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DDC: 550 × Subject: Animalia ×

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    The environmental and evolutionary history of Lake Ohrid (FYROM/Albania): interim results from the SCOPSCO deep drilling project
    (Katlenburg-Lindau : European Geosciences Union, 2017) Wagner, Bernd; Wilke, Thomas; Francke, Alexander; Albrecht, Christian; Baumgarten, Henrike; Bertini, Adele; Combourieu-Nebout, Nathalie; Cvetkoska, Aleksandra; D'Addabbo, Michele; Donders, Timme H.; Föller, Kirstin; Giaccio, Biagio; Grazhdani, Andon; Hauffe, Torsten; Holtvoeth, Jens; Joannin, Sebastien; Jovanovska, Elena; Just, Janna; Kouli, Katerina; Koutsodendris, Andreas; Krastel, Sebastian; Lacey, Jack H.; Leicher, Niklas; Leng, Melanie J.; Levkov, Zlatko; Lindhorst, Katja; Masi, Alessia; Mercuri, Anna M.; Nomade, Sebastien; Nowaczyk, Norbert; Panagiotopoulos, Konstantinos; Peyron, Odile; Reed, Jane M.; Regattieri, Eleonora; Sadori, Laura; Sagnotti, Leonardo; Stelbrink, Björn; Sulpizio, Roberto; Tofilovska, Slavica; Torri, Paola; Vogel, Hendrik; Wagner, Thomas; Wagner-Cremer, Friederike; Wolff, George A.; Wonik, Thomas; Zanchetta, Giovanni; Zhang, Xiaosen S.
    This study reviews and synthesises existing information generated within the SCOPSCO (Scientific Collaboration on Past Speciation Conditions in Lake Ohrid) deep drilling project. The four main aims of the project are to infer (i) the age and origin of Lake Ohrid (Former Yugoslav Republic of Macedonia/Republic of Albania), (ii) its regional seismotectonic history, (iii) volcanic activity and climate change in the central northern Mediterranean region, and (iv) the influence of major geological events on the evolution of its endemic species. The Ohrid basin formed by transtension during the Miocene, opened during the Pliocene and Pleistocene, and the lake established de novo in the still relatively narrow valley between 1.9 and 1.3 Ma. The lake history is recorded in a 584 m long sediment sequence, which was recovered within the framework of the International Continental Scientific Drilling Program (ICDP) from the central part (DEEP site) of the lake in spring 2013. To date, 54 tephra and cryptotephra horizons have been found in the upper 460 m of this sequence. Tephrochronology and tuning biogeochemical proxy data to orbital parameters revealed that the upper 247.8 m represent the last 637 kyr. The multi-proxy data set covering these 637 kyr indicates long-term variability. Some proxies show a change from generally cooler and wetter to drier and warmer glacial and interglacial periods around 300 ka. Short-term environmental change caused, for example, by tephra deposition or the climatic impact of millennial-scale Dansgaard-Oeschger and Heinrich events are superimposed on the long-term trends. Evolutionary studies on the extant fauna indicate that Lake Ohrid was not a refugial area for regional freshwater animals. This differs from the surrounding catchment, where the mountainous setting with relatively high water availability provided a refuge for temperate and montane trees during the relatively cold and dry glacial periods. Although Lake Ohrid experienced significant environmental change over the last 637 kyr, preliminary molecular data from extant microgastropod species do not indicate significant changes in diversification rate during this period. The reasons for this constant rate remain largely unknown, but a possible lack of environmentally induced extinction events in Lake Ohrid and/or the high resilience of the ecosystems may have played a role. © Author(s) 2017.
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    Agriculture, livelihoods and climate change in the West African Sahel
    (Heidelberg : Springer Verlag, 2011) Sissoko, K.; van Keulen, H.; Verhagen, J.; Tekken, V.; Battaglini, A.
    The West African Sahel is a harsh environment stressed by a fast-growing population and increasing pressure on the scarce natural resources. Agriculture is the main source of livelihood of the majority of the people living in the area. Increases in temperature and/or modifications in rainfall quantities and distribution will substantially impact on the natural resource on which agriculture depends. The vulnerability of livelihoods based on agriculture is increased and most likely exacerbate and accelerate the current 'downward spiral' of underdevelopment, poverty and environmental degradation. Notably, droughts, a short rainy season and/or very low rainfall will be felt by current systems. To cope with the difficult climatic situation, farm households have developed a range of strategies including selling of animals and on-farm diversification or specialization. At regional level, early warning systems including an operational agro-meteorological information system already provide farmers with crucial information. Substantial political, institutional and financial efforts at national and international level are indispensable for the sustenance of millions of lives. In terms of development, priority needs to be given to adaptation and implementation of comprehensive programs on water management and irrigation, desertification control, development of alternative sources of energy and the promotion of sustainable agricultural practices by farmers.