Effects of herbivores and fire on riparian and upland savanna ecosystems

Field Operations Manual for Herbivore & Fire Exclosures on the and Letaba Rivers in the

Compiled by

Thomas O’Keefe and Glynn Alard

December 2002 1

Contents

Project Summary 3

Introduction 5

Project Background and History of Development 5

Guiding Research Questions 7 Vegetation Community and Disturbance Processes 7 Soil Ecology and Biogeochemistry 9 Additional areas of research interest 11

Exclosure Layout 12

Vegetation Sampling Protocol 13 Transects 13 Plots 14 Methods 16 Woody species 16 Herbaceous species 17 Alien 19

Instrumentation Protocol 19 Atmospheric Monitoring 19 Soil Monitoring 20 Ground water Monitoring 21

Fixed Point Photos 21 Fine scale 21 Coarse scale 21 2

Detailed Site Map Methodology 22 Aerial Photography 22

Management 23 Site Management 23 Patrolling & Maintenance 23 Data Management 24 Access 24 Rules and Safety 25 Contacts 27 References 27

Appendix

Kruger Park Map Kruger Park 2000 Flood photos Sabie and Letaba River photos Schematic of Exclosure Layout Fencing Specifications Letaba Site, species list Sabie Site, species list Aerial view of Sabie sites showing basic vegetation associations Field Equipment List Elephant and Fire Impact assessment Aerial photo of Sabie pre and post flood Aerial photo of Letaba pre and post flood Channel detail of Sabie pre and post flood Sabie River site map Letaba River site map Data Sheets 3

Project Summary

Recent (February 2000) floods on the eastern seaboard of Southern Africa inundated large areas of the coastal plain. Rivers draining Kruger National Park (KNP) in experienced flows (c. 8,000 m3 s-1 for the Sabie River) with return intervals of approximately 1:50 years, causing widespread removal of riverine vegetation and extensive alterations to channel habitat. The floods caused widespread human suffering but also provided a unique research opportunity. For the first time in nearly a century we will be able to characterize the long-term development and recovery of riverine forests from a major disturbance.

Savanna landscapes in South Africa are important reservoirs of biodiversity that are affected by expanding human populations and shifting patterns of land use. Within these landscapes, the riverine forests are important boundaries between aquatic and terrestrial systems that define the biodiversity and heterogeneity of these ecosystems.

South African National Parks rates research along with ecosystem conservation as two of its core activities. Together with an international team of scientists we have constructed large exclosures to study the role of herbivory and fire in the alteration and determination of spatial and temporal heterogeneity patterns of vegetation. This research will directly benefit our ecosystem conservation planning.

In their basic form, exclosures are fenced areas designed to keep out animals. At each locality, a pair of exclosures will limit the accessibility of herbivores; one being a “total” (electrified) exclosure, i.e. to exclude all herbivores (-eaters) from a hare upwards in size, and a “semi-exclosure”, consisting only of two cables and electric wiring at 1.8 m and 2.2 m above ground. The purpose of the semi-exclosure is to exclude elephant, and, by virtue of their size, giraffe, but will allow access to all other herbivores. Each exclosure will be divided in half, with one half allowed to burn should fire pass through, and the other kept unburned. These exclosures will extend from within the river channel to the crest, in order to enclose the full sequence of terrain morphological 4

features and their associated soils, vegetation, and smaller fauna. This will allow for the study of the relationships of habitats along the topographic gradient, from the crest to within the river channel. Funding for construction of the exclosures was provided by a grant from the U.S. National Science Foundation and funding from the Kruger Park Marathon Club. Kruger Park staff will maintain the exclosures while continuing to promote involvement with international scientists to conduct research at the sites.

The placement of large herbivore exclosures in the Kruger National Park (KNP) is a fundamental research activity that provides solid evidence on which our whole management policy rests. A critical component of the current research initiative in the KNP concerns the effects of herbivores (especially elephant) and fire on the vegetation and biodiversity of the Park, with the ultimate objective of devising (or revising existing) scientifically based management policies. The rationale behind exclosures is that by excluding these two important modifiers of the ecosystem, their effects on the ecosystem can be determined over time. The proposed exclosures are thus designed to address these issues, as well as post-flood recovery of riparian vegetation which is thought to be heavily influenced by herbivory. As the nature of some ecological changes or processes are of a long-term nature, the exclosures will serve as long-term monitoring and research sites for at least 25 years. At that time, the objectives for the future use of the exclosures should be reviewed. These exclosures will thus provide extremely valuable long-term information on key ecological processes; information that would be nearly impossible to obtain.

The exclosures along the Sabie are located across the river from Nkuhlu picnic site, in the area between the Sabie River and the Salitjie road. The Letaba exclosures are located approximately midway between the low-water bridge over the Letaba, and Mingerhout dam, and thus far from public view in a wilderness area. Special permission was obtained to locate the exclosure here and it may be subject to special research conditions.

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Introduction

Savanna landscapes in South Africa are important reservoirs of biodiversity, and are affected by expanding human populations and shifting patterns of land use. In order to understand and manage these landscapes, several concepts must be employed. Foremost is the application of a modern systems viewpoint (e.g., Likens 1992), which hypothesizes that spatial and temporal heterogeneity of savannas are key to their function (Rogers 1997). In these landscapes, large herbivores and fire are recognized to play an important role in determining these heterogeneous spatial and temporal patterns through their effects on vegetation and the physical landscape. Despite this general knowledge that herbivory and fire are important, careful long-term studies that rigorously document the changes in isolation and as interactions have yet to be conducted.

Through the construction of large herbivore exclosures overlapping with fire treatments our primary research objective is to determine how herbivory and fire alter spatial and temporal heterogeneity patterns. These exclosures will extend from within the river channel to the crest, and encompass the riparian corridor representing a full sequence of geomorphological features and their associated soils, vegetation, and smaller fauna. Riparian corridors are perhaps the most obvious expression of boundaries in savanna regions, and these boundaries defining the heterogeneity of these ecosystems are of particular ecological interest.

Project Background and History of Development

This cooperative program builds on the extensive knowledge base generated by the many decades of research conducted by the Kruger National Park Scientific Services, and the decade-long Kruger National Park River Research Program and more recent River Savanna Boundaries Program in collaboration with several South African and American universities, government departments, and research agencies. The Kruger Park has a long history of interest in the possibility of erection of formal research exclosures (rather than the “incidental exclosures” which have become available because of for instance, enclosures being built to breed up rare antelope). This interest relates 6

particularly relating to fire and elephant effects. Fortunately this historical interest, and the more recent interest of other groups in riparian and riparian-upland issues in the Kruger Park, has provided an opportunity for unified structures dealing with all these interests, to be put in place.

In February 2000 the Kruger National Park was presented with a unique opportunity to develop a long-term experiment designed to examine the effects of herbivory. The largest flood since 1925 for the Sabie (7,000 to 8,000 m3 s-1) and Letaba rivers removed most of the vegetation along these rivers, primary research sites in the park, resetting the system to bedrock and sand. The vegetation before the flood was a mature riparian forest including stately fig and other majestic riparian . The Sabie River catchment is 7,086 km2 with a river length of 230 km and a mean discharge of 633 million m3/a. The Letaba catchment is 13400 km2 with a length of 490 km and a mean discharge of 631 million m3/a. Construction of large exclosures subsequent to this major flood event will allow us to follow the successional development and pattern formation of vegetation along riparian zones. Riparian zones are recognized as “hotspots” of activity because they integrate terrestrial and aquatic systems (Naiman and Décamps 1997). We believe the research we are conducting (viewed across aquatic, riparian and upland zones) will generate a novel understanding of savannas as integrated yet heterogeneous ecological systems. The systems approach to ecosystem study requires ecologists to expose the connections and fluxes between the elements of heterogeneity, and the feedbacks between heterogeneity and ecosystem function (Risser 1995). Therefore, boundaries in the landscape that define this heterogeneity are of particular ecological interest, and riparian corridors are perhaps the most obvious expression of boundaries in savanna regions. The emerging view of system heterogeneity emphasizes that biological richness has many facets (Noss and Cooperrider 1994). The first facet highlights the kinds of ecological systems that are present in a region. The second facet indicates the relative abundance of each kind of entity present in the area. The third facet indicates that the 7

various ecological components are dynamic in time, and that they are functionally connected with one another. Finally, the three facets of kind, relative abundance, and function are expressed in all ecological realms. Therefore, genes, species and populations, communities and ecosystems, and landscapes all can be considered as components of system heterogeneity (Kolasa and Pickett 1991, Collins and Benning 1996). Riparian systems, and their connection to in-stream processes and to interchanges with the upland components of savanna landscapes, provide a powerful test of the functional significance of spatial and temporal ecosystem heterogeneity. The development of this understanding is the overarching mission of our scientific programme.

Guiding Research Objectives

Vegetation Community and Disturbance Processes Under our overall objective of examining the role that herbivory and fire play in the alteration and determination of spatial and temporal heterogeneity patterns, we have identified the following primary research questions:

How does herbivory change the vegetation pattern? When herbivory is imposed on the basic geomorphic template, greater spatial heterogeneity in vegetation may occur resulting in a more structurally and biologically complex habitat. Released from pressure by herbivores, we expect that large trees will display higher growth rates although it will likely take up to 25 years to see this effect.

How does fire affect the vegetation pattern? Although previous long-term studies have been conducted in the park to examine the role of fire in structuring vegetation patterns, we will add focus on the riparian zone and the interaction effects with herbivory.

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How do herbivory and fire affect the regeneration of vegetation following a major flood event? Floods such as those experienced during February 2000 are a rare and major disturbance. We predict that recovery of vegetation will be more rapid in the absence of herbivores, but with less diversity and habitat complexity.

How do herbivory and fires affect seed dispersal, seed germination, and then seedling survival? Because herbivores are important transport vectors for seeds, we expect that in the absence of herbivores, seed dispersal and germination decline. In the absence of fire, we expect seed germination declines as disturbance by fire is recognized to be important for successful germination. Our plots will allow us to examine the interaction between this two factors affecting germination. Finally, we expect that once they are established, fire and herbivory will both decrease individual seedling survival rates.

What effect do animals have on the physical and biogeochemical features of the landscape? One important example of this are pans which are a ubiquitous feature on the landscape. We expect that animal activity is necessary for their continued maintenance. Without animals to keep them open, we predict vegetation will invade and they will close up. In the interim small semi-aquatic fauna may benefit from conditions were there is no major large animal disturbance. Animals likely have an effect on soil structure and erosion rates through physical disturbance of soils and we will be able to examine this.

Our basic methodology to address these research questions will be to characterize riparian and upland vegetation in the different herbivory and fire treatments by measuring basal area, stem density, and canopy dimensions for all woody and herbaceous species at our sites, and individual growth rates of key species of interest that include , Acacia nigrecens, mespiliformis, Kigelia africana, Breonadia salicina, and Trichilia emetica. We will also use fixed-point photography from the ground and aerial photography to document overall changes through time. In addition we will conduct biogeochemistry analyses to characterize the sites themselves and to better understand the features of the physical template that affect the vegetation community. 9

Soil ecology and Biogeochemistry In conjunction with studies on the vegetation community we will also conduct studies on soil ecology and biogeochemistry. These will include long-term experiments of water and nutrient availability on the development of vegetation and soil. The observation of soil water and nutrient status and fluxes will be used to address a number of hypotheses.

Within treatments “The different vegetation types along each transect from crest to river are influenced by the retention capacity and flux of water and nutrients within the soil profiles prevalent at each vegetation type.”

This involves comparison of soil water and nutrient uptake within each transect. Hence soil water monitoring and sampling sites on each transect are located in the riparian zone (2-3 sites), in a sodic zone where these exist and in the upland zone. Here, surface and subsurface water and nutrient fluxes will be studied.

Across treatments “The rate of recovery of vegetation with and without herbivory will depend on the availability of soil water and nutrients.”

Observation of soil water and nutrient fluxes in profiles of similar vegetation types under different treatments will enable factors affecting growth and survival of vegetation to be distinguished between herbivore effects and effects due to water and nutrient availability. Observations will include surface and subsurface water and nutrient balance determination at each site in each treatment.

Transect dynamics “Surface and subsurface fluxes and accumulation both vertically and laterally influence the availability of water and nutrients in specific topographic locations in the transect.”

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Surface runoff and subsurface water and nutrients observations will be used to define the hydrological processes, which result in accumulations of water and nutrients at specific locations in the profile and thereby influence the spatial distribution of vegetation recovery.

Instrumentation that would otherwise be disturbed by large animals will include freestanding equipment to measure atmospheric parameters to provide rainfall input and estimates of potential evapotranspiration boundary conditions. Parameters to be measured at the meteorological stations will include break-point rainfall, air temperature, air humidity, wind speed and direction and solar radiation. Soil water monitoring will include volumetric water content by Time Domain Reflectometry (TDR) and soil water tension status by tensiometry. Techniques have been developed to house this instrumentation within and outside of exclosures so that comparisons of soil water status can be made. The TDR method used will allow for simultaneous measurement of volumetric water content as well as bulk soil electrical conductivity, giving a continuous indication of nutrient and salinity status. The nutrients and salinity will also be sampled periodically to determine the make up of soil water dissolved solids and N-P ratios. The samples will be extracted, either by suction cup lysimeter or by a modified wick method. The exclosures will, for the first time, allow experimental studies of nutrient limitation on plant diversity and productivity. Surface runoff quantity and quality will be observed in runoff plots located at the soil monitoring stations.

Fundamental questions remain as to which nutrients are limiting to riparian vegetation (N or P) and in what elemental ratios, how water availability affects growth and survivorship of key riparian species, and what is the course of ‘terrestrialisation’ once water is removed. Instrumentation that would otherwise be disturbed by large animals will include equipment to measure and sample the following parameters: atmospheric monitoring (air temperature and rainfall), soil moisture, soil temperature, lysimeter and surface water collectors to collect soil and runoff solution for nutrient analysis, and groundwater monitoring wells. The exclosures will, for the first time, allow experimental studies of nutrient limitation on plant diversity and productivity. 11

Additional areas of research interest In addition to these primary research questions, we have identified other areas of research interest particularly in the area of biogeochemistry and will encourage collaborative relationships to develop other projects of interest that are compatible with the primary research objectives set out for the exclosures. The objective is that these exclosures will be used primarily for projects of a long-term nature.

The KNP has a well-documented objectives hierarchy (available at http://parks- sa.co.za, go to Kruger park, Scientific services) which includes explicit research interests, and many of these are obviously catered for by these exclosures. However, more detailed fleshing out, or unpacking, of particular objectives still needs to be carried out to further focus such questions.

Opportunities exist to examine the role of exotics in savanna landscapes. While the most pervasive exotics will be removed in accordance with park management activities (see management section of this manual) we predict that many exotic annuals will be displaced over time as the native riparian forest community develops. With changes in habitat structure we also anticipate changes in fauna including birds, rodents, and insects. This can in turn have feedbacks on the vegetation community that could be studied through the use of long-term mini-exclosures for these groups located within the large exclosure.

Additionally, in the next few years KNP will be embarking on a large-scale experiment to actively move elephants into high and low-density areas within the Park. The Sabie River exclosure will be constructed in an area destined to have low elephant densities, whereas the Letaba site is destined to have high elephant densities. Therefore, secondarily the exclosures will be used in cooperation with the large-animal researchers to quantify the long-term effects of differential elephant browsing and fire on ecosystem processes.

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Exclosure Layout

Cost and practical considerations prevented us from replicating exclosures in a manner consistent with traditional statistical techniques. Despite this, large-scale ecosystem experiments have made important contributions to ecology, and this approach was selected for the design of these exclosures. While the scale selected makes replication prohibitive, designing smaller exclosures would have introduced edge effects and prevented us from effectively addressing many of the ecosystem questions that are of primary interest.

The design selected addresses the shortcoming of non-replication by incorporating basic principles that others have successfully used to address ecosystem questions (Carpenter and Kitchell 1993). The manipulations are strong and sustained with exclosures being used to apply a strong treatment effect with regard to herbivory. Statistical techniques designed for large-scale ecosystem experiments have been developed and successfully implemented (Matson and Carpenter 1990) which will be used in conjunction with ecological interpretation of changes that occur.

Exclosures are located at two sites within the Kruger National Park; one along the Sabie River and one along the Letaba River. At each locality, a pair of exclosures were erected; one being a “total” (electrified) exclosure, i.e. to exclude all herbivores (plant- eaters) from a hare upwards in size, and a “semi-exclosure”, consisting only of two cables and electric wiring at 1.8 m and 2.2 m above ground. The purpose of the semi-exclosure is to exclude elephant, and, by virtue of their size, giraffe, but will allow access to all other herbivores.

The exclosures are approximately 50 ha (1.0 x 0.5 km) in size and separated by an unfenced distance of approximately 400 m. They extend along the catena, from within the river channel to the crest, in order to enclose the full sequence of terrain morphological features and their associated soils, vegetation, and smaller fauna. This will 13

allow for the study of the relationships of habitats along the topographic gradient, from the crest to within the river channel. Part of the latter will be included in "sacrificial" exclosures, so-called because they may sustain damage and are designed to be reconstructed when the river floods (bankfull events with a 5-10 year recurrence interval) Nevertheless, they will serve a very important function as it is the lower riparian zone that took the brunt of the impact by the recent floods and underwent the greatest change

In order to introduce fire as an experimental treatment in the areas, each exclosure will be divided approximately in half with a firebreak. All natural fires will be allowed to enter the exclosures from outside, but hopefully, will always be excluded from the no- burn treatments. In addition, the open area between the two exclosures will act as a no burn reference area, and the unfenced reference area at the outside ends of the exclosures will serve as a natural fire regime treatment A total of six treatments will thus be possible. See the diagram in the appendix for details.

The exclosures along the Sabie are located across the river from Nkuhlu picnic site, in the area between the Sabie River and the Salitjie road. The Letaba exclosures are located approximately midway between the low-water bridge over the Letaba, and Mingerhout dam, and thus far from public view. Permanent interpretive signs at Nkuhlu picnic site and along the Salitjie road provide an explanation and general background on the exclosures, for the benefit of park visitors.

Exclosure Vegetation Sampling Protocol

Transects We have established two permanent transects in each of the six treatments. Transects extend from the river to the crest of the catena, perpendicular to the river channel. Transects are as evenly spaced as possible within each area, and at least 100 m from fences and at least 30 m from firebreaks and areas where construction activity was 14

concentrated. The location and bearing of the transects was determined using aerial photographs and 1:50 000 maps.

Permanent markers (25 x 25 x 50 cm concrete benchmarks) are located at the ends of each transect. The transects have been laid out in two steps. In the riparian zone a digital theodolite with a compass was used to establish a straight line from the benchmark along the bearing of the transect. In the uplands, where density increases and a straight, line of sight for the theodolite would be obscured by tree canopies, the line was extended along the same using a differential GPS geo-referenced to a nearby base-station to ensure accuracy.

Along the transect, stakes (12 mm steel reinforcing bar) are placed every 10m in the riparian zone and every 20 m in the upland. These points correspond to the location of permanent vegetation plots located on the downstream side of the transect but will also be used to relocate the transect for other studies. In the riparian zone, these distances were measured using the theodolite and in the uplands where the transect was continued with the GPS, the distances were measured using a laser rangefinder.

Plots Permanent vegetation sampling plots have been established 5 m downstream from the transects (to reduce disturbance on the plots from other uses of the transect lines.) Plots are 10m x 20m, with the long side parallel to the river channel.

Within the riparian zone, the permanent vegetation plots are contiguous to the top of the macrochannel bank. As the upland limit of the riparian zone may be unclear following the flood, a minimum of 6 plots are sampled at the beginning of each transect. This allows for sampling from the edge of the active channel up to the top of the macrochannel bank (where the sodic areas start). Most of the riparian zone will be between the permanent and temporary fences (temporary fences are the ones that we expect may be damaged in flood events, but they will be repaired as soon as possible after such events). The plots in the riparian zone will be contiguous as this area has a high 15

biodiversity and it is a narrow zone. Also, it is in this zone that most vegetation succession will occur due to post-flood community development. Contiguous plots ensure that data of this vital zone is maximized and thus future understanding of the spatial and temporal heterogeneity of the riparian zone is improved.

Plots in the sodic sites (where present) and uplands will be the of same dimensions (10m x 20m) and distance from the transect (5m). These plots will be spaced 20m apart along the transect. Plot placement may be subject to minor adjustment so as to avoid areas of construction activity including roads used by the building crew. The sodic sites and uplands are more extensive and vegetation patterns are more uniform; these areas were not altered to the great extent that the riparian zone was during the floods. Therefore, the scale of temporal heterogeneity will not be as great as in the riparian zone. For these reasons, sampling need not be as intensive.

The river-upstream (UU) corner of each plot will be 5m perpendicular from the transect, and correspond to the 20m stakes along the transect. All 4 corners will be exactly located and permanently marked by hammering 12mm steel re-bar stakes into the ground. Each stake is 0.5 m long, and approximately 10cm will be left exposed. Each stake will be marked with grooves that will indicate their position so that if only corner can be found, it will be possible to re-establish the plot correctly. • 1= Upland-upstream (UU) • 2= River-upstream (RU) • 4= River-downstream (RD) • 3= Upland-downstream (UD) Further, the GPS co-ordinates of the UU corner of each plot will be found using a differential GPS. Finally, a reference photograph will be taken diagonally across the plot from the UU to the RD corner using a 28 mm lens and a monopod at a height of 2 meters.

In order to measure the degree of alluviation and illuviation (riparian zones only), the length of the RU stake extending from the ground will be measured to the nearest mm. 16

Methods

Woody vegetation sampling A brightly coloured 60 m rope will be extended around the stakes to clearly mark the edges of the plot and clarify which individuals fall within and outside the plot. All plants rooted within the plot are recorded, i.e. even if the entire canopy of a tree extends into a plot but it is rooted outside, it will not be recorded, and vice versa.

When it is not clear what constitutes an individual within a clump of multiple stems or when stems may result from vegetative reproduction, clumps which are 0.5m or further apart will be classified as different individuals.

Two canopy heights will be taken for each individual:

1. The height to the top of the tallest branch will be measured using a clinometer if the individual is too tall to measure with a stadia rod. Tall trees that cannot be measured from within the site will be measured from as far back as necessary to see the top of the tree. 2. The height of the lowest foliage (which could be a single twig with leaves) will be measured.

Two canopy diameter measurements perpendicular to each other will be taken for each individual across the longest and shortest perpendicular axes of the canopy.

The diameter of every stem will be measured just above the basal swelling, using callipers for stems <5 cm in diameter and a diameter tape for stems >5cm in diameter. Where an individual consists of more than 10 stems, the number of stems will be counted and recorded; 10 stems will then randomly be measured for diameter. Dead stems will be recorded as such, but will be measured. These records of dead stems are to be written and then circled. Obviously, no foliage exists on a dead tree, therefore only the total height will be recorded.

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Further, elephant damage to the individual will be noted. Qualitative data will be recorded (type of damage e.g. broken side branch, tree pushed over, scar in trunk) and quantitative data will also be recorded (the extent of damage will be described e.g. what percentage of the tree is damaged) following the methods of Anderson & Walker (1974). If the cause of the damage is not known, it will not be speculated upon, as this is often very difficult to determine.

Fire damage will be assessed in order to capture the extent of past fires (e.g. main, primary or secondary stems killed or alive).

Any impact of a known or unknown cause other than elephant and fire will be recorded listing the cause of impact, if known. The following mammals have visible impacts on woody vegetation and will be indicated by the use of the following codes: • Porcupine = P • Giraffe = G • Kudu = K • Buffalo = B • Unknown = X • Other = O

If the impact is not the cause of any of the above, and the cause is known, it will be noted as such in the notes column.

Finally, there will be notes field in the data sheet to record additional discretionary information that may be important.

Herbaceous vegetation sampling The herbaceous biomass of each plot will be estimated by dropping a disc pasture meter every 2 paces across the E to W diagonal of the plot. The disc is not to be dropped onto any woody or other non-herbaceous material, as this would give a false reading. A minimum of 7 readings is required for calculation. The disc pasture meter is calibrated 18 for the conditions and vegetation of the lowveld, and is used to calculate the standing crop or fuel load.

Within each plot, two 1 m2 circular sub-plots will be sampled for herbaceous vegetation. A metal hoop 1.12 m in diameter (1m2 in area) will be placed in the N and then in the S corner. A circle is used as it has the least circumference relative to area, and thus decreases the disputes of “borderline” plants. As with woody plants, only individuals rooted in the circle will be recorded. Two thin metal poles will be laid at right angles at ground level to sub-divide the hoop. This makes sampling much easier as mat forming herbs are difficult to keep track of. Every life form will be counted and recorded, including algal mats (% cover will be estimated), mosses, and ferns. All plants will be identified to the furthest level possible, i.e. species level.

Within each 1m2 circular sub-plots: 1. Every forb will be identified and recorded to determine species abundance and density. When a species occurs in very large numbers, rendering it impractical and inaccurate to count individuals, sub-sampling will be used. A circle of known diameter will be used (e.g. cellotape role). Also, when the total diameter of any forb is less than 1 cm, and many occur in the plot, subsampling will be done by tossing the sub-sample into the ring randomly four times and counting all such minute individuals.

For stoloniferous forbs, each rooted point will be counted as an individual.

2. Every grass species will be identified and recorded.

For grasses that form a tuft base, basal diameter will be measured. For stoloniferous grasses, the diameter of all rooted points will be measured and treated as individuals. This can be used to measure the amount of basal cover.

3. % cover of algal mats will be estimated. 19

Herbarium specimens of all plant species will be collected, preferably not from within the plots, so that these can be compared in future surveys if/when confusion arises regarding species identifications (especially if species have been taxonomically split). Although taking specimens from within the plot destroys seed producers and individuals which may need to be surveyed in the future, this trade-off has been decided upon as the future benefits of a reference collection outweigh the minimal damage that will be done to the site. However, unnatural disturbance (of which specimen collection is an example) must at all times be kept to an absolute minimum within the plots where possible.

Surveying of Alien plants Woody alien plants present at the time of survey will be recorded but not in the same detail as the indigenous species. Total canopy height will be measured and a subjective visual estimate of percentage cover will be made. It would be valuable to monitor the presence of alien populations historically over time subjected to the various treatments. However, alien plant eradication/removal will continue as part of the SANParks/Working for Water management programme.

Instrumentation protocol

Instrumentation is designed to facilitate study of spatial and temporal variation in environmental parameters and nutrient dynamics at critical points along a transitional toposequence from the river edge to the upland boundary. This will provide us with greater insight on the physical template at our sites. We anticipate deploying one meteorological station and twenty-six soil water-monitoring stations at each site (Sabie and Letaba). These will comprise either four or five stations along each of six transects located in each treatment. Sampling stations will be selected to capture local topographic and vegetation variation.

Atmospheric monitoring A simple weather station at each site will measure point rainfall, air temperature, air humidity, wind speed and direction and solar radiation. These data will be logged on a 20

10-minute interval and resolved to yield daily summaries.

Soil monitoring Volumetric soil water contents will be continuously monitored at specific sampling stations using TDR probes installed at various depths in the profile and connected to a data logger. These will provide data that are critical to understanding water and solute movement, both locally and across the toposequence and will be useful in assessing the importance of soil moisture to nutrient transformations. The TDR measurements are sophisticated and expensive, yielding both volumetric soil water contents and soil water electrical conductivity (EC) measurements simultaneously. Two sets of recording instrumentation will be available. These can be moved from station to station to record intervals of soil water and EC measurements where probes have been installed. In addition to the TDR, each station will be equipped with three or four automatic recording tensiometers, positioned at different depths within the profile. The tensiometers will record the soil moisture tension and provide a record of the prevailing direction and gradient of the soil water potential. These data will be used to determine both the water and nutrient balance at each location as well as the mechanisms and rates of vertical and lateral accumulation or uptake.

Soil solution will be collected either in ceramic cup lysimeters or modified wick samplers. Two samplers will be installed at each station: a shallow lysimeter (15 cm depth) for sampling nutrient concentrations in surface soil horizons and a deep lysimeter to sample for changes in solute chemistry as rainwater infiltrates into deeper soil layers.

Gaseous losses are of major interest in determining the fate of nitrogen and carbon. A permanent collar for attachment of a gas collection enclosure will be installed in each sampling station. Permanent installation of collars is necessary to minimize the effects of soil disturbance on gas evasion rates.

Surface runoff is an important vector for loss of nutrients during storms. A sampler for collecting surface runoff during storms will be installed at each sampling 21

station. Runoff collectors will be simple standpipes installed vertically in the soil, with the upper lip slightly above the level of the soil to intercept surface-draining water.

Soil temperature sensors will be installed in six of the sampling stations at different distances along the toposequence

Ground water monitoring Changes in ground water height are important indicators of surface water ground water interactions. Wells for monitoring ground water height and for sampling ground water chemistry will be installed in selected upland sites with deep water tables. At sites where the water table is three meters or less deep and either perched or permanent water tables are anticipated, wells will be installed to a depth of 3m. Water level sensors will be installed in six wells to continuously monitor groundwater height.

Fixed-Point Photography

Fine-scale A final decision has yet to be made on the exact locality of fixed-point sites. The suggestions were made to take one (1) photograph per transect plot along a diagonal line (will still have to decide on the direction) and at a fixed height which necessitates the usage of a tri- or monopod. The problem with this way of taking fixed-point photos is that because only short distances are covered, trees and taller shrubs will not fit entirely onto photographs. An alternative way would be to cover longer distances along the transects, i.e. to take a photograph every 50 m or so while standing on the centre line (middle of transects), thereby including the whole spectrum of height classes of woody plants. Frequency and timing must be consistent, in other words photographs will have to be taken annually during the same time of day of same month.

Coarse-scale In addition to the above-mentioned points, other sites can be selected in order to gain an 22

overall bigger overview of the vegetation across the exclosures. Potential sites include corner points in the fences and or junctions of internal firebreaks with fences. Such sites would be easy to find and also show out differences between burned and unburned blocks. Frequency and timing must be the same as above.

Detailed Site Map Methodology

A once-off detailed (fine-scale) set of aerial photographs will have to be taken during 2003 in order to produce a digital elevation model (DEM) at a spatial resolution of 0.5 m, reflecting three-dimensional differences between vegetation types along the catenas as well as indicating contour lines to illustrate changes in topography. The DEM can be used to assist in compiling detailed maps of the entire exclosures as well as immediate surrounding areas in terms of plant communities, soil types, geology and drainage.

A company will be hired to take the aerial photographs and produce the DEM. The classification of the vegetation, soils and geology can be handed out as research projects to students under good supervision of an academic institution.

Aerial photography

Large and/or small-format aerial photography will have to be conducted on an annual basis approximately the same time of the year. Fine-scale photography at high spatial resolution will be required if even small changes in vegetation cover and drainage lines are to be detected. Changes in the number of large trees, size of sodic patches, bush encroachment and NDVI are amongst the parameters that can be extracted from such photographs. The possibility of Scientific Services conducting the large-format photography will be investigated since the camera belongs to CSIR but is out on loan to Scientific Services. Should it not be possible to pursue this option, the alternative would be to use small- format photography as is currently applied in the rest of the KNP.

23

Management

Site Management An exclosure committee has been formed in order to manage the site in terms of maintenance decisions and scientific studies/surveys. The various members of the committee as well as brief explanations of their respective roles in the exclosure project are:

Dr R. Scholes [CSIR]– external and moderating advice in terms of research, monitoring and data & site management

Dr H. Eckhardt [SANParks]– convener/chairperson of the committee; areas of involvement include inter-departmental matters relating to exclosures [funding, maintenance, strategic planning], conceptual advice, remote sensing.

Mr N. Zambatis [SANParks]– construction overseer and management, matters relating to site management and development, conceptual & vegetation science advice.

Mr Thando Msomi [SANParks]– site management, maintenance, staff management, general matters.

Mr G. Alard [Wits University, RSBP]- baseline vegetation surveys, research-staff management and training, instrumentation monitoring, general matters.

Patrolling and Maintenance The relevant rangers will be in charge of the patrolling and reporting of breakages. The idea is that the patrolling team should have the capacity to fix minor breakages and only report major damages to the maintenance team at . Technical Services in Skukuza will delegate the repair work of major damages to an outsourced contractor.

A wider strip along the fences has been cleared of all vegetation, meaning trimming branches, removing bushes and shrubs, and keeping the herbaceous layer very short in order to improve visibility for animals but also to enable better maintenance and prevent shortages in the electrical system. The herbaceous layer will be maintained in order to prevent erosion. 24

A firebreak has been created in both the full and partial exclosure. Only woody plants were removed, but the herbaceous layer will be maintained although it will be kept short to prevent fire jumping. Scientific Services’ fire ecology department will maintain the firebreak.

Data Management

Objectives: Make data widely available in timely fashion while protecting intellectual property rights of program participants.

Guidelines: Data collected as part of the long-term monitoring efforts will be made available to those participating in projects within the exclosures. After two years these data will be publicly available. Kruger Park Scientific Services will coordinate data management for these data.

Researchers who wish to publish data from the exclosures or associated long-term monitoring efforts must specify an intent to publish with Kruger Park Scientific Services and acknowledge the source of the data.

Researchers who conduct individual projects within the exclosures will serve as custodians for data that they collect, but will be expected to contribute their data to the data manager upon completion of their project. Those collecting more general monitoring data may be asked to contribute on a more regular basis to be established in consultation with the program participants.

Access control of Exclosure sites Even though the exclosure sites are areas which have been impacted upon and manipulated by humans, the areas remain part of the Kruger National Park, and therefore all rules and safety practices required of all National Parks must at all times be upheld. It must be remembered at all times that the sites have been selected for the purpose of 25 research, and that any impacts/unnatural processes within the system will negatively affect the results of the project. The sites are under the management of Conservation Services but access is controlled by Scientific Services. Therefore permission must be sought from Scientific Services to enter the area. Entrance will be limited to officially approved visitors and those participating in a SANParks registered scientific project.

Rules & Safety

For the safety of those entering the exclosure for whatever purpose it is imperative to note the following: • The KNP falls within a “big five” or “dangerous game” area. Those entering the area on foot must at all times be accompanied by a game guard; or will have to carry a firearm (if allowed to). Heavy calibre rifles such as .375 or .458 are recommended. Keep in mind that even though the full exclosure is supposed to be free of large dangerous game, breaks in the fence may occur, allowing access to dangerous game. Buffalo, hippo, rhino, lion and leopard may be found in the partial exclosure. SANParks indemnifies itself of any damage of property, injury or death which may occur in or around the exclosure sites. • A fairly well equipped First Aid Kit must be taken along on all field excursions. Special note must be made before embarking that adequate supplies and knowledge is available to treat accidents such as snake/scorpion bites, broken/sprained bones and joints, etc. • No mobile phone reception is available in the exclosure sites. Communication measures must be taken to avoid unnecessary dilemmas. Make enquiries at scientific services if any two-way hand held radios are available. If not, communicate the excursion schedule with persons in Letaba/Skukuza, should you not return within a certain time frame, appropriate rescue/search procedures may be put into action. • It goes without saying that thorough vehicle and fuel checks must be done before embarking for the exclosure site. • Always make sure that an ample supply of water is available for the excursion. This 26

could be crucial for use with injuries, heat stress, dehydration, vehicles, etc. • The fence is electrified; do not touch it.

General rules apply to all who enter the exclosure sites: • At all times the uppermost intention should be to inflict minimal impact within the sites – remove nothing (unless it is for research purposes) and add nothing (unless it is for research purposes). • Littering is strictly prohibited. Please remove all foreign materials from the site after completion of field work (e.g. cigarette stubs, paper, piping, off-cuts, etc.) • Keep gates closed at all times. The keys are available from Scientific Services. • Drive only on the roads provided. Soils in the sodic sites are particularly sensitive and prone to erosion if heavily impacted, therefore under no circumstances will vehicles be allowed on the sodic sites. • It is KNP policy to prohibit collecting of in the veld. This is even of greater importance within the exclosure sites. Removal of rocks and firewood destroy microhabitats and remove a valuable source of nutrients. • Avoid walking on the vegetation sampling plots; the transect lines 5 m upstream of the plots were created to orientate researchers to the plots to obviate direct walking on them. • Damage or removal of living material is strictly prohibited, except during collection of herbarium specimens • Report any strange occurrences or sightings in exclosure e.g. break in fence, open gates, game sightings in full exclosure, etc. • Do not tamper with the box containing the power source for the fencing. This is primarily for your safety. Please report any visible signs of tampering on the electrical equipment. • Various hydrological and soil monitoring equipment has been installed within the exclosure sites. Do not tamper with this equipment. • Restrict ablutions to areas well away from vegetation survey plots and soil\hydrology monitoring installations.

27

Contacts/Current Projects

Glynn Alard, [email protected], University of the Witwatersrand Dr. Harry Biggs, [email protected], South African National Parks Dr. Holger Eckhardt, [email protected], South African National Parks Angela Gaylard, [email protected], University of the Witwatersrand Dr. Shayne Jacobs, [email protected], University of Washington Judith Kruger, [email protected], South African National Parks Dr. Simon Lorentz, [email protected], University of Natal, Pietermaritzburg Thando Msomi, [email protected] , South African National Parks Prof. Robert Naiman, [email protected], University of Washington Thomas O’Keefe, [email protected], University of Washington Prof. Kevin Rogers, [email protected], University of the Witwatersrand Dr. Robert Scholes, [email protected], CSIR Jacques Venter, [email protected], South African National Parks Nick Zambatis, [email protected], South African National Parks

References:

Anderson. G.D. & Walker, B.H. 1974. Vegetation composition and elephant damage in the Sengwa Research Area, Rhodesia. J. Sth. Afr. Wildl. Mgmt Ass. 4(1): 1-14.

Collins, S.L. and T.L. Benning. 1996. Spatial and temporal patterns in functional diversity. Pages 253-280 in K. J. Gaston, editor. Biodiversity: a biology of numbers and difference. Blackwell, New York.

Kolasa, J., and S. T. A. Pickett, editors. 1991. Ecological heterogeneity. Springer-Verlag, New York.

Likens, G. E. 1992. Excellence in ecology, 3: The ecosystem approach: its use and abuse. 28

Ecology Institute, Oldendorf/Luhe, Germany.

Naiman, R.J., and H. Décamps. 1997. The ecology of interfaces — riparian zones. Annual Review of Ecology and Systematics 28:621-658.

Noss, R. F., and A. Y. Cooperrider. 1994. Saving nature’s legacy: protecting and restoring biodiversity. Island Press, Washington, DC.

Risser, P. G. 1995. Biodiversity and ecosystem function. Conservation Biology 9:742- 746.

Rogers, K. H. 1997. Operationalizing ecology under a new paradigm: an African perspective. Pages 60-77 in S. T. A. Pickett, R. S. Ostfeld, M. Shachak and G. E. Likens, editors. The ecological basis of conservation: heterogeneity, ecosystems, and biodiversity. Chapman and Hall, New York.

Kruger National Park

Effects of herbivores and fire on post-flood recovery of riparian ecosystems

Appendix SOUTH AFRICA BASALT

Letaba Site

GRANITE

Sabie Site

THE KRUGER NATIONAL PARK (KNP)

Almost 2,000,000 ha (4,942,000 acres) in size, the KNP is 350 km (212 mi) long and on average, 65 km (41 mi) wide. It extends from 22˚ 20’ to 25˚ 30’ S. Mean altitude above sea level is approximately 320 m (1,050 ft).

The KNP is situated within a tropical to semi-tropical region, with deciduous savanna vegetation. It is predominantly arid to semi-arid, with summer rainfall, generally from November to March). Mean rainfall is 530 mm (21 in), varying from about 430 mm (17 in) in the Limpopo river valley in the extreme north, to some 800 mm (32 in) on the low mountains in the south-western corner. Summers are hot, with a mean temperature of 26.3°C (79.3°F), with mild winters. Frost is a rarity.

The Sabie and the Letaba rivers flow over the two major geological formations in the park, granite and basalt, resulting in two distinct channel types and vegetative communities. Kruger National Park Floods (February/ March, 2000) Floods on the eastern seaboard of Southern Africa inundated large areas of the Mozambique coastal plain, extending well beyond the alluvial floodplain. Rivers draining Kruger National Park (South Africa), which are tributary to the Limpopo River in Mozambique, experienced flows (c. 8,000 m3/s) with return intervals of approximately 1:150 years, causing widespread removal of riparian vegetation and extensive alterations to channel habitat. The floods caused widespread human suffering but also provided a truly unique research opportunity. For the first time in nearly a century there is the possibility to describe and manipulate the long-term recovery of riverine forests. Sabie River

Letaba River

These photos are taken near the study sites. SCHEMATIC LAYOUT AND TREATMENTS TO BE APPLIED TO THE EXCLOSURE SETS

PARTIAL EXCLOSURE FIRE BREAK FULL EXCLOSURE

BURNED AREAS UNBURNED BURNED AREAS AREAS

F E B C A D F

SACRIFICIAL EXLOSURES

floodplain

river channel

HERBIVORE UTILIZATION FIRE TREATMENT FULL ACCESS ELEPHANTS EXCLUDED ALL EXCLUDED NO BURN A B C BURNED D E F

At each site, a pair of exclosures was erected; one being a “total” (electrified) exclosure, i.e. to exclude all herbivores from a hare upwards in size, and a “semi-exclosure”, consisting only of two cables and electric wiring at 1.8 m and 2.2 m above ground. The purpose of the semi-exclosure is to exclude elephant, and by virtue of their size giraffe, but will allow access to all other herbivores.Transects outside the exclosures will be used to chacterize vegetation recovery in the presence of all herbivores. In addition to herbivore utilization, fire will also be a treatment variable. Plots in the burn areas will be allowed to burn following the natural fire regime of the surrounding landscape (i.e. natural fires). The fire break will prevent these fires from entering the unburned plots.. There will be two transects in each of the six treatment combinations with contiguous 10 x 20 m plots along each transect. Specifications: Fencing: ·Galvanized steel posts (101 x 2.5 mm) and stays (48 x 2.0 mm) concreted at 80 m intervals. ·76 mm intermediate posts at 20 m. ·Y-section standards every 5 m. ·2 droppers between standards. ·Concrete lintel 200 x 100 mm under fence. ·3 strands of 4 mm galvanized wire. ·3 rows of 12 mm black cable and shackles. ·Diamond mesh 1.2 m x 63 x 2.5 mm

All tied with 2.5 mm wire.

Other equipment: · 2 sets of shock equipment per exclosure pair comprising energizers, solar panels, batteries, a shock box to house and protect the equipment. The reason for having two systems per exclosure set is that one powers two wires and the second the remaining three wires. Thus in the event that a wire is broken or shorts, the exclosures are still provided with some protection. · Current-disruption radio transmitter and receiver, effective up to 100 km on flat terrain. · Double-leaf gate with electrification. Plant Species List for Letaba study site. Note, this is an incomplete list based on the 2001 survey that only included half of the transects in the riparian plots. No upland plots were included.

Herbaceous Species Woody Species Ageratum houstonianum Acacia nigrescens Alternanthera pungens Brachylaena discolor Argemone mexicana Cassia abbreviata Argemone ochroleuca Colophospermum Aristida congesta ssp. Congesta Combretum apiculatum Centela asiatica Combretum erythrophyllum Chloris virgata Combretum hereroense Crabbea angustifolia Combretum imberbe Crabbea ovalifoli Combretum microphyllum Cynodon dactylon Combretum spp Cyperus compressus Communis ricinus Cyperus esculentus Croton megalobotrys Cyperus rotundus Dichrostachys cinerea Dactyloctenium aegyptium Diospyros mespiliformes Datura spp. Ehretia rigida Digitaria eriantha Euclea natalensis Echinochloa pyramidalis Ficus sycomorus Eragrostis heteromera Fluggia virosa Eragrostis lehmanniana Jasmine Eragrostis rotifer Lantana camara Helichrysum argyrosphaerum Lonchocarpus capassa Heliotropium steudneri Nuxia oppositifolia Oxalis spp. Pappea capensis Panicum maximum Phyllanthus reticulatus Paspalum scrobiculatum Pyrostria hystrix Phragmites australis Rhoicissus tridentata Pogonarthria squarrosa Senna spp Schmidtia pappophoroides Terminalia pruiniodes Sphaeranthus incisus Trichilia emetica Sporobolus africanus Ximenia caffra Sporobolus ioclados Sporobolus nitens Tagetes minuta Urochloa mosambicensis Urochloa panacoides Verbena bonariensis Verbena brasiliensis Vernonia natalensis Plant Species List for Sabie study site. Note, this is an incomplete list based on the 2001 survey that only included half of the transects in the riparian plots. No upland plots were included. Herbaceous Species Woody Species Ageratum houstonianum Acacia burkei Ageratum spp. Acacia erubescens Alternanthera pungens Acacia grandicornuta Amarathus spp Acacia nigrescens Bothriochloa insculpta Acacia robusta Centela asiatica Acacia spp Chloris gayana Albizia anthelmintica Chloris virgata Albizia harveyi Commelina erecta Berchemia discolor Commelina livingstonii Berchemia spp Commelina spp Bolusanthus spp Crab spp Cassia abbreviata Crabbea angustifolia Combretum apiculatum Crabbea hirsuta Combretum hereroense Crabbea ovalifoli Combretum imberbe Cymbopogon plurinodes Combretum molle Cynodon dactylon Combretum spp Cyperus esculentus Commiphora africana Cyperus rotundus Commiphora neglecta Dactyloctenium aegyptium Commiphora spp Dactyloctenium geminatum Dalbergia melanoxylon Echinochloa pyramidalis Dichrostachys cinerea Eleusine coracana Diospyros mespiliformes Eragrostis rotifer Dovyalis spp Eragrostis superba Ehretia obtusifolia Eragrostis trichophora Ehretia rigida Euphorbia spp Ehretia spp Heliotropium steudneri Euclea divinorum Heteropogon contortus Euclea natalensis Lantana camara Ficus sycomorus Mariscus congestus Fluggia virosa Oxalis corniculata Gardenia spp Oxalis spp Gardenia volkensii Panicum deustum Grewia bicolor Panicum maximum Grewia flavescens Panicum schinzii Grewia hexamita Paspalum distichum Grewia occidentalis Paspalum scrobiculatum Grewia spp Ruellia cf. patula Jasmine Ruellia spp Kigelia africana sedge Lantana camara Solanum panduriforme Lonchocarpus capassa Sorghum bicolor subsp. Arundinaceum Melia azederach - ALIEN Sphaeranthus incisus Pappea capensis Sphaeranthus spp Peltophorum africanum Sporobolus africanus Phyllanthus reticulatus Sporobolus ioclados Phyllanthus spp Sporobolus nitens Pyrostria hystrix Tagetes minuta Rhus queinzii Themeda triandra Sclerocarya birrea subsp. Caffra Tragia rapratis Securinega spp Urochloa mosambicensis Securinega virosa Urochloa panacoides Senna spp??ALIEN?? Verbena bonariensis Spirostachys africana Verbena brasiliensis Strychnos spinosa Wahlenbergia caledonica Syzygium guineese Thilachium africanum Trema orientalis Trichilia emetica Zanthoxylum capense Ziziphus mucronata SEASONAL STREAM CREST

Combretum-Sclerocarya ASSOCIATION

SODIC AREA

RIPARIAN & IN-STREAM COMMUNITIES AND ASSOCIATIONS

Aerial View of site on the Sabie River at Nkuhlu Picnic siteillustrating the major vegetation communities. Surveying Theodolite Rain cover Tripod Poles (4) Reflector Data Sheets Clipboard Stake descriptions Stakes Field Equipment and Supplies required for Vegetation Survey Compass reconcile lists--more detail on equipment specs Map Hammer Pencils (2) and eraser Differential GPS Extra battery (CHARGED) Laser rangefinder Digital theodolite, tripod, reflector, poles Herbaceous 50 cm x 12 mm steel re-bar stakes (pointed end) ring hammer Data sheets flagging disc pasture meter compass small subsample ring camera, 28 mm lens, and monopod ID books ( and grasses) Stake descriptions spray paint Clipboard concrete markers Field herbarium(s) Cello tape 60 m bright nylon rope 1m2 frame 1.12 m cross pieces for metal hoop Woody calipers Compass diameter tape Clinometer measuring tape (100 cm) DBH tape (5m and 10 m) disc pasture meter Calipers 30 m tape measure Stake descriptions stadia rod Data sheets clinometer Pencils (3) and eraser Clipboard plant press Tree Book Field herbarium plant id sheets Tape vegetation id books Plot ropes (2) Quarter ropes (2) extra data sheets on water-resistant paper Gloves Stadia rod 1.5 m measuring stick

End of Day Data sheets to Notebook Refill clipboards Check in all equipment Charge dead batteries Stakes for next day PROPORTIONS OF CANOPY/TRUNK/ROOT-BASE DIAMETER: 91-100% 1-10% 6 1 76-90% 11-25% 5 2

4 3 26-50% 51-75%

Tertiary & smaller branches Secondary branch Primary branch Main trunk/stem(s)

ELEPHANT IMPACT (Type) CODE Pulled or kicked out A Pushed over and dead or appears dead B QUANTIFY Main trunk broken, stump is or appears dead C AS FOLLOWS: Main trunk broken resprouting or likely to repsrout D 1-10% 1 Pushed over but still alive alive E 11-25% 2 Main trunk tusk-slashed F 26-50% 3 Main trunk debarked (% O ) G 51-75% 4 Roots exposed and eaten (% O ) H 76-90% 5 Primary branches broken J 91-100% 6 Secondary and/or smaller branches broken K None - no obvious LEAVE EMPTY

FIRE IMPACT (Assess only after a burn) Main stem(s) killed, entire plant dead, or apparently so A Main stem(s) killed but coppicing from ground level B Only debarked area of main stem burnt C Primary stems killed, no signs of re-sprouting D Primary stems killed, re-sprouting off main stems E Secondary and/or smaller branches killed, resprouting F None - no obvious impact Sabie River Study Site, preflood 1996.11.02

Sabie River Study Site, postflood 2000.08.03 note: photos have not been orthocorrected Letaba River Study Site, preflood 1996.11.04

Letaba River Study Site, postflood 2000.09.07

note: photos have not been orthocorrected Sabie River pre (1996.11.02) and post (2000.08.03) flood comparison of the channel near Nkuhlu Picnic Site Sabie River Site Map

Site Transect Plot HERBS Recorder Page Date Measurere

ID Species Tuft Diameter Pasture Meter

Site sketch

E Small herbs (<1cm) Diameter =

W

river Site Transect Plot WOODY Date Recorder Page Measurer Crown height Bulk height Lowest Foliage Canopy diam. Basal Diameter Bearing Distance (m) (m) (m) (m) (cm) (m) ID Species Distance Angle Distance Angle Distance Angle 1 2 circle if dead from mag N Notes Site Trancect Bearing GPS Date Page #

Slope Horiz.

Point Distance Bearing Description Distance Vert %

N=1 E=3 W=2 S=4