Author's personal copy Landscape Ecol https://doi.org/10.1007/s10980-020-01091-9 (0123456789().,-volV)(0123456789().,-volV) RESEARCH ARTICLE Scale-dependent correlates of reptile communities in natural patches within a fragmented agroecosystem Guy Rotem . Itamar Giladi . Amos Bouskila . Yaron Ziv Received: 4 May 2020 / Accepted: 5 August 2020 Ó Springer Nature B.V. 2020 Abstract measures are affected differentially by variables Context Studying biodiversity in light of increased related to different scales. fragmentation in agroecosystems requires the under- Methods We sampled reptiles in three 12.6 km2 - standing of scale-dependent and multi-scale determi- land units by using 100 9 50 m plots within 27 nants of various community measures. natural habitat patches. We collected spatial informa- Objectives In a heterogeneous agro-landscape, we tion of different scale-oriented physical and biotic aimed to understand whether: (1) Reptile communities variables and analyzed changes in community mea- are affected by a certain variable that belongs to a sures at four scales—landscape, land unit, patch and particular scale, or, by a combination of variables at plot—by using the model selection approach based on different scales, and (2) Reptile community the AICc. Results Multiple-scale, rather than single-scale models, best explained all three community measures, Electronic supplementary material The online version of this article (https://doi.org/10.1007/s10980-020-01091-9) con- indicating that the reptile community structure is tains supplementary material, which is available to authorized highly affected by ecological processes operating at users. different scales, from the local up to the entire G. Rotem (&) Y. Ziv landscape scale. However, abundance, species rich- Spatial EcologyÁ Laboratory, Department of Life Sciences, ness and diversity were affected dissimilarly by Ben-Gurion University of the Negev, P.O.B. 653, different combined determinants and at different 84105 Beer-Sheva, Israel scales. e-mail: [email protected] Conclusions Reptile biodiversity at our heteroge- Y. Ziv nous agro-landscape is highly influenced by determi- e-mail: [email protected] nants of multiple scales, where each scale has its I. Giladi contribution to the overall obtained pattern. Number of Mitrani Department of Desert Ecology, Jacob Blaustein individuals and species richness respond differently to Institutes for Desert Research, Ben-Gurion University of various processes, depending on the scale at which the Negev, Beer-Sheva, Israel e-mail: [email protected] these processes operate. Agro-landscapes retain the complexity of ecological systems and can serve to A. Bouskila maintain natural communities through land sharing Behavioral Ecology Laboratory, Department of Life practices. Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel e-mail: [email protected] 123 Author's personal copy Landscape Ecol Keywords Abundance Agro-ecosystem AICc 2012). A multi-scale approach to explore biodiversity Á Á Á Community structure Model selection Reptile patterns in natural habitat patches embedded in a Á Á Á Species diversity Species richness relatively hostile environment has been advocated for Á agroecosystems (see Benton et al. 2003; Fahrig et al. 2011). Intensified agricultural practices typically leave natural patches in agroecosystems that vary in size, Introduction isolation, and at risk of biodiversity loss (Yaacobi et al. 2007a; Hogg and Daane 2010). Fundamental ecological theories, such as island bio- A comprehensive understanding of the structure geography (MacArthur and Wilson 1967) and and diversity patterns of a community requires the metapopulation dynamics (Levins 1969), postulate a simultaneous assessment of measures (e.g., total positive relationship between biodiversity in ecolog- abundance, species richness and diversity), reflecting ical patches (i.e., islands or remaining natural habitats) different aspects of the response of the community to and the connectivity between these patches. Ecolog- environmental conditions and to ecological con- ical theories also suggest, either explicitly (e.g., niche straints, such as habitat heterogeneity and climatic theory; Hutchinson 1959; Vandermeer 1972) or effects (Michael et al. 2008). For example, total implicitly (e.g., island biogeography and metapopula- abundance may reflect the biomass and food avail- tion dynamics theories), that greater environmental ability for all individuals, regardless of species identity heterogeneity supports greater biodiversity (Stein (Shine and Madsen 1997; Smart et al. 2000); species et al. 2014). Habitat fragmentation, which character- richness (i.e., the raw and/or corrected number of izes most modern agricultural landscapes, increases species per area unit) may reflect the means by which natural patch isolation and decreases environmental different organisms utilize resources within the com- heterogeneity (Robinson and Sutherland 2002; Green munity (i.e., their niche; Rocha et al. 2008; Soininen et al. 2005; FAO 2007). The latter represent major key et al. 2011); species diversity may reflect the propor- factors that contribute to the loss of biodiversity tional use and subdivision of resources among the worldwide (Sodhi and Ehrlich 2010). The conserva- existing species, thereby providing additional infor- tion of biodiversity in anthropogenic landscapes— mation about realized niches and interactions among such as modern agricultural landscapes—necessitates sets of species (Hiltunen et al. 2006). Importantly, a thorough understanding of such landscapes and because determinants of community structure and ecological processes therein. composition vary with scale (Dumbrell et al. 2008), Contemporary ecology considers species diversity each of these community-related measures may and community structure in natural patches to be a exhibit scale-dependency in a different manner. Con- product of various ecological processes operating at sequently, an advanced understanding of community different scales (Wiens 1989; Yaron 1998; Turner structure in a heterogeneous landscape, such as an et al. 2001; Farina 2006; Hastings et al. 2011). Hence, agroecosystem, may highly benefit from testing the a comprehensive understanding of the processes that effects of environmental determinants on several govern the diversity and composition of species community-related measures using the multi-scale requires a multi-scale approach. Although such an approach. approach has recently become more widespread in In the current study, we applied the multi-scale ecological literature (e.g., McGarigal et al. 2016; approach to study the patterns of reptile assemblage Franciele et al. 2018), it is less common in reptiles (hereafter community) in the semi-arid fragmented studies (but see: Bonnet et al. 2002; Fischer et al. 2004; agroecosystem of the southern Judea lowlands in Michael et al. 2008, 2017; Bruton et al. 2015, 2016). Israel. This study system is located along a very sharp This lacuna is troublesome because reptiles have an climatic gradient and comprises a highly fragmented important role in food-web structure and biodiversity, landscape in which habitat patches of different sizes and because reptiles are known to be highly affected are isolated, partly or entirely, by agricultural fields. by both internal habitat characteristics and landscape Based on our previous studies (Yaacobi et al. 2007a, b; metrics related to isolation, dispersal, and long-term Giladi et al. 2011, 2014; May et al. 2012, 2013; Rotem survival (Brown et al. 2011; Cabrera and Reynoso et al. 2013, 2015; Rotem and Ziv 2016), four explicit 123 Author's personal copy Landscape Ecol scales—landscape (the entire extent with its climatic Methods variation that composes a mixture of reptile commu- nities at different land units), land unit (a cluster of Study area patches that provide opportunities for dispersal and species turnovers for diverse reptile species), patch (an The study area was located in the southern Judean isolated natural habitat that comprises several habitats lowlands (SJL), Israel (31° 240 0000–31° 400 5000 N, 34° and heterogenous local-scale conditions for reptile 480 30–34° 500 300 E; Fig. 1), which represents a species) and plot (a sampling area within a given patch transition zone between desert and Mediterranean which may include few home ranges of particular ecosystems, with precipitation sharply increasing reptiles)—can be identified in this system given its from south to north. The SJL is a meeting area of heterogeneity and complexity, making it an ideal three phytogeographic zones—Mediterranean, Irano- study area for exploring the community structure of Turanian, and Saharo-Arabic—and provides a mixture organisms in a patchy agroecosystem. Specifically, we of plant associations and animal communities of asked: (1) Are reptile communities within our agroe- different biogeographical regions (Zohary 1962). It cosystem affected by a certain dominant variable that is characterized by short mild winters and long, dry belongs to a particular scale, or, alternatively, by a and hot summers, with an average annual precipitation combination of variables that operate at different ranging from 291 mm in the south to 430 mm in the scales? and (2) Are particular measures of the reptile north, over a distance of nearly 20 km. This increase in community structure—abundance, species richness, precipitation from south to north results in a substan- and species diversity—affected differentially by vari- tial