Despite ecological, anthropological, and archaeological debate surrounding their desirability as habitats for human occupation, tropical rainforests have received relatively little attention in discussions of Homo sapiens' Pleistocene dispersal. Sri Lanka has yielded some of the earliest dated fossil and material culture evidence (c. 38-35,000 cal. years BP) for our species in a modern rainforest context beyond Africa. Nevertheless, assertions in Sri Lanka, and elsewhere, regarding early human rainforest reliance have been largely based on coarse or 'off-site' palaeoenvironmental records, and the overall role of these environments in human subsistence strategies has remained uncertain. This study applies stable carbon and oxygen isotope analysis to Sri Lankan human fossil, and associated faunal, tooth enamel dated to between 36-29,000 and 3,000 cal. years BP, in order to directly test human rainforest resource reliance, reconstruct a stable isotope ecology, and develop 'on-site' palaeoenvironmental records for Late Pleistocene-Holocene Sri Lankan rainforest foragers. Stable carbon and oxygen isotope analysis of modern Sri Lankan primates, and stable carbon, oxygen, and nitrogen isotope analysis of modern plant samples from the Polonnaruwa Nature Sanctuary, are also performed to investigate the ecology of Sri Lankan primates on which Late Pleistocene-Holocene forager subsistence strategies were focused. The results demonstrate that Homo sapiens relied on rainforest resources in Sri Lanka from c. 36-29,000 cal. years BP until the Iron Age c. 3 cal. years BP, even when open environments, and their corresponding resources, were available. This remains the case through periods of evident environmental change at the Last Glacial Maximum and even upon the arrival of agriculture in the island's tropical forests. The primate stable isotope data prove difficult to interpret as ecological niche separation in the absence of observation data. Nonetheless, humans were evidently able to not only use but also rapidly specialise in the exploitation of South Asia's rainforests.

The area studied at Fern Kloof, near Grahamstown, consists of a strip of vegetation approximately 260 yds. long and 50 yds. wide, in which there are two communities: 1) indigenous forest 2) exotic Pine forest (which has only one tree species Pinus pinaster). Throughout the thesis this species is referred to as the pine. The object of the investigation has been to determine whether these communities are natural or not. This has involved a study of the floristic composition, the life forms and the structure of the plant communities. In addition, various soil and environmental factors have been studied.

Human appropriation of natural resources, and the consequent loss of habitats, means that ecological restoration may in the future become a vital conservation tool. For this to happen, we have to understand the processes and factors that govern community assembly, and their management. Here I analyze data on community structure (richness, evenness, diversity, composition) of assemblages (millipedes, spiders, dung beetles, plants, birds, rodents), and on soil chemical and physical properties, to describe and evaluate post-disturbance dune forest regeneration patterns. Data were collected from program of a dune mining company), from post-mining rehabilitating dune forests, and from self-regenerating dune forests in northern KwaZulu-Natal. Both succession theory and community assembly theory predict that a species' niche will determine when it will colonize new sites, and by extension, what the eventual species composition will be. This type of control should result in deterministic regeneration patterns for a community. In support of this view, I found that the majority of habitat-age related changes in community structure and ecosystem function were either towards benchmark values (and will reach these values in less than 65 years post-disturbance), or were already equal to the benchmark. Age-related trajectories were repeatable between surveys and post-mining sites were changing as fast or faster than spontaneously regenerating sites. Moreover, detailed analysis of changes in community composition of millipedes, dung beetles, herbs, trees, birds and rodents showed that all of the taxa were also regaining the benchmark's species composition. However, community change was dependent on how it was measured - dung beetles recovered only species presence, but others relative abundances as well. Changes were almost never exponential, suggesting that colonization and extinction are not the orderly events foreseen by equilibrium biodiversity theory. Furthermore, the average abundances of birds, trees and millipedes in undisturbed dune forest patches were correlated with colonization success, suggesting that post-disturbance recovery through colonization may be controlled from outside the local community, rather than by species interactions. The recovery of the spider community appeared to be towards the benchmark forest community, but spider species composition was critically linked to microhabitat structure. Because microhabitat is not necessarily restored concurrently with forest community structure, the spider assemblage (and possibly other invertebrates) may not recover the desired pre-disturbance structure or composition. Dune forests thus seem to be resilient to mining disturbances, since most taxa were recovering structure and composition. However, classic successional and community assembly theories are unlikely to fully explain these community recovery mechanisms. More likely, post-disturbance recovery occurs because a new habitat passively "samples" the rain of dispersing propagules and individuals, leading to a high probability of capturing the average species composition of the region. A conceptual model of dispersal in the landscape suggested that species composition of new habitats might equilibrate to the composition of the closest habitat undergoing the least amount of species compositional change, although this may not apply to all taxa. This model may serve as the basis for directing future research and restoration management. / Thesis (DPhil (Zoology))--University of Pretoria, 2006. / Zoology and Entomology / unrestricted

This thesis will discuss how the application of place theory might provide insight into how a selection of Xhosa-speaking people in a rural village (Ntloko), in the former Ciskei of the Eastern Cape, interact with and establish relationships with the local indigenous thicket forest (ihlathi). I am concerned with how these influence residents' perceptions and attitudes (relational epistemologies) towards this resource, and how these may (or may not) translate into conservation practices. I am also interested in how socio-political and economic changes have altered these people/place relations (including gender) and their corresponding cultural perceptions. It is argued that the local thicket forest's significance and importance moves beyond the economic and utilitarian value of its natural resources. The thicket plays an important part in local identity construction, due to both its socio-cultural significance and its role in local livelihoods. People form meaningful attachments and relationships (relational epistemologies ) with the thicket as a place, through their interactions with it. While this may or may not result in actions and attitudes in-line with the conservation agenda, it is shown that this relationship is necessary for a local concern and stake in the natural environment. Those who have no or minimal interaction, such as many of the young women of Ntloko, have no opportunity to forge a relationship with it. Ihlathi may be known through narrative, but not personal experience, and as such no significant attachments can be formed, and thus concern for its conservation status is irrelevant. It is clear that if you remove people from an environment, you remove the stake they hold in the environment in question, thereby disrupting the relationship, and alienating people from nature. While a relational epistemology may not equate to conservation practices, it does imply a stake or concern in the environment, and as such, may provide an opportunity for conservationists to work with local communities. Resistance to conservation and development projects that aim to exclude local interaction, and therefore relationships, with the environment, will always be strong when local identities are intricately tied to the places and experiences that form them. Threatening that relationship threatens local identities and the attachments that orient them.

No description available.

As the human population in Florida continues to expand, development follows, and tree farms give way to homes and businesses. As parks are established, restoration of these semi-natural plantations may provide critical habitat for species conservation. This study evaluates vegetation response to restoration treatments at two study sites, formerly tree farms, now preserves in NE Florida. Treatments included thinning, clearing, or control (no treatment) within 10m^2 plots. Thinning reduced tree canopy to 20% (2-3 pines/plot) and removed all other vegetation; clearing treatments removed all biomass to bare soil; no herbicides were used. Within these plots richness and abundance was assessed by establishing two parallel transects and counting ramets on a bi-annual basis. Tree diameter at breast height (dbh) was also measured (cm). It was hypothesized that release of resources (thinning and clearing) would increase overall diversity (more so in graminoids and forbs), and encourage more robust tree growth versus control groups. Diversity ANOVA (Simpons & Shannon indices) showed significant differences due to survey date (p< 0.05) at the McGirts Creek site and a significant (p= 0.056) effect for the interaction term at the Tigers Point site. Tree dbh also increased at a significantly greater rate in thinned, versus control groups at the Tigers Point site (p= 0.03) perhaps due to higher initial tree density, but not at the McGirts Creek site (p= 0.85). Placing species into guilds revealed both sites reflected high levels of graminoids in cleared plots, which is consistent with early successional species (pioneer plants). McGirts followed hypothesis as forbs and graminoids were dominant in both thinned and cleared plots and the Tigers Point site had higher levels of vines and shrubs than expected. Restoration goals of increasing vegetative diversity, especially in r-selected species, and robust growth can be met by techniques used in this study.

Forests are more than a stand of trees in the landscape. They represent a complex, functional system of interacting and often interdependent biological, physical and chemical components (Kimmins 1997). In the past, complex interactions were increasingly recognized over time as food webs, abiotic processes and biotic feedbacks since then defined as the forest ecosystem. Trees grow in a world of multitrophic interactions (van der Putten et al. 2001). One component of this functional system is represented in several aspects by spiders and insects, as they contribute considerably to the biodiversity and ecosystem functioning in forest habitats (Watt et al. 1997). There is knowledge on the community composition of several forests of different stand type or tree species composition referring to soil dwelling arthropods. Moreover, studies often highlight the orientation of single arthropod species on abiotic factors or the composition of species assemblages in case studies; these represent ecologically well described groups that can be used as indicators of habitat quality (Pearce and Venier 2006; Cardoso et al. 2004). Evidence on the scale of interactions between the species and their environment are rare. This applies particularly to examples based on fine spatial and temporal scales.:Zusammenfassung 1 Summary 4 Chapter 1 General Introduction 7-19 1.1 Arthropods as a permanent component of forest ecosystems 7 1.2 Spiders and carabids in forest ecosystems 10 1.3 Are spiders and carabids in ecosystems dispensable? – functional diversity in natural antagonists 13 1.4 Objectives 20 Chapter 2 Influence of environmental parameters on small-scale distribution of soil-dwelling spiders in forests: what makes the difference, tree species or microhabitat? 23 2.1 Abstract 23 2.2 Introduction 24 2.3 Methods and materials 25 2.4 Results 32 2.5 Discussion 45 2.6 Conclusions 51 Chapter 3 Microhabitat heterogeneity in temperate forests: is distance to stems affecting ground-dwelling spider communities? 61 3.1 Abstract 61 3.2 Introduction 62 3.3 Materials and Methods 63 3.4 Results 68 3.5 Discussion 77 Chapter 4 The impacts of seasonality, forest type and succession on the community structure of temperate-forest ground beetles. 88 4.1 Abstract 88 4.2 Introduction 90 4.3 Methods and materials 92 4.4 Results 98 4.5 Discussion 113 4.6 Conclusions 120 Chapter 5 Is the age of forest habitats affecting the reproductive rate of generalist predatory ground beetle species? 129 5.1 Abstract 129 5.2 Introduction 131 5.3 Methods and materials 133 5.4 Results 138 5.5 Discussion 150 5.6 Conclusions 153 Chapter 6 General Discussion 161 6.1 Management effect 169 6.2 Future prospect 170 Liste der Veröffentlichtungen 173-174 Danksagung

Tropical forests, which provide important ecosystem functions and services, are increasingly threatened by anthropogenic pressures. This has resulted in an urgent need to understand tree species diversity of those forests. Where knowledge of that diversity is largely from the botanical surveys and local ecological studies, data must inevitably be up-scaled from point observations to the landscape and regional level if a holistic perspective is required. This thesis explores aspects of the spatio-temporal heterogeneity of canopy reflectance patterns over the forests of French Guiana, in order to assess whether this information could help defining an ecologically consistent forest typology. To gain insight into both the spatial and temporal heterogeneity of French Guiana’s forests, instrumental artefacts affecting the satellite data first had to be addressed. Data used in this study represent the spectral response of forest canopies, and the way in which such data are captured makes them susceptible to the ‘bi-directional reflectance distribution function’ (BRDF). BRDF indicates that objects do not reflect light in equal proportions in all directions (isotropically). Thus, forest canopies will reflect light anisotropically depending on factors including canopy roughness, leaf optical properties and inclination, and the position of the sun relative to the sensor. The second chapter of this thesis examines how BRDF affects the canopy reflectance of forests in French Guiana, and how not correcting for BRDF affects spectral classifications of those forests. When monthly reflectance data corrected for the artefact are examined, these suggest seasonally-occurring changes in forest structure or spectral properties of French Guiana’s forests. The third chapter of this thesis thus examines temporal effects of BRDF, and used cross-regional comparisons and plot-level radiative transfer modelling to seek to understand the drivers of the monthly variation of the forests’ canopy reflectance. For the latter, the Discrete Anisotropic Radiative Transfer (DART) model was used along with aerial laser scanning (ALS) observations over different forest structures, indicating that the observed variation in reflectance (and derivatives known as vegetation indices) could not be explained by monthly variations in solar direction. At the regional scale, it was also demonstrated that forests in the Guiana Shield possess temporal variation distinct from forests in central Africa or northern Borneo, forests also lying just above the Equator. Had the observed temporal variation in vegetation indices been the result of BRDF, it would have been expected that the forests in the three zones would have similar patterns of variation, which they did not. Central African forests appear to have their greening synchronized with rainfall, whereas forests in the Guianas appear synchronized with the availability of solar radiation. Further analysis of the vegetation index time-series of observations also indicated that different types of forests in French Guiana possess distinct patterns of temporal variation, suggesting that tropical forest types can be discriminated on the basis of their respective “temporal signatures.” That was exploited in the fourth chapter of the thesis, which maps forests in French Guiana based on their combined spatio-temporal canopy reflectance patterns and by so doing presents a novel way of addressing forest typology, based on ecologically meaningful information. The thesis presented demonstrates that it is possible to adequately address remote sensing data artefacts to examine patterns of spatial and temporal variation in tropical forests. It has shown that phenological patterns of tropical rainforests can be deduced from remote sensing data, and that forest types can be mapped based on spatio-temporal canopy reflectance patterns. It is thus an important contribution to understand the ecology of tropical forests in French Guiana and to improve the toolbox of scientists dealing with the identification of spatio-temporal patterns observable in forests at the landscape level.

Fire is a fundamental environmental factor that directly shapes many terrestrial ecosystems on Earth. The present thesis attempts to provide a comprehensive overview of the fire dynamics in Central Europe over the course of the last 12,000 years. Based on extensive analyses of charcoal particles deposited in terrestrial and lacustrine sedimentary sequences and carbonized plant tissues deposited in soils, I was able to track past fire dynamics across a range of spatial scales - from the forest stand scale to the landscape scale. First, we described relationships between drivers of recent fire occurrence and proposed linkages to the spatial pattern of Late-Holocene biomass burning. We found factors related to relief characteristics, such as increased thermal flux or terrain roughness, to be important determinants of fire occurrence within the present-day landscape. Contrary to all expectations, anthropogenic drivers seem to have a weak influence at present. Because relief-based factors have been stable throughout the Holocene, it seems probable that habitats of certain types are more predisposed to increased burning. We hypothesized that recurrent fire disturbances may contribute to the long-term maintenance of Pinus sylvestris-dominated forests, which withstood the competitive pressure of broadleaf...

No description available.