126 research outputs found
Testing Non‐Equilibrium Theory: Effects of Grazing on Plant Community Composition and Soil Nutrient Availability in Dry Southern Mongolian Steppes
Is Degradation a Major Problem in Semi-Desert Environments of the Gobi Region in Southern Mongolia?
This paper tests predictions derived from the non-equilibrium theory of rangeland science. Data were collected in livestock enclosures situated in the relatively moist desert steppes of the Gobi Gurvan Saykhan region of southern Mongolia from 2000 to 2003. Plant community composition and species’ richness in enclosures showed clear differences between years, but these were equally strong in ungrazed controls. Thus, changes were mainly attributed to differences in precipitation between years as opposed to grazing, as no significant effects thereof were detected. This was also confirmed by data on above-ground standing biomass. This changed tremendously over the years, with differences between various grazing regimes (factorial combination of grazing by livestock and small mammals) being smaller than interannual changes.
The results support the idea that on a local scale desert steppes experience non-equilibrium dynamics with water availability being far more important than livestock impact. As a result, it can be presumed that the danger of anthropo-zoogenic degradation is small. However, a nomadic way of life appears to be a crucial precondition for sustainable land use of these environments, thus, further aspects than precipitation data alone need to be taken into account when assessing the dynamics of the ecosystem
Is Degradation a Major Problem in Semi-Desert Environments of the Gobi Region in Southern Mongolia?
This paper tests predictions derived from the non-equilibrium theory of rangeland science. Data were collected in livestock enclosures situated in the relatively moist desert steppes of the Gobi Gurvan Saykhan region of southern Mongolia from 2000 to 2003. Plant community composition and species’ richness in enclosures showed clear differences between years, but these were equally strong in ungrazed controls. Thus, changes were mainly attributed to differences in precipitation between years as opposed to grazing, as no significant effects thereof were detected. This was also confirmed by data on above-ground standing biomass. This changed tremendously over the years, with differences between various grazing regimes (factorial combination of grazing by livestock and small mammals) being smaller than interannual changes.
The results support the idea that on a local scale desert steppes experience non-equilibrium dynamics with water availability being far more important than livestock impact. As a result, it can be presumed that the danger of anthropo-zoogenic degradation is small. However, a nomadic way of life appears to be a crucial precondition for sustainable land use of these environments, thus, further aspects than precipitation data alone need to be taken into account when assessing the dynamics of the ecosystem
Mapping Khulan Habitats: A GIS-Based Approach
This paper focuses on the contribution that a combination of public domain GIS data with extensive habitat data can make to Khulan conservation in southern Mongolia. We describe a dataset taken in the Great Gobi \u27A\u27 Strictly Protected Area which represents the driest region within the overall Khulan distribution range. Potential habitats were classified following a phyto-sociological approach based on vegetation samples collected in the field. These data are combined with an open source climate model that allowed assessment of the influences of mean precipitation and temperature regime on habitat conditions. The results are put into a Gobi-wide context providing an overview of an ongoing comprehensive habitat analysis of all main Khulan habitats in southern Mongolia
Preface
Preface to Erforschung biologischer Ressourcen der Mongolei, band 9, 2005.
First paragraph:
The present volume 9 of ”Biologische Ressourcen der Mongolei” continues the cooperation between the National University of Mongolia, Ulaan Baatar, and German academic institutions, mainly led by the University of Halle-Wittenberg. Thus, the volume stands in a tradition stretching now over 40 years (described in the respective chapter written by Stubbe et al.), but also raises new issues and topics. The chapters provided by Ts. Jamsran, W. Hilbig, E. Jäger, M. Stubbe und A. Stubbe demonstrate nicely that this cooperation is not only based on continued institutional but also on personal commitment, as these scientists had been working together long before political changes in the early 1990s and have carried out joint projects ever since. Contributions provided by young authors originate mainly from work recently done in the Mongolian-German Research Station in the Gobi Gurvan Saykhan region
Preface
Preface to Erforschung biologischer Ressourcen der Mongolei, band 9, 2005.
First paragraph:
The present volume 9 of ”Biologische Ressourcen der Mongolei” continues the cooperation between the National University of Mongolia, Ulaan Baatar, and German academic institutions, mainly led by the University of Halle-Wittenberg. Thus, the volume stands in a tradition stretching now over 40 years (described in the respective chapter written by Stubbe et al.), but also raises new issues and topics. The chapters provided by Ts. Jamsran, W. Hilbig, E. Jäger, M. Stubbe und A. Stubbe demonstrate nicely that this cooperation is not only based on continued institutional but also on personal commitment, as these scientists had been working together long before political changes in the early 1990s and have carried out joint projects ever since. Contributions provided by young authors originate mainly from work recently done in the Mongolian-German Research Station in the Gobi Gurvan Saykhan region
Non-native populations of an invasive tree outperform their native conspecifics
Introduced plants often face new environmental conditions in their non-native ranges. To become invasive, they need to overcome several biotic and abiotic filters that may trigger adaptive changes in life-history traits, like postgermination processes. Such early life cycle traits may play a crucial role in the colonization and establishment success of invasive plants. As a previous study revealed that seeds of non-native populations of the woody Siberian elm, Ulmus pumila, germinated faster than those of native populations, we expected growth performance of seedlings to mirror this finding. Here, we conducted a common garden greenhouse experiment using different temperature and watering treatments to compare the biomass production of U. pumila seedlings derived from 7 native and 13 populations from two non-native ranges. Our results showed that under all treatments, non-native populations were characterized by higher biomass production and enhanced resource allocation to aboveground biomass compared to the native populations. The observed enhanced growth performance of non-native populations might be one of the contributing factors for the invasion success of U. pumila due to competitive advantages during the colonization of new sites.Fil: Hirsch, Heidi. Stellenbosch University, Centre for Invasion Biology, Department of Botany and Zoology; Sudáfrica. Martin Luther University Halle-Wittenberg, Institute of Biology/Geobotany and Botanical Garden ; AlemaniaFil: Hensen, Isabell. Martin Luther University Halle-Wittenberg, Institute of Biology/Geobotany and Botanical Garden ; Alemania. German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig; AlemaniaFil: Wesche, Karsten. German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig; Alemania. Senckenberg Museum of Natural History Goerlitz; AlemaniaFil: Renison, Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones Biológicas y Tecnológicas. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Instituto de Investigaciones Biológicas y Tecnológicas; ArgentinaFil: Wypior, Catherina. Martin Luther University Halle-Wittenberg, Institute of Biology/Geobotany and Botanical Garden ; AlemaniaFil: Hartmann, Matthias. Charles University in Prague, Herbarium PRC & Department of Botany; República ChecaFil: von Wehrden, Henrik. Leuphana University, Institute of Ecology/Faculty of Sustainability, Centre of Methods; Alemania. Research Institute of Wildlife Ecology; Austri
Biparental inbreeding depression, genetic relatedness and progeny vigor in a wind-pollinated treeline species in Argentina
Spatially restricted gene flow and resulting spatial genetic structure are generally considered as being the primary controlling factors in the dynamics of biparental inbreeding depression in a wide range of plant species. However, wind-pollinated angiosperm trees have not been adequately studied in this respect. The present study analyses the relationships between parental genetic similarity, outcrossing distances and progeny vigour in Polylepis australis (Rosaceae), a wind-pollinated treeline species endemic to Argentina. We investigated whether spatial genetic structuring occurs in anthropogenically fragmented P. australis woodlands of the Córdoba Mountains. We also performed a controlled crossing experiment using pollen collected from different distances. Genetic variability (using RAPD-PCR) and vigour (survival and N metabolism capacity) of the resulting progeny were contrasted with progeny from unmanipulated flowers. We found a continuous decrease in parental genetic similarity with spatial distance among mates and an increase in genetic variability, survival and N metabolism capacity in the progeny produced from pollen at increasing distances. However, our further results suggest fragment connectivity in P. australis through effective long-distance pollen-mediated gene flow with no effective inbreeding depression problems observed under present day conditions.Fil: Seltmann, Peggy. Martin-Luther-University Halle-Wittenberg; AlemaniaFil: Hensen, Isabell. Martin-Luther-University Halle-Wittenberg; AlemaniaFil: Renison, Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones Biológicas y Tecnológicas. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Instituto de Investigaciones Biológicas y Tecnológicas; ArgentinaFil: Wesche, Karsten. University of Göttingen; AlemaniaFil: Ploch, Sebastián. University of Hohenheim; AlemaniaFil: Rondan Dueñas, Juan. Universidad Nacional de Córdoba; ArgentinaFil: Cocucci, Andrea Aristides. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; ArgentinaFil: Jung, Klaus. Helmholtz Centre for Environmental Research-UFZ; Alemani
Insektengerechte Landnutzung in Sachsen: Herausforderungen und Handlungsansätze
Der vorliegende Bericht stellt Ursachen für die Veränderungen der Insektenfauna zusammen. Daraus werden Vorschläge für Maßnahmen in Sachsen abgeleitet und diese inhaltlich sowie räumlich priorisiert. Die Autoren schaffen mit dem Bericht wissenschaftliche Grundlagen und geben Empfehlungen zur weiteren Umsetzung des sächsischen Handlungskonzepts ´Insektenvielfalt. Der Bericht richtet sich an alle Akteure des Naturschutzes und der Landbewirtschaftung.
Redaktionsschluss: 20.12.202
Tracking the origin of invasive Rosa rubiginosa populations in Argentina
The exact geographic origin of invasive species populations is rarely known; however, such knowledge is vital to understanding species’ invasion success, spread, and evolution as well as for assessing any biological control options. We investigated the shrub Rosa rubiginosa L., focusing on the presumed European origin of invasive populations in Argentina. We analyzed eight polymorphic microsatellite loci among 102 native (European) and 29 invasive (mainly central Argentinean and Patagonian) populations. Genetic diversity in the invasive range was clearly lower than in the native range, possibly because of a low number of introductions. Contrary to earlier hypotheses, the interpretation of principal coordinate analysis results and Jaccard dissimilarities contradicts the idea of the Argentinean populations having a Spanish origin. Instead, we found a close similarity between Argentinean samples and those from Germany, the Czech Republic, and Austria. We therefore assume that these neighboring countries are the most probable source regions for the Argentinean populations, which in some cases may also have arrived via Chile. According to historic information, emigrants from these regions may have introduced R. rubiginosa to South America in the nineteenth century on at least two occasions, either for food or as rootstock material for propagating living fences.Fil: Hirsch, Heidi. Martin-Luther-University Halle-Wittenberg; AlemaniaFil: Zimmermann, Heike. Martin-Luther-University Halle-Wittenberg; AlemaniaFil: Ritz, Christiane M.. Senckenberg Museum of Natural History Goerlitz; AlemaniaFil: Wissemann, Volker. Justus-Liebig-University Giessen; AlemaniaFil: von Wehrden, Henrik. Martin-Luther-University Halle-Wittenberg; Alemania. Leuphana University, Institute of Ecology and Environmental Chemistry; AlemaniaFil: Renison, Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones Biológicas y Tecnológicas. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Instituto de Investigaciones Biológicas y Tecnológicas; ArgentinaFil: Wesche, Karsten. Senckenberg Museum of Natural History Goerlitz; AlemaniaFil: Welk, Erik. Martin-Luther-University Halle-Wittenberg; AlemaniaFil: Hensen, Isabell. Martin-Luther-University Halle-Wittenberg; Alemani
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