Heike Zimmermann
Martin Luther University of Halle-Wittenberg
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Publication
Featured researches published by Heike Zimmermann.
International Journal of Plant Sciences | 2010
Heike Zimmermann; Christiane M. Ritz; Heidi Hirsch; Daniel Renison; Karsten Wesche; Isabell Hensen
Rosa rubiginosa (Rosaceae) populations introduced to Argentina successfully invade various habitats, forming extensive impenetrable thickets. To investigate the consequences of founder events and to track the native origin of Argentinean populations, the genetic diversity of invasive R. rubiginosa populations was compared with that of native populations in Europe, and genetic similarity was assessed between groups. We sampled 13 Argentinean populations and 20 native populations in Germany and Spain, and we applied two molecular marker techniques (simple sequence repeats and random amplification of polymorphic DNA [RAPD]). Genetic diversity within the invasive range was clearly lower than it was in the native range. Principle coordinate analysis and between‐class analysis did not reveal the exact European origin of the invasive populations, but our data suggest that at least one Argentinean population originated in Germany. Overall, the strong similarity of RAPD and allelic phenotypes throughout Argentina suggests a limited number of introduction events, that the species spread through human transport, and that the few genetic phenotypes present in the species were conserved largely unaltered as a result of mainly asexual reproduction.
International Journal of Plant Sciences | 2011
Heidi Hirsch; Heike Zimmermann; Christiane M. Ritz; Volker Wissemann; Henrik von Wehrden; Daniel Renison; Karsten Wesche; Erik Welk; Isabell Hensen
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.
F1000Research | 2014
Heike Zimmermann; Patric Brandt; Jörn Fischer; Erik Welk; Henrik von Wehrden
Research on biological invasions has increased rapidly over the past 30 years, generating numerous explanations of how species become invasive. While the mechanisms of invasive species establishment are well studied, the mechanisms driving abundance patterns (i.e. patterns of population density) remain poorly understood. Invasive species typically have higher abundances in their new environments than in their native ranges, and patterns of invasive species abundance differ between invaded regions. To explain differences in invasive species abundance, we propose the Human Release Hypothesis. In parallel to the established Enemy Release Hypothesis, this hypothesis states that the abundance of invasive species may be partly explained by the level of human activity or landscape maintenance, with intermediate levels of human activity providing optimal conditions for high abundance. The Human Release Hypothesis does not negate other important drivers of species invasions, but rather should be considered as a potentially important additional or complementary mechanism. We illustrate the hypothesis via a case study on an invasive rose species, and hypothesize which locations globally may be most likely to support high abundances of invasive species. We propose that more extensive empirical work on the Human Release Hypothesis could be useful to test its general applicability.
Agroforestry Systems | 2012
Regine Brandt; Heike Zimmermann; Isabell Hensen; Juan Carlos Mariscal Castro; Stephan Rist
Austral Ecology | 2011
Heike Zimmermann; Henrik von Wehrden; María Angélica Damascos; Donaldo Bran; Erik Welk; Daniel Renison; Isabell Hensen
Ecological Research | 2009
Heike Zimmermann; Daniel Renison; Ilona Leyer; Isabell Hensen
Folia Geobotanica | 2009
Henrik von Wehrden; Heike Zimmermann; Jan Hanspach; Katrin Ronnenberg; Karsten Wesche
Biological Invasions | 2012
Heike Zimmermann; Henrik von Wehrden; Daniel Renison; Karsten Wesche; Erik Welk; María Angélica Damascos; Isabell Hensen
Forest Ecology and Management | 2013
Maya Svriz; María Angélica Damascos; Heike Zimmermann; Isabell Hensen
NeoBiota | 2015
Heike Zimmermann; Jacqueline Loos; Henrik von Wehrden; Joern Fischer