@article{KalkuhlSchwerhoffWaha2020, author = {Kalkuhl, Matthias and Schwerhoff, Gregor and Waha, Katharina}, title = {Land tenure, climate and risk management}, series = {Ecological economics}, volume = {171}, journal = {Ecological economics}, publisher = {Elsevier Science}, address = {Amsterdam [u.a.]}, issn = {0921-8009}, doi = {10.1016/j.ecolecon.2019.106573}, pages = {16}, year = {2020}, abstract = {We analyze to what extent climate conditions affect the prevalence of sharecropping as a form of traditional land tenure. We investigate how sharecropping tenure is related to climate risk and how it interacts with fertilizer use and livestock ownership that both influence production risk. We first develop a stylized theoretical model to illustrate the role of climate for land tenure and production. Our empirical analysis is based on more than 9000 households with considerable heterogeneity in climate conditions across several African countries. We find that farmers in areas with low precipitation are more likely to be sharecroppers. We further find evidence for risk management interaction effects as sharecropping farmers are less likely to own livestock and more likely to use fertilizer. In economies where formal kinds of insurance are unavailable, sharecropping thus functions as a form of insurance and reduces the need for potentially costly risk management strategies.}, language = {en} } @article{MtilatilaBronstertVormoor2022, author = {Mtilatila, Lucy Mphatso Ng'ombe and Bronstert, Axel and Vormoor, Klaus Josef}, title = {Temporal evaluation and projections of meteorological droughts in the Greater Lake Malawi Basin, Southeast Africa}, series = {Frontiers in water}, volume = {4}, journal = {Frontiers in water}, publisher = {Frontiers Media}, address = {Lausanne}, issn = {2624-9375}, doi = {10.3389/frwa.2022.1041452}, pages = {16}, year = {2022}, abstract = {The study examined the potential future changes of drought characteristics in the Greater Lake Malawi Basin in Southeast Africa. This region strongly depends on water resources to generate electricity and food. Future projections (considering both moderate and high emission scenarios) of temperature and precipitation from an ensemble of 16 bias-corrected climate model combinations were blended with a scenario-neutral response surface approach to analyses changes in: (i) the meteorological conditions, (ii) the meteorological water balance, and (iii) selected drought characteristics such as drought intensity, drought months, and drought events, which were derived from the Standardized Precipitation and Evapotranspiration Index. Changes were analyzed for a near-term (2021-2050) and far-term period (2071-2100) with reference to 1976-2005. The effect of bias-correction (i.e., empirical quantile mapping) on the ability of the climate model ensemble to reproduce observed drought characteristics as compared to raw climate projections was also investigated. Results suggest that the bias-correction improves the climate models in terms of reproducing temperature and precipitation statistics but not drought characteristics. Still, despite the differences in the internal structures and uncertainties that exist among the climate models, they all agree on an increase of meteorological droughts in the future in terms of higher drought intensity and longer events. Drought intensity is projected to increase between +25 and +50\% during 2021-2050 and between +131 and +388\% during 2071-2100. This translates into +3 to +5, and +7 to +8 more drought months per year during both periods, respectively. With longer lasting drought events, the number of drought events decreases. Projected droughts based on the high emission scenario are 1.7 times more severe than droughts based on the moderate scenario. That means that droughts in this region will likely become more severe in the coming decades. Despite the inherent high uncertainties of climate projections, the results provide a basis in planning and (water-)managing activities for climate change adaptation measures in Malawi. This is of particular relevance for water management issues referring hydro power generation and food production, both for rain-fed and irrigated agriculture.}, language = {en} } @article{HeringHauptfleischKramerSchadtetal.2022, author = {Hering, Robert and Hauptfleisch, Morgan and Kramer-Schadt, Stephanie and Stiegler, Jonas and Blaum, Niels}, title = {Effects of fences and fence gaps on the movement behavior of three southern African antelope species}, series = {Frontiers in Conservation Science}, volume = {3}, journal = {Frontiers in Conservation Science}, publisher = {Frontiers}, address = {Lausanne, Schweiz}, issn = {2673-611X}, doi = {10.3389/fcosc.2022.959423}, pages = {1 -- 19}, year = {2022}, abstract = {Globally, migratory ungulates are affected by fences. While field observational studies reveal the amount of animal-fence interactions across taxa, GPS tracking-based studies uncover fence effects on movement patterns and habitat selection. However, studies on the direct effects of fences and fence gaps on movement behavior, especially based on high-frequency tracking data, are scarce. We used GPS tracking on three common African antelopes (Tragelaphus strepsiceros, Antidorcas marsupialis, and T. oryx) with movement strategies ranging from range residency to nomadism in a semi-arid, Namibian savanna traversed by wildlife-proof fences that elephants have regularly breached. We classified major forms of ungulate-fence interaction types on a seasonal and a daily scale. Furthermore, we recorded the distances and times spent at fences regarding the total individual space use. Based on this, we analyzed the direct effects of fences and fence gaps on the animals' movement behavior for the previously defined types of animal-fence interactions. Antelope-fence interactions peaked during the early hours of the day and during seasonal transitions when the limiting resource changed between water and forage. Major types of ungulate-fence interactions were quick, trace-like, or marked by halts. We found that the amount of time spent at fences was highest for nomadic eland. Migratory springbok adjusted their space use concerning fence gap positions. If the small home ranges of sedentary kudu included a fence, they frequently interacted with this fence. For springbok and eland, distance traveled along a fence declined with increasing utilization of a fence gap. All species reduced their speed in the proximity of a fence but often increased their speed when encountering the fence. Crossing a fence led to increased speeds for all species. We demonstrate that fence effects mainly occur during crucial foraging times (seasonal scale) and during times of directed movements (daily scale). Importantly, we provide evidence that fences directly alter antelope movement behaviors with negative implications for energy budgets and that persistent fence gaps can reduce the intensity of such alterations. Our findings help to guide future animal-fence studies and provide insights for wildlife fencing and fence gap planning.}, language = {en} } @article{ReinhardtLierschAbdeladhimetal.2018, author = {Reinhardt, Julia and Liersch, Stefan and Abdeladhim, Mohamed Arbi and Diallo, Mori and Dickens, Chris and Fournet, Samuel and Hattermann, Fred Fokko and Kabaseke, Clovis and Muhumuza, Moses and Mul, Marloes L. and Pilz, Tobias and Otto, Ilona M. and Walz, Ariane}, title = {Systematic evaluation of scenario assessments supporting sustainable integrated natural resources management}, series = {Ecology and society : a journal of integrative science for resilience and sustainability}, volume = {23}, journal = {Ecology and society : a journal of integrative science for resilience and sustainability}, number = {1}, publisher = {Resilience Alliance}, address = {Wolfville}, issn = {1708-3087}, doi = {10.5751/ES-09728-230105}, pages = {34}, year = {2018}, abstract = {Scenarios have become a key tool for supporting sustainability research on regional and global change. In this study we evaluate four regional scenario assessments: first, to explore a number of research challenges related to sustainability science and, second, to contribute to sustainability research in the specific case studies. The four case studies used commonly applied scenario approaches that are (i) a story and simulation approach with stakeholder participation in the Oum Zessar watershed, Tunisia, (ii) a participatory scenario exploration in the Rwenzori region, Uganda, (iii) a model-based prepolicy study in the Inner Niger Delta, Mali, and (iv) a model coupling-based scenario analysis in upper Thukela basin, South Africa. The scenario assessments are evaluated against a set of known challenges in sustainability science, with each challenge represented by two indicators, complemented by a survey carried out on the perception of the scenario assessments within the case study regions. The results show that all types of scenario assessments address many sustainability challenges, but that the more complex ones based on story and simulation and model coupling are the most comprehensive. The study highlights the need to investigate abrupt system changes as well as governmental and political factors as important sources of uncertainty. For an in-depth analysis of these issues, the use of qualitative approaches and an active engagement of local stakeholders are suggested. Studying ecological thresholds for the regional scale is recommended to support research on regional sustainability. The evaluation of the scenario processes and outcomes by local researchers indicates the most transparent scenario assessments as the most useful. Focused, straightforward, yet iterative scenario assessments can be very relevant by contributing information to selected sustainability problems.}, language = {en} } @article{WusterChirioTrapeetal.2018, author = {Wuster, Wolfgang and Chirio, Laurent and Trape, Jean-Francois and Ineich, Ivan and Jackson, Kate and Greenbaum, Eli and Barron, Cesar and Kusamba, Chifundera and Nagy, Zoltan T. and Storey, Richard and Hall, Cara and Wuster, Catharine E. and Barlow, Axel and Broadley, Donald G.}, title = {Integration of nuclear and mitochondrial gene sequences and morphology reveals unexpected diversity in the forest cobra (Naja melanoleuca) species complex in Central and West Africa (Serpentes: Elapidae)}, series = {Zootaxa : an international journal of zootaxonomy ; a rapid international journal for animal taxonomists}, volume = {4455}, journal = {Zootaxa : an international journal of zootaxonomy ; a rapid international journal for animal taxonomists}, number = {1}, publisher = {Magnolia Press}, address = {Auckland}, issn = {1175-5326}, doi = {10.11646/zootaxa.4455.1.3}, pages = {68 -- 98}, year = {2018}, abstract = {Cobras are among the most widely known venomous snakes, and yet their taxonomy remains incompletely understood, particularly in Africa. Here, we use a combination of mitochondrial and nuclear gene sequences and morphological data to diagnose species limits within the African forest cobra, Naja (Boulengerina) melanoleuca. Mitochondrial DNA sequences reveal deep divergences within this taxon. Congruent patterns of variation in mtDNA, nuclear genes and morphology support the recognition of five separate species, confirming the species status of N. subfulva and N. peroescobari, and revealing two previously unnamed West African species, which are described as new: Naja (Boulengerina) guineensis sp. nov. Broadley, Trape, Chirio, Ineich \& Wuster, from the Upper Guinea forest of West Africa, and Naja (Boulengerina) savannula sp. nov. Broadley, Trape, Chirio \& Wuster, a banded form from the savanna-forest mosaic of the Guinea and Sudanian savannas of West Africa. The discovery of cryptic diversity in this iconic group highlights our limited understanding of tropical African biodiversity, hindering our ability to conserve it effectively.}, language = {en} } @article{GonzalezFortesTassiTrucchietal.2019, author = {Gonzalez-Fortes, Gloria M. and Tassi, F. and Trucchi, E. and Henneberger, K. and Paijmans, Johanna L. A. and Diez-del-Molino, D. and Schroeder, H. and Susca, R. R. and Barroso-Ruiz, C. and Bermudez, F. J. and Barroso-Medina, C. and Bettencourt, A. M. S. and Sampaio, H. A. and Salas, A. and de Lombera-Hermida, A. and Fabregas Valcarce, Ram{\´o}n and Vaquero, M. and Alonso, S. and Lozano, Marina and Rodriguez-Alvarez, Xose Pedro and Fernandez-Rodriguez, C. and Manica, Andrea and Hofreiter, Michael and Barbujani, Guido}, title = {A western route of prehistoric human migration from Africa into the Iberian Peninsula}, series = {Proceedings of the Royal Society of London : B, Biological sciences}, volume = {286}, journal = {Proceedings of the Royal Society of London : B, Biological sciences}, number = {1895}, publisher = {Royal Society}, address = {London}, issn = {0962-8452}, doi = {10.1098/rspb.2018.2288}, pages = {10}, year = {2019}, abstract = {Being at the western fringe of Europe, Iberia had a peculiar prehistory and a complex pattern of Neolithization. A few studies, all based on modern populations, reported the presence of DNA of likely African origin in this region, generally concluding it was the result of recent gene flow, probably during the Islamic period. Here, we provide evidence of much older gene flow from Africa to Iberia by sequencing whole genomes from four human remains from northern Portugal and southern Spain dated around 4000 years BP (from the Middle Neolithic to the Bronze Age). We found one of them to carry an unequivocal sub-Saharan mitogenome of most probably West or West-Central African origin, to our knowledge never reported before in prehistoric remains outside Africa. Our analyses of ancient nuclear genomes show small but significant levels of sub-Saharan African affinity in several ancient Iberian samples, which indicates that what we detected was not an occasional individual phenomenon, but an admixture event recognizable at the population level. We interpret this result as evidence of an early migration process from Africa into the Iberian Peninsula through a western route, possibly across the Strait of Gibraltar.}, language = {en} } @article{NeiberKahlWiggeringetal.2019, author = {Neiber, Marco Thomas and Kahl, Sandra M. and Wiggering, Benedikt and Glaubrecht, Matthias}, title = {Adding the West-African riverine component}, series = {Zootaxa : an international journal of zootaxonomy ; a rapid international journal for animal taxonomists}, volume = {4674}, journal = {Zootaxa : an international journal of zootaxonomy ; a rapid international journal for animal taxonomists}, number = {3}, publisher = {Magnolia Press}, address = {Auckland}, issn = {1175-5326}, doi = {10.11646/zootaxa.4674.3.1}, pages = {301 -- 328}, year = {2019}, abstract = {While Africa's lacustrine gastropod fauna, in particular of Lake Tanganyika, has received much attention, the continent's riverine malacofauna has long been neglected. Pseudocleopatra is a relatively poorly known paludomid gastropod genus with species found throughout the lower reaches of the West African Volta and Congo rivers. In the course of ongoing systematic revisions of African paludomids, we present here a morphometric analysis and revision of the recent species assigned to the genus, i.e., P. togoensis, P. voltana, P. dartevellei and P. bennikei, to improve taxonomic acuity for this group. We use available museum material for geometric morphometrics, multivariate ratio analysis and comparisons of radular and opercular characters. Our results demonstrate that the four recent species of Pseudocleopatra are clearly distinguishable on the basis of ratios of shell measurements as well as radular and opercular characters. Pseudocleopatra has generic-level synapomorphies including: concentric opercula with relatively large paucispiral nuclei, and rachidian radular teeth with usually 13-20 cusps. On the basis of this characterisation, the nominal species Cleopatra broecki is transferred to Pseudocleopatra. Additionally, the nominal taxon P. bennikei is synonymized with P. broecki n. comb. The phylogenetic relationships of Pseudocleopatra are currently unknown, but the observed tendency of some fossil taxa assigned to Pseudocleopatra towards thalassoidism, i.e., the resemblance to marine gastropods, has led to the hypothesis that some of the thalassoid endemics in Lake Tanganyika may have originated from or be related to Pseudocleopatra. Should this hypothesis be correct, which is in need of testing by molecular genetic methods when suitable samples become available, Pseudocleopatra may play a crucial role in understanding of the evolution of thalassoidism in African Paludomidae.}, language = {en} } @phdthesis{Bibi2018, author = {Bibi, Faysal}, title = {Paleoecology and evolution in the Afro-Arabian neogene}, school = {Universit{\"a}t Potsdam}, year = {2018}, abstract = {This cumulative habilitation thesis presents new work on the systematics, paleoecology, and evolution of antelopes and other large mammals, focusing mainly on the late Miocene to Pleistocene terrestrial fossil record of Africa and Arabia. The studies included here range from descriptions of new species to broad-scale analyses of diversification and community evolution in large mammals over millions of years. A uniting theme is the evolution, across both temporal and spatial scales, of the environments and faunas that characterize modern African savannas today. One conclusion of this work is that macroevolutionary changes in large mammals are best characterized at regional (subcontinental to continental) and long-term temporal scales. General views of evolution developed on records that are too restricted in spatial and temporal extent are likely to ascribe too much influence to local or short-lived events. While this distinction in the scale of analysis and interpretation may seem trivial, it is challenging to implement given the geographically and temporally uneven nature of the fossil record, and the difficulties of synthesizing spatially and temporally dispersed datasets. This work attempts to do just that, bringing together primary fossil discoveries from eastern Africa to Arabia, from the Miocene to the Pleistocene, and across a wide range of (mainly large mammal) taxa. The end result is support for hypotheses stressing the impact of both climatic and biotic factors on long-term faunal change, and a more geographically integrated view of evolution in the African fossil record.}, language = {en} }