: מצב גופני בישימונית (מצויה S. sthenodactylus בסוגי) החלקות השונים ...... 84 טבלה 18 רמות: מובהקות מדד מצב גופני בישימונית (מצויה S. sthenodactylus) ...... 84 איור 39 פרט: לדוגמה של ישימונית (מצויה S. sthenodactylus) ...... 85 בלהט 19 סך: הכל תצפיות בלטאות מהסוג (שנונית Acanthodactylus ...... ) ...... 87 איור 40 כמות: תצפיות בממוצע בלטאות מהסוג (שנונית Acanthodactylus)...... 87 להטב 20 כמות: תצפיות בממוצע בלטאות מהסוג (שנונית Acanthodactylus)...... 88 טבלה 21 רמות: מובהקות תצפיות בשנונית (חולות A. scutellatus) ...... 88 טבלה 22 רמות: מובהקות תצפיות בשנונית (שפלה A. schreiberi) ...... 88 איור 41 גרף: שפע/שכיחות תצפיות בלטאות מהסוג (שנונית Acanthodactylus ...... ) ...... 90 איור 42 פרטים: לדוגמה של שנונית (חולות A. scutellatus) ...... 91 איור 43 פרטים: לדוגמה של שנונית (שפלה A. schreiberi) ...... 91 איור 44 קשר: משוער בין מגוון מינים לבין התייצבות הדיונות ...... 93 איור 45 החלפה: משוערת בין לחץ טריפה לבין תחרות על משאבים ...... 102 טבלה 23 רשימת: מצאי מיני זוחלים בחולות ניצנים וסביבתם ...... 133 טבלה 23 רשימת: מצאי מיני דוחיים בחולות ניצנים וסביבתם ...... 134

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רשימת האיורים והטבלאות איור 1: דיונה פעילה ...... 27 7 2 איור 2 : למחצה-תמיוצבדיונה ...... 28 איור 1 : מיוצבתדיונה ...... 29 טבלה 1 רשימת: חלקות המחקר בעבודה .....זו ...... 30 איור 4 מפה: של אתר המחקר בחולות ניצנים ...... 31 איור 5 דחפור: ופעב ...לה ...... 33 איור 6: סימון החלקות לממשק ...... 33 איור 7 פסולת: מפעולת הסרת ..הצומח ...... 34 איור 8 תצלום: אווירי של חלקות ..ממשק ...... 34 טבלה 2 תכונות: המידע שנאסף בשיטות הדיגום השונות ...... 37 איור 9 תצורה: מרחבית של חלקת מחקר ופריסת שיטות ...הדיגום ...... 38 איור 10a חתך: סכמאטי של מלכודת נפילה מבט, .צד ...... 39 איור 10b חתך: סכמאטי של מלכודת נפילה מבט, .על ...... 39 איור 11 תצורה: מרחבית של מערך מלכודות נפילה ומספורן...... 40 איור 12: מלכודת נפילה מכוסה...... 40 איור 13: חשיפת מלכודת נפילה ...... 41 1 4 איור 14: שביל טשטוש...... 41 טבלה 3: סיכום המינים שנמצאו ...... 46 איור 15 שכיחות: יחסית של מינים נפוצים ...... 47 טבלה 4 כמות: תצפיות ועושר מינים .ממוצעים ...... 49 טבלה 5 כמות: תצפיות ועושר מינים ממוצעים בסיכום כל השיטות ...... 50 איור 16 מדדי: עושר מינים ממוצעים ...... 51 איור 17 פרופורציית: מינים מתמחי מדבר בממוצע ...... 52 איור 18 ניתוח: ממדי-רב של החלקות מטופלות-הלא ...... 54 איור 19 נתו: נים עונתיים : אביב ...... 57 איור 20: נתונים עונתיים : קיץ ...... 57 איור 21: נתונים עונתיים ...... וסתי: ...... 58 טבלה 6 כמות: תצפיות בממוצע בלטאות מהסוג (שנונית Acanthodactylus .) ...... 59 איור 22 כמות: תצפיות בממוצע בלטאות מהסוג (שנונית Acanthodactylus)...... 59 טבלה 7 סך: הכל תצפיות בלטאות מהסוג (שנונית Acanthodactylus ...... ) ...... 60 איור 23 גרף: שפע/שכיחות תצפיות בלטאות מהסוג (שנונית Acanthodactylus)...... 61 איור 24 מדדי: עושר מינים ממוצעים בסוגי החלקות השונים ...... 65 איור 25 פרופורציית: מינים מתמחי מדבר בממוצע בסוגי החלקות השונים ...... 66 טבלה 8 מדדי: עושר מינים ממוצעים בסוגי החלקות השונים ...... 66 טבלה 9 רמות: מובהקות של עושר מינים כללי ...... 67 טבלה 10 רמות: מובהקות של עושר מינים סטיםגנרלי ...... 67 טבלה 11 רמות: מובהקות של עושר מינים מתמחי מדבר ...... 67 טבלה 12 רמות: מובהקות לש פרופורציית מינים מתמחי מדבר ...... 68 איור 26 ניתוח: ממדי-רב של כל סוגי החלקות לפני ואחרי הממשק ...... 69

Boaz Shacham – PhD dissertation ד 141

תוכן עניינים

..קצירת ..…………….……………………………………………………….……………………………… 4 4 מבוא...……………….………………………………………………….…………………….…..………… 9 9 אקוסיטמות של דיונות חופיות...... …………………………………….….………… 9 9 חולות מישור חוףה של ישראל...... ……..…………………………………….……… 12 12 הבחירה בניצנים כמקרה מבחן...... ……………………………………..….…… 15 15 פרויקט ניצנים...... …………………………………………………………………… 19 19 שאלות המחקר ...... 23 23 שאלות המחקר...... 23 23 תוצרי עבודה ...... זו ...... 23 ותהיפותז ותחזיות המחקר...... 24 24 שיטות.……………………………………………………………………………………….……………… 26 26 אתר ...המחקר ……..……………………………………………………………………… 26 26 מערך הניסוי...... ………………………………………………… 29 29 שיטות לדיגום הזוחלים.…………………………….……………………………………… 35 35 שיטות לעיבוד וניתוח ....הנתונים ...... …………………………………..……………… 42 42 תוצאות 'א חברות: הזוחלים בחולות ניצנים ..……………………….………………………..…..…………… 45 45 הרכב המינים בסוגי הדיונות השונים..…….………………………………….…..………… 45 45 השפעת כיסוי הצומח על חברות מיני הזוחלים.……………………….……………………… 53 53 השפעות עונתיות על פעילות ושפע הזוחלים..………………………………………………… 55 55 דגמים שנצפו בפעילות הלטאות היומיות...... …………………………..…………… 59 59 תוצאות 'ב תגובת: הזוחלים לפעולות הממשק ..………………………………………..……………………… 62 62 שינויים בחברות הזוחלים בעקבות פעולות הממשק….…………...….……………..………… 62 62 מסלול השפעות הממשק על ציר הזמן...……………………………..…..………………… 70 70 השפעות הממשק על המצב הגופני בלטאות………………………………….……………… 77 77 תגובת לטאות מהסוג (שנונית Acanthodactylus לממשק) ……..…………………………… 85 85 דיון ומסקנות.………………………………………………………..……...……….……………………… 92 92 חברות הזוחלים בחולות ניצנים …………………………..………………………………… 92 92 תגובת חברות הזוחלים לפעולות ממשק בחולות ניצנים..…………………..………………… 96 96 השלכות לגבי ממשק וניטור...... ………………………….……………………… 103 103 מכשולים פוטנציאליים כיצד: מתמודד עימם פרויקט ?ניצנים ...... ….……………… 111 111 תקציר המסקנות מחולות ניצנים.…………………………………………………..……… 113 113 תקציר ההמלצות לגבי ניטור זוחלים בחולות.…………………………………………..…… 114 114 שאלות מחקר חדשות העולות מעבודה זו……………………………………….…………… 115 115 ביבליוגרפיה.……………………………………………………………….………………………….…… 117 117 נספח I שחזור: אקולוגי – הגדרות אסטרטגיות, בעיות, פוטנציאליות תכנון, ...…… ……………………………… 128 128 הגדרת מונחים בסיסיים..….……..……………………..………………………………… 128 128 מסגרת קונספטואלית...... ………………………………………………..……… 129 129 הערכה מקדמית...... …………………………………………………………… 130 130 שאלות מסגרת...... ……………………………………………..………… 131 131 קשיים פוטנציאליים בהבנת תוצאות של שחזור אקולוגי...…..……….…………….………… 131 131 הצורך בתכנון אסטרטגי בשחזור אקולוגי…………………………………………………… 131 131 נספח II רשימת: מיני זוחלים ודוחיים בחולות ניצנים וסביבתם……………………… ...……….. ……………… 133 133

Boaz Shacham – PhD dissertation ג 142

הקדשה

ברצוני להקדיש עבודה זו לזכרו של אבי יורם (שחם ויינראוב ,ל"ז) אותו לא זכיתי כלל להכיר אך, אך, להכיר כלל זכיתי לא אותו ,ל"ז) ויינראוב (שחם יורם אבי של לזכרו זו עבודה להקדיש ברצוני במרוצת השנים מתברר שהמשיכה למדע והאהבה לטבע קושרות בינינו הרבה מעבר לקשר התורשתי. התורשתי לקשר מעבר הרבה בינינו קושרות לטבע והאהבה למדע שהמשיכה מתברר השנים במרוצת וכמו כן לסביי וסבותיי האהובים לנה, ומשה ביגלאיזן ל"ז ודוניה והייני ויינראוב ל"ז ולמויה, שלגי שלגי ולמויה, ל"ז ויינראוב והייני ודוניה ל"ז ביגלאיזן ומשה לנה, האהובים וסבותיי לסביי כן וכמו ל"ז שלא, זכו בחייהם לפיסת הנחת הממשמשת וקרבה – הילד עומד לקבל תואר .דוקטור .דוקטור תואר לקבל עומד הילד – וקרבה הממשמשת הנחת לפיסת בחייהם זכו שלא, ל"ז

Boaz Shacham – PhD dissertation ב143

תודות

קצרה היריעה מלהכיל את שמות כל אלו להם אני חב תודות על התמיכה העצה, והסיוע שהביאוני שהביאוני והסיוע העצה, התמיכה על תודות חב אני להם אלו כל שמות את מלהכיל היריעה קצרה הלום . . הלום תודה רבה לגופים השותפים במחקר בחולות ניצנים מי, בתכנון מי, במימון ומי בביצוע העבודה העבודה בביצוע ומי במימון מי, בתכנון מי, ניצנים בחולות במחקר השותפים לגופים רבה תודה בשטח תודה. לאנשי אוניברסיטת גוריון-בן בנגב קהמהמחל, למדעי החיים ומהמחלקה לגיאוגרפיה לגיאוגרפיה ומהמחלקה החיים למדעי קהמהמחל, בנגב גוריון-בן אוניברסיטת לאנשי תודה. ב שטח ולפיתוח סביבתי על, ההכנות והתכנון, הלוגיסטיקה והביצוע על, המלגות שאפשרו לי להתרכז יותר יותר להתרכז לי שאפשרו המלגות על, והביצוע הלוגיסטיקה טוב במחקר לאנשי. הקרן הקיימת לישראל שהלכו, עימנו כברת דרך וביצעו בפועל את פעולות פעולות את בפועל וביצעו דרך כברת עימנו שהלכו, לישראל הקיימת הקרן לאנשי. במחקר טוב הממשק הראשונות בשמורה לאנשי. רשות הטבע והגנים הפקחים, אנשי, חטיבת המדע ובנות יחידת יחידת ובנות המדע חטיבת אנשי, הפקחים, והגנים הטבע רשות לאנשי. בשמורה הראשונות הממשק ההיתרים ועל, הסיוע במימון עבודת השדה לאנשי. בית ספר שדה שקמים באתר ניצנים שהוא, לי בית בית לי שהוא, ניצנים באתר שקמים שדה ספר בית לאנשי. השדה עבודת במימון הסיוע ועל, ההיתרים שני ותמיד קרוב לליבי ואשר, משמש אכסניה לכל אנשי הפרויקט בעת הגיחות לעבודת השדה לקרן. לקרן. השדה לעבודת הגיחות בעת הפרויקט אנשי לכל אכסניה משמש ואשר, לליבי קרוב ותמיד שני International Arid Land Consortium) IALC ) אשר, היו פיםשות במימון בשנים הראשונות הראשונות בשנים במימון פיםשות היו אשר, ) לפרויקט למשרד. המדע על ההשתתפות במימון .הפרויקט .הפרויקט במימון ההשתתפות על המדע למשרד. לפרוי קט תודה רבה לאנשים הנפלאים שזכיתי לעבוד עימם וללמוד מהם תוך כדי כך בראש. ובראשונה למנחה למנחה ובראשונה בראש. כך כדי תוך מהם וללמוד עימם לעבוד שזכיתי הנפלאים לאנשים רבה תודה שלי ר"ד עמוס בוסקילה אותו, אני מכיר ומוקיר למעלה מחצי יובל (שנים אם כי שנינו מנסים מנסים שנינו כי אם (שנים יובל מחצי למעלה ומוקיר מכיר אני אותו, בוסקילה עמוס ר"ד שלי להתכחש לזמן לףשח והוא) מורה את דרכי תרתי משמע לפרופ. פועה' בר ר"וד אלי גרונר ללא, ספק ספק ללא, גרונר אלי ר"וד בר פועה' לפרופ. משמע תרתי דרכי את מורה והוא) לףשח לזמן לה תכחש הפלפל והמלח של המשלחת שלנו בניצנים לעמיתי. החוקרים מסטרנטים, ודוקטוראנטים בפרויקט בפרויקט בעבר ובהווה עדי: רמות קונסטנטין, גרץ מרב', פרי אחיקם, אברבוך שרון, רנן טרין, פז יהונתן, יהונתן, פז טרין, רנן שרון, אברבוך אחיקם, פרי מרב', גרץ קונסטנטין, רמות עדי: ובהווה בעבר רובינשטיין כנאילט. השדה המדהימים שלנו ארנון: צעירי יעל, בוגין זילכה- לתלמידי. פרויקט בוגר בוגר פרויקט לתלמידי. זילכה- בוגין יעל, צעירי ארנון: שלנו המדהימים השדה כנאילט. רובינשטיין שהשאירו חותם לא רק בחול אלא גם בלב ארנון: יוחנן שלומי, אהרון נעה, ל'אנג אייל, בן דוד נעמה, נעמה, דוד בן אייל, ל'אנג נעה, אהרון שלומי, יוחנן ארנון: בלב גם אלא בחול רק לא חותם שהשאירו ברנר אירית, מסיקה הדס, אסט אילנה, בן דוד "לאנשי. מילואים שלנו" אשר, תגברו או ריכזו צוותי צוותי ריכזו או תגברו אשר, שלנו" מילואים "לאנשי. דוד בן אילנה, אסט הדס, מסיקה אירית, ברנר בודתע זוחלים בהתנדבות אמיר: ארנון כרמית, ארבל תמר, עמית איתי, רנן גל, וין ערן, בנקר לאבישי. לאבישי. בנקר ערן, וין גל, רנן איתי, עמית תמר, ארבל כרמית, ארנון אמיר: בהתנדבות זוחלים בודתע שלמה ר"וד עודד כהן שותפים, לחיידק ההדרכה בחולות וחברים אמיתיים לעשרות. רבות של של רבות לעשרות. אמיתיים וחברים בחולות ההדרכה לחיידק שותפים, כהן עודד ר"וד שלמה סטודנטים שהיו שותפים לעבודת השדה במסגרת מחנות אקולוגיים של, המחלקה למדעי החיים של, של, החיים למדעי המחלקה של, אקולוגיים מחנות במסגרת השדה לעבודת שותפים שהיו סטודנטים לקההמח לגיאוגרפיה ופיתוח סביבתי ושל מכון ערבה ללימודי הסביבה לעמיתי. תלמידי המחלקה על, על, המחלקה תלמידי לעמיתי. הסביבה ללימודי ערבה מכון ושל סביבתי ופיתוח לגיאוגרפיה לקההמח אינספור שיחות מסדרון מפרות הכנות, והעברת תרגילי מעבדה וסיורים כעוזרי הוראה ופרגון כללי גם גם כללי ופרגון הוראה כעוזרי וסיורים מעבדה תרגילי והעברת הכנות, מפרות מסדרון שיחות אינספור כשחרגתי מהזמן המוקצב בסמינר תלמידי מחקר לצוות. המזכירות המדהים של המחלקה למדעי למדעי המחלקה של המדהים המזכירות לצוות. מחקר תלמידי בסמינר המוקצב מהזמן כשחרגתי יםהחי תמיד, מסייעות ומחייכות אפילו, דרך הדואל חנה: חטב איריס, ראובן דלית, דהן וענת בן בן וענת דהן דלית, ראובן איריס, חטב חנה: הדואל דרך אפילו, ומחייכות מסייעות תמיד, יםהחי הרוש ברשות. הטבע והגנים ר"לד, יריב מליחי ר"ד, יהושע שקדי רונן, שביט קובי, סופר שי, כהן, כהן שי, סופר קובי, שביט רונן, שקדי יהושע ר"ד, מליחי יריב ר"לד, והגנים הטבע ברשות. הרוש איתמר ווליס ליאיר. ון'פרג האיש, והאגדה אשר, ליבה ותידלק את חיידק החולות שלי במקום ותלנס ותלנס במקום שלי החולות חיידק את ותידלק ליבה אשר, והאגדה האיש, ון'פרג ליאיר. ווליס איתמר לרפא אותי וטוב, שכך לאלימור. פריד על, המשך שיתוף הפעולה של ס"בי שדה שקמים עם הפרויקט. הפרויקט עם שקמים שדה ס"בי של הפעולה שיתוף המשך על, פריד לאלימור. שכך וטוב, אותי לרפא תודה למנחה עבודת המוסמך שלי פרופ, יהודה' ל ורנר. על, הכלים (שהקנה וממשיך להקנות לי) לי) להקנות וממשיך (שהקנה הכלים על, ורנר. ל יהודה' פרופ, שלי המוסמך עבודת למנחה תודה כחוקר צעיר . . צעיר כחוקר ותודה רבה אחרונה, וחביבה מאד למשפחתי, היקרה אשר ממשיכה לקבל אותי ואת לכ החיות החיות לכ ואת אותי לקבל ממשיכה אשר היקרה למשפחתי, מאד וחביבה אחרונה, רבה ותודה האחרות הנכרכות אחרי לאמי. נורית שחינכה אותי מינקות לאהבת טבע ובעלי חיים לאחיי, לי אור אור לי לאחיי, חיים ובעלי טבע לאהבת מינקות אותי שחינכה נורית לאמי. אחרי הנכרכות האחרו ת ואורי שמקבלים אותי למרות שאינני מתעניין בכדורגל לאהובתי, שרון שמסכימה לסבול את שעות שעות את לסבול שמסכימה שרון לאהובתי, בכדורגל מתעניין שאינני למרות אותי שמקבלים ואורי העבודה המשונות ואת הדיונות הנודדות לתוך הבית וגם, לתמר בתנו המקסימה שבזכותה כל בוקר בוקר כל שבזכותה המקסימה בתנו לתמר וגם, הבית לתוך הנודדות הדיונות ואת המשונות העבודה נפתח עם סיבה לחייך כולם. כולל, תמר הקטנה שותפים, לפרקים מסעות"ב הציד שלי" .לשמחתי, .לשמחתי, שלי" הציד מסעות"ב לפרקים שותפים, הקטנה תמר כולל, כולם. לחייך סיבה עם נפתח

Boaz Shacham – PhD dissertation א144

העבודה נעשתה בהדרכת בהדרכת נעשתה העבודה

ר"ד עמוס בוסקילה בוסקילה עמוס ר"ד

במחלקה למדעי החיים החיים למדעי במחלקה

בפקולטה למדעי הטבע הטבע למדעי בפקולטה

אוניברסיטת גוריון-בן בנגב בנגב גוריון-בן אוניברסיטת

145 Boaz Shacham – PhD dissertation

ניהול וממשק של דיונות וזוחלים השלכות: לגבי שחזור בתי גידול ואסטרטגיות שימור

מחקר לשם מילוי חלקי של הדרישות לקבלת "תואר דוקטור "לפילוסופיה "לפילוסופיה דוקטור "תואר לקבלת הדרישות של חלקי מילוי לשם מחקר

מאת מאת

בעז שחם שחם בעז

הוגש לסינאט אוניברסיטת בן גוריון בנגב בנגב גוריון בן אוניברסיטת לסינאט הוגש

אישור המנחה ______29 בדצמבר 2010

אישור דיקן בית הספר ללימודי מחקר מתקדמים ש"ע רייטמןק ______

שבט ע"תש ינואר 2010

באר שבע שבע באר

146 Boaz Shacham – PhD dissertation

ניהול וממשק של דיונות וזוחלי: השלכות לגבי שחזור בתי גידול ואסטרטגיות שימור.

מחקר לש מילוי חלקי של הדרישות לקבלת תואר "דוקטור לפילוסופיה " "

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בעז חש חש בעז

הוגש לסינאט אוניברסיטת ב גוריו בנגב

ע"שבט תש 2010ינואר 2010ינואר

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