Thesis--Heidelberg. / Includes bibliographical references (p. 254-276).

Thesis--Hamburg. / Lebenslauf. "Literatur": p. 78-80.

Over the last two decades, there have been increasing concerns about environmental degradation and its consequences on the long-term sustainability of socio-economic systems around the world. The publication of the report of the Club of Rome in 1972, (Meadows et al. 1972) focused on the issue of limits to growth. Since then, there has been a profusion of literature and general models have been developed to address the causes of environmental degradation and the unsustainability of current patterns of growth (Ehrlich and Ehrlich 1970; 1990). Essentially these models used parameters that included population growth, consumption levels and aspects of technology, and their effects on the environment. While these models and studies were at a macro level that helped focus attention on the patterns of growth and their unsustainability, they did not provide insights into the mechanisms that were driving ecological change, nor suggest alternative models of growth. An entry point into the current study is to understand the mechanisms that drive ecological change. Motivated by concerns for environmental degradation, and the need to understand the mechanisms that drive ecological change, the study is situated in the academic domain of studies on human-nature interactions. The complex nature of interactions between human groups with their environment and their dependence on the situational context, requires that such studies be at a regional and local scale for which sufficient detail is available. This particular study is situated in the Nilgiri hills in the Western Ghats of Southern India for which such detailed information is available. The study reconstructs the ecological history of the Nilgiri area during the last 200 years, and from this laboratory of human-nature interactions, attempts to derive general patterns.

Soňa Bendíková:Soňa Bendíková:Soňa Bendíková:Soňa Bendíková: Kotas of Blue Mountains: Myths and LegendsKotas of Blue Mountains: Myths and LegendsKotas of Blue Mountains: Myths and LegendsKotas of Blue Mountains: Myths and Legends AbstractAbstractAbstractAbstract The dissertation The Kotas from the Blue Mountains: Myths and Legends deals with the tradition of the Kota tribe living in the Nilgiri mountain range in southern India. The work discusses the oral tradition of the tribe on the background of the regional development in the last two centuries. The Kotas used to live symbiotically with a few other local tribes with whom they developed a unique system of barter trade and services. The microregion remained isolated until new settlers started to arrive from the valley (in the beginning of 19th century). The arrival of the people from the valley and of the English people in the course of the last two hundred years caused a significant change of all aspects of life in the Blue Mountains: economic, social, cultural and ecological. This work has two aims: (i) to interpret the results of my fieldwork and to analyze the recordings of the remnants of the oral heritage of the tribe with approximately 2,000 members, and to do it on the background of the changes in the area; and (ii) to determine whether and how...

The Nilgiri tahr (Hemitragus hylocrius) is an endangered mountain ungulate endemic to the Western Ghats in South India. I studied the status and ecology of the Nilgiri tahr in the Mukurthi National Park, from January 1993 to December 1995. To determine the status of this tahr population, I conducted foot surveys, total counts, and a three-day census and estimated that this population contained about 150 tahr. Tahr were more numerous in the north sector than the south sector of the park. Age-specific mortality rates in this population were higher than in other tahr populations. I conducted deterministic computer simulations to determine the persistence of this population. I estimated that under current conditions, this population will persist for 22 years. When the adult mortality was reduced from 0.40 to 0.17, the modeled population persisted for more than 200 years. Tahr used grasslands that were close to cliffs (p <0.0001), far from roads (p <0.0001), far from shola forests (p <0.01), and far from commercial forestry plantations (p <0.001). Based on these criteria I mapped the suitability of tahr habitat using a GIS and estimated that only 20% of the park area had >50% chance of being used by tahr. I used the GIS to simulate several management options to improve the quality of tahr habitat. Suitable habitat for tahr increased two-fold when roads within the park were closed to vehicular access. Similarly, removal of commercial forestry plantations also resulted in a two-fold increase of suitable habitat, and finally when both road access was restricted and commercial forests were removed, suitable tahr habitat increased three-fold. I used micro-histological analysis on tahr fecal pellets to determine food habits. Grasses constituted 64.2% of their diet. Five plant species (Eulalia phaeothrix, Chrysopogon zeylanicus, Ischaemum rugosum, Andropogon sp., and Carex sp.) accounted for 84.6% of the tahr' diet. These species were found in higher densities in the grasslands of the north sector than the south sector of the park (p <0.001). Predators such as leopard (Panthera pardus) and tiger (Panthera tigris), killed and consumed tahr. Tahr constituted 56% of the leopards' diet and 6% of the tigers' diet. I estimated that leopards and tigers in the park killed and consumed 30 to 60 tahr per year, and this accounted for 19% to 38% of the tahr population. The tahr population in the park has undergone a decline, possible causes for this decline includes high mortality from predation and poaching and loss of habitat. / Ph. D.

A long-standing question in ecology is understanding how the environment structures species occupancy in space and time. Specifically, identifying associations between environmental drivers - climate and land cover - and species occupancy is crucial to predicting species distributional dynamics in the future. Over the last century, research on the abiotic drivers of species occupancy has largely focused on temperate regions. Tropical mountain ecosystems harbor extraordinary levels of diversity and face some of the highest anthropogenic pressures of climate and land cover change. Yet, such regions have remained historically understudied. Bird species, due to their sheer diversity and occurrence across climatic zones and land cover types, are an ideal model for understanding how climate and land cover structure occupancy in space and time. The goal of this dissertation is to disentangle spatial and temporal associations between environmental drivers - climate and land cover - and bird species occupancy along a tropical montane gradient. I use an integrative approach that relies on citizen science, historical ecology, and bioacoustics to study bird communities in the Western Ghats biodiversity hotspot of southern India. In Chapter 1, we used observations from the world’s largest citizen science database, eBird, to ask how contemporary climate and land cover are associated with bird species occupancy across the Nilgiri and the Anamalai hills of the Western Ghats. We show that the occupancy of several forest specialist birds was negatively associated with temperature seasonality, highlighting narrow thermal niches for such species. We also show that a small number of generalist bird species are positively associated with human-modified land cover types. In Chapter 2, we combined colonial-era and modern datasets on bird species observations and land cover to ask how a century of landscape change across the Nilgiri hills has impacted bird communities. Between 1848 and 2017, 75% of grassland habitat across the Nilgiri hills was lost toward timber plantation and cash crop expansion. Such drastic declines in grassland habitat have resulted in declines in species persistence and relative abundance of grassland specialist birds over the last century. As a result, the functional trait space has undergone biotic homogenization. In Chapter 3, we ask if the reversal of landscape changes significantly affects bird communities. Using passive acoustic monitoring, we examined the impacts of ecological restoration on bird communities and other vocalizing fauna along a gradient of forest regeneration (consisting of actively restored, naturally regenerating, and mature benchmark sites) in the Anamalai hills. Encouragingly, we show that the bird community composition of actively restored sites is transitioning toward mature benchmark sites. However, when we moved beyond birds, we found that vocalizations at higher frequencies (> 12 kHz) were largely missing from actively restored and naturally regenerating sites, while the same frequency space was occupied in mature benchmark sites. Taken together, we find that climate and land cover are key determinants of bird species occupancy in the Western Ghats, and in a globally changing world, conservation interventions such as ecological restoration along with the preservation of naturally occurring land cover types are key to sustaining montane avifauna in the long run.

Les sols humifères des “Hautes Terres” du massif des Nilgiri peuvent être considérés comme le résultat d'une évolution polycyclique : les altérites ferrallitiques correspondent à une ancienne pédogenèse sous climat tropical chaud et humide ; la pédogenèse actuelle n'expliquant que la formation des horizons humifères supérieurs.<br />Les sols les plus humifères sont caractérisés par la présence de grandes quantités d'associations organo-métalliques et vérifient les nouveaux critères d'appartenance aux Andosols des classifications des sols et sont, de plus, non-allophaniques.<br />Les Andosols des Nilgiri, développés sur un matériau ferrallitique ancien, présentent une pédogenèse originale. En l'absence de verres volcaniques et d'autres minéraux altérables dans le matériau ferrallitique de profondeur, les sources potentielles d'aluminium et de fer sont constituées par des oxydes. La gibbsite et les oxydes de fer, considérés comme minéraux ultimes de l'altération ferrallitique, sont instables en milieu acide et organique. La formation des associations organo-métalliques est due à l'acido-complexolyse de la gibbsite et des oxydes de fer. Du fait des fortes teneurs en oxydes, les associations organo-métalliques sont pourvues d'une forte charge métallique et s'accumulent dans le profil, ce qui conduit à l'apparition des propriétés andiques.<br />Les datations au 14C et la détermination du delta13C des horizons humifères ont mis en évidence que l'accumulation de matière organique était à relier à l'existence d'une période plus froide à la fin du Pléistocène sous une végétation graminéenne. <br />L'étude de ces sols présente un intérêt certain pour la compréhension des processus d'accumulation de carbone dans les sols à différentes époques, et montre que la caractérisation des associations organo-métalliques à différentes échelles permet de comprendre les mécanismes d'interaction entre la matière organique et les cations métalliques, clé de la stabilisation de la matière organique.

The oldest dated rocks from the Acasta gneisses of the western Slave Province, Canada present an igneous age of ~4030 Ma. Following this the detrital zircons from the Jack Hills, Narryer Gneiss Terrane, Yilgarn Craton, Western Australia are identified as 4404 ±8 Ma. These discoveries suggest that crustal formation started as early as the Priscian Eon. Hitherto the Earth has gone through a series of interactions involving the atmosphere, hydrosphere, crust, mantle and core. However, only limited remnants of these early processes remain on the accessible crust due to extensive crustal reworking. The Southern Granulite Terrane (SGT) in the southern part of India represents the most extensive exposure of lower crustal granulite terranes in the world. This study mainly focuses on the characteristics of Archean (~2500 Ma) tectonics and nature of subsequent crustal growth, which led to the formation of Archean Nilgiri Block. Detailed fieldwork in this terrane and subsequent petrographic analysis revealed charnockites, hornblende-biotite gneiss, metagabbro/mafic granulite, websterite, amphibolite, Grt-Ky metasediment, metatuff and banded iron formation as the main rock types in this terrane. Field and petrographic results show a regional trend with garnet-orthopyroxene-biotite-quartz-plagioclase-K- feldspar bearing charnockites in the southern part which gets subsequently enriched in clinopyroxene that forms garnet-absent two pyroxene granulites consisting of orthopyroxene-clinopyroxene-quartz-plagioclase-K-feldspar towards the central part. Further north, metagabbro/mafic granulite is enriched in garnet-clinopyroxene-plagioclase assemblage. Websterite, amphibolite, metasediment, metatuff and banded iron formation are stacked and closely associated within this mafic belt in the north. The metagabbro represents peak P-T conditions of ~850°C and ~14kbar compared to the charnockites, which recorded a peak P-T of ~850°C and 9-10kbar. Petrographic results of oxide minerals show that the southern charnockitic part is abundant in rutile-ilmenite association represent reduced conditions compared to the oxidized magnetite-hematite-ilmenite associations in the mafic rocks. This oxidation trend is followed by pyrrhotite-chalcopyrite enriched southern charnockitic region that transforms to pyrite rich northern mafic belt. Ilmenite¬titanite association with no sulphides characterizes the hornblende-biotite gneiss in the entire Nilgiri Block. The geochemical variations of major, trace and rare earth elements show that the granulite-amphibolite grade felsic rocks evolved in an arc magmatic process leaving behind mafic magma, which later intruded into these rocks, in a subduction related arc magmatic process. The U-Pb LA-ICPMS and SHRIMP dating of charnockite, hornblende-biotite gneiss and met gabbros shows ca. 2550 Ma formation age and ca. 2450 Ma metamorphism in this terrane.