Evolutionary, ecological and social consequences of Biological Invasions

1. GEOBOTANIK Düsseldorf Biological Invasions Impacts Biodiversity Ecosystem Function Society The invasive alien Epilobium ciliatum (American Willowherb) forms hybrids with seven native Epilobium species. Gene flow between alien and native plant species or genotypes may lead to an irreversible loss of native biodiversity (genetic resources). The aim of subproject 1 (University of Osnabrück) is to develop tools to distinguish between introduced and native plant biodiversity and to develop sustainable strategies to protect native genetic resources. native: I. noli-tangere end of 19th cent.: I. parviflora (from Central Asia) fifty years ago: I. glandulifera (from Northern India) 1994: I. capensis (from North America) 2004: I. balfourii (from Himalayas) bleeker@biologie.uni-osnabrueck.de Evolutionary, ecological and social consequences of Biological Invasions University of Osnabrück Department of Systematic Botany Heinrich-Heine-University Düsseldorf Department of Geobotany Invasive species are now viewed as a significant component of global change. Invasions of new territories follow accidental or deliberate introductions by man or are caused by climatic changes. The impacts of biological invaders can be tremendous. They may lead to changes of ecosystem function, threaten the indigenous flora and fauna, add to its species richness, cause epidemic diseases and become pest organisms. Negative consequences of biological invasions can only be avoided through precautionary measures. The aim of our multidisciplinary project is to develop sustainable strategies to prevent biological invasions (if possible) and to minimize their negative effects. One of the most important sources for neophytes are plants escaping from cultivation such as oilseed rape (Brassica napus L.). The aim of subproject 2 (University of Osnabrück) is to investigate the ability of oilseed rape to establish itself outside of rape fields and hybridise with close relatives such as B. rapa. When cultivating transgenic varieties, gene flow to ruderal or wild populations could result in a transfer of modified genes. Ambrosia artemisiifolia (Ragweed) is an invasive alien species (IAS) that represents a major health problem. The pollen of this wind pollinated plant is a strong allergen causing hay fewer. The aims of subproject 4 (UFZ) are to estimate the socioeconomic costs and to identify efficient measures to avoid damages. Other parts of the subproject are dealing with legal aspects of IAS and with selective aspects of governing IAS-problems in a more self regulating process. The genus Impatiens (touch-me-not) has increased five times the species number in Central Europe since appr. 120 years. This has affected ecosystem relations and caused niche shifts of co-existing taxa or their substitution. The aim of subproject 3 (H.-Heine-Univ. Düsseldorf) is to characterize the niches occupied by the invaders in the initial phases of their colonization. Potential negative effects are identified and measures can be taken to eliminate noxious aliens in the very beginnings of their regional spread. Sponsored by Contact: PD Dr. Walter Bleeker, University of Osnabrück bleeker@biologie.uni-osnabrueck.de