@phdthesis{Konrad2015,
  author    = {Konrad, Tillmann},
  title     = {Governance of Protected Areas in West Africa - The case of the W-Arly-Pendjari (WAP) Complex in Benin and Burkina Faso},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-115331},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2015},
  abstract  = {Protected areas are the central strategy for preserving biodiversity in the face of overexploitation and global change. To ensure their long-term survival, however, these areas may not be regarded as last havens of wilderness, but as complex social-ecological systems. Modern approaches of protected area (PA) management support this view by balancing conservation and development issues in a sustainable way and adapted to the local context. However, success of these strategies in achieving their aims so far remains limited. This study therefore aimed at analysing processes and outcomes of PA co-management approaches implemented in a large transfrontier conservation area in West Africa. The W-Arly-Pendjari (WAP) complex spans over more than 30.000 square km in Benin, Burkina Faso and Niger and is composed of approximately 20 subunits. Due to national legal and administrative variety as well as a high diversity of local (project) implementation approaches, the general setting resembled a quasi-experimental design facilitating comparative studies. A mix of quantitative (e.g. survey of 549 households) and qualitative (e.g. expert interviews, literature review) methods was used to evaluate the institutional and organisational differences of PA management approaches implemented in the different parts of WAP belonging to Benin and Burkina Faso. I included an analysis of contextual factors (e.g. land-cover-change) and ecological data, but concentrated on the role of local resource users within the co-management arrangements and the effectiveness of governance regimes to deliver positive socio-economic outputs. Exploring the question whether promotion of development in PA surroundings indeed stipulates conservation success (and vice versa) remained challenging: the lack of sound ecological data, a general mismatch of spatial scale in existing data sets, as well as the high complexity of realities on the ground made me refrain from using simplified proxy indicators and (statistical) modelling approaches. I found that the Sudano-Sahelian context is a very difficult one for the implementation of effective participation approaches in the short-term. Political, demographic, socio-economic as well as ecological factors generated a very dynamic situation characterized by limited financial and natural resources as well as weak institutional and organisational settings. Arenas of interaction were often marked rather by a high degree of distrust and competition than by cooperation among actors. Amid all rhetoric, participation in most cases was hence limited to the transfer of (sparse) information, regulated resource access and financial funds. Options for participation of local resource users in decision-making arenas were generally scarce. Underlying processes were dominated by opacity and often low accountability of actors on all levels. Negative, but also positive affection of local residents by PA existence and management hence was high. Governance regimes of the complex performed very differently with regard to their ability of effectively empowering local village participatory bodies (vpb), generating and distributing benefits to individuals and village communities as well as providing mechanisms of conflict resolution. People around Pendjari enjoyed a relative wealth of high value benefits, while negative impacts caused by human-wildlife conflicts were widespread around the complex. Autochthonous farmers usually were better integrated in incentive schemes than were newcomers or herders. While there was functional separation of actors' roles in all parts of WAP, these roles differed significantly between blocks. Existence and functioning of village participatory bodies ameliorated the situation for local resource users fundamentally, as they acted as cut-points between different networks (governmental hierarchies, private concessionaires and local resource users). Vpbs in the Pendjari region proved to be most advanced in their capacity to push resource users' claims in action arenas on the micro-level. Via their union, these associations also managed to impact arenas on the meso- and the macro scale. Project interventions often had catalyst functions to empower local resource users and their vbps. However, they also contributed to social imbalance and intra-organisational competition. My results represent a snapshot of an ongoing process to establish effective co-governance regimes in the WAP-area. Though I identified a large scope of shortcomings, there were also very promising initiatives underway. This work is therefore meant to foster future research and further positive development by giving guidance scholars and decision-makers form the local to the global level alike.},
  subject      = {Gesch{\"u}tzte Natur},
  language  = {en}
}
@phdthesis{NoellieAhouRUETH2010,
  author    = {Noellie Ahou RUETH, geb. YAO},
  title     = {Mapping Bushfire Distribution and Burn Severity in West Africa Using Remote Sensing Observations},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-54244},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2010},
  abstract  = {Fire has long been considered to be the main ecological factor explaining the origin and maintenance of West African savannas. It has a very high occurrence in these savannas due to high human pressure caused by strong demographic growth and, concomitantly, is used to transform natural savannas into farmland and is also used as a provider of energy. This study was carried out with the support of the BIOTA project funded by the German ministry for Research and Education. The objective of this study is to establish the spatial and temporal distribution of bushfires during a long observation period from 2000 to 2009 as well as to assess fire impact on vegetation through mapping of the burn severity; based on remote sensing and field data collections. Remote sensing was used for this study because of the advantages that it offers in collecting data for long time periods and on different scales. In this case, the Moderate Resolution Imaging Spectroradiometer (MODIS) satellite instrument at 1km resolution is used to assess active fires, and understand the seasonality of fire, its occurrence and its frequency within the vegetation types on a regional scale. Landsat ETM+ imagery at 30 m and field data collections were used to define the characteristics of burn severity related to the biomass loss on a local scale. At a regional scale, the occurrence of fires and rainfall per month correlated very well (R2 = 0.951, r = -0.878, P < 0.01), which shows that the lower the amount of rainfall, the higher the fire occurrence and vice versa. In the dry season, four fire seasons were determined on a regional scale, namely very early fires, which announce the beginning of the fires, early and late fires making up the peak of fire in December/January and very late fires showing the end of the fire season and the beginning of the rainy season. Considerable fire activity was shown to take place in the vegetation zones between the Forest and the Sahel areas. Within these zones, parts of the Sudano-Guinean and the Guinean zones showed a high pixel frequency, i.e. fires occurred in the same place in many years. This high pixel frequency was also found in most protected areas in these zones. As to the kinds of land cover affected by fire, the highest fire occurrence is observed within the Deciduous woodlands and Deciduous shrublands. Concerning the burn severity, which was observed at a local scale, field data correlated closely with the ΔNBR derived from Landsat scenes of Pendjari National Park (R2 = 0.76). The correlation coefficient according to Pearson is r = 0.84 and according to Spearman-Rho, the correlation coefficient is r = 0.86. Very low and low burn severity (with ΔNBR value from 0 to 0.40) affected the vegetation weakly (0-35 percent of biomass loss) whereas moderate and high burn severity greatly affected the vegetation, leading to up to 100 percent of biomass loss, with the ΔNBR value ranging from 0.41 to 0.99. It can be seen from these results that remotely sensed images offer a tool to determine the fire distribution over large regions in savannas and that the Normalised Burn Ratio index can be applied to West Africa savannas. The outcomes of this thesis will hopefully contribute to understanding and, eventually, improving fire regimes in West Africa and their response to climate change and changes in vegetation diversity.},
  subject      = {Westafrika},
  language  = {en}
}
@phdthesis{Ernst2006,
  author    = {Ernst, Raffael},
  title     = {Anuran communities on the cutting edge : Analysing patterns and processes in anthropogenically altered tropical forests - Studies from the Guiana Shield and West Africa},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-18373},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2006},
  abstract  = {Summary Timber harvesting is currently the most common commercial utilisation activity in tropical forests. Assessing the effects of logging on different aspects of biodiversity and general ecosystem properties is hence of prime importance if the few remaining areas of intact tropical forest are to be protected effectively and efficiently. Tropical amphibian communities are an appropriate model system for studies on the impacts of human-induced environmental changes on the dynamics of complex biological systems. This thesis elaborates on patterns of diversity changes in tropical forest amphibian communities facing habitat alterations associated with selective logging in two globally important eco-regions (C{\^o}te d'Ivoire, Upper Guinea, West Africa and Guyana, the Guiana Shield, northern South America). The thesis is organised along two main themes. After a general introduction, a section on general methodology and an introduction to the model systems studied, the first theme moves from general patterns to underlying processes. A second theme running through both chapters carries from undisturbed systems to disturbed systems. A final section integrates findings and addresses implications for conservation management of anthropogenically altered tropical forests. Several case studies at the species- population and community level are being presented and data on the direct and indirect impacts of anthropogenic habitat alteration on respective organizational levels are provided. A key statement that is stressed on throughout the studies is the fact that common measures of diversity, such as species richness and species-diversity only inadequately reflect processes of diversity change following anthropogenic disturbance. They also fail to describe actual impacts on the dynamics of complex biological systems. It is argued that commonly used measures produce an incoherent and insufficient picture of diversity patterns and the underlying processes that shape these patterns. Thus, an understanding of higher levels of diversity, such as \&\#946;-diversity and functional diversity (and hence compositional patterns) appears to be the key to effectively mitigating the impacts of human-induced disturbance on amphibian communities. It is shown that the predictability of amphibian community composition depends on the respective level of anthropogenic disturbance imposed on a particular habitat. Hence, human activities that lead to changes in the structure of a forest, such as logging, not only alter simple system descriptors, such as the number of species in a given community, but rather alter the dynamics of the entire system. In this context, functional diversity is shown to be an important aspect underlying the actual mechanism that leads to the observed change of predictability patterns. Functional differences between species, rather than number of species per se appear to be the decisive factor in sustaining desirable ecosystem states and thus in maintaining important ecosystem services. Because biological diversity appears to play a substantial role in ecosystem resilience required to safeguard essential ecosystem functions in the face of environmental change, the thesis calls for a critical revision of common diversity assessments approaches. The studies advocate the reconsideration of the uncritical use of widespread measures and descriptors of biodiversity on grounds of inconsistent patterns found throughout numerous studies, including those presented herein.},
  subject      = {Tropischer Regenwald},
  language  = {en}
}
@phdthesis{Obermaier2000,
  author    = {Obermaier, Elisabeth},
  title     = {Coexistence and resource use in space and time in a West African tortoise beetle community},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-1815},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2000},
  abstract  = {Tropical rain forests and coral reefs are usually regarded as the epitome of complexity and diversity. The mechanisms, however, that allow so many species to coexist continuously, still need to be unraveled. Earlier equilibrium models explain community organization with a strict niche separation and specialization of the single species, achieved mainly by interspecific competition and consecutive resource partitioning. Recent non-equilibrium or stochastic models see stochastic factors ("intermediate disturbances") as more important. Such systems are characterized by broad niche overlaps and an unpredictable species composition. Mechanisms of coexistence are most interesting where species interactions are strongest and species packing is highest. This is the case within a functional group or guild where species use similar resources. In this project a community of seven closely related leaf beetle species (Chrysomelidae: Cassidinae) was investigated which coexist on a common host plant system (fam. Convovulaceae) in a tropical moist savanna (Ivory Coast, Como{\´e}-Nationalpark). A broad overlap in the seasonal phenology of the leaf beetle species stood in contrast to a distinct spatial niche differentiation. The beetle community could be separated in a savanna-group (host plant: Ipomoea) and in a river side group (host plant: Merremia). According to a correspondence analysis the five species at the river side, using a common host plant, Merremia hederacea, proved to be predictable in their species composition. They showed a small scale niche differentiation along the light gradient (microhabitats). Laboratory studies confirmed differences in the tolerance towards high temperatures (up to 50°C in the field). Physiological trade-offs between phenology, microclimate and food quality seem best to describe patterns of resource use of the beetle species. Further a phylogeny based on mt-DNA sequencing of the beetle community was compared to its ecological resource use and the evolution of host plant use was reconstructed},
  subject      = {Westafrika},
  language  = {en}
}
@phdthesis{Lampert2001,
  author    = {Lampert, Kathrin P.},
  title     = {Alternative life history strategies in the West African reed frog, Hyperolius nitidulus},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-1677},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2001},
  abstract  = {Distinct juvenile behaviour differences, changes in adult sizes and reproductive capacity and a long reproductive period triggered the working hypothesis of two alternative life-cycle strategies favouring aestivation or immediate reproduction. The hypothesis for the life-cycles of Hyperolius nitidulus that differed from the commonly assumed reproductive strategy for this species was confirmed by the results of this study. Aestivated juveniles start to mature at the beginning of the rainy season and reproduce subsequently. Their tadpoles grow until metamorphosis and either reproduce in this same season, in which case their offspring aestivates (one year - two generations), or they delay reproduction to the following year and aestivate themselves (one year - one generation). Juveniles trying to reproduce as fast as possible will invest in growth and differentiation and show no costly adaptations to aestivation, while juveniles delaying reproduction to the following rainy season will be well adapted to dry season conditions. Indirect evidence for the existence of a second generation was found in all three investigation years: adult size decreased abruptly towards the end of the rainy season, mainly due to the arrival of very small individuals, and clutch size decreased abruptly. Also at the end of the rainy season juveniles had two behavioural types: one hiding on the ground and clearly avoiding direct sunlight and another sitting freely above ground showing higher tolerance towards dry season conditions (high air temperatures and low humidity). Skin morphology differed between the types showing many more purine crystals in a higher order in the dry-season adapted juveniles. The final proof for the existence of a second generation came with the recapture of individuals marked as juveniles when they left the pond. The 45 recaptured frogs definitely came back to the pond to reproduce during the same season in 1999. Second generation frogs (males and females) were significantly smaller than the rest of all adults and egg diameter was reduced. Clutch size did not differ significantly. It was found that females did not discriminate against second generation males when coming to the ponds to reproduce. Second generation males had a similar chance to be found in amplexus as first generation males. Indirect and direct evidence for a second generation matched very well. The sudden size decrease in adults occurred just at the time when the first marked frogs returned. The observation that freshly metamorphosed froglets were able to sit in the sun directly after leaving the water led to the assumption that the decision whether to aestivate or to reproduce already happens during the frogs' larval period. Water chemistry and the influence of light was investigated to look for the factors triggering the decision, but only contaminated water increased the number of juveniles ready for aestivation. Whether the life history polymorphism observed in Hyperolius nitidulus is due to phenotypic plasticity or genetic polymorphism is still not known. Despite this uncertainty, there is no doubt that the optimal combination of different life histories is profitable and may be a reason for the wide range and high local abundance of Hyperolius nitidulus.},
  subject      = {Westafrika},
  language  = {en}
}