Co-invasion of similar invaders results in analogous ecological impact niches and no synergies

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• 作者：Daniel R. Tekiela ; Jacob N. Barney
• 关键词：Biological invasions ; Co ; invasion ; Deciduous forest ; Impact ; Interaction ; Invasive species ; Japanese stiltgrass ; Wavyleaf basketgrass
• 刊名：Biological Invasions
• 出版年：2017
• 出版时间：January 2017
• 年：2017
• 卷：19
• 期：1
• 页码：147-159
• 全文大小：
• 刊物类别：Biomedical and Life Sciences
• 刊物主题：Ecology; Freshwater & Marine Ecology; Plant Sciences; Developmental Biology;
• 出版者：Springer International Publishing
• ISSN：1573-1464
• 卷排序：19

文摘

Exotic species can cause changes to their invaded ecosystems, which can be large and long lasting. Despite most landscapes being invaded by multiple exotic plant species, >90 % of impact studies only characterize the impacts of single species. Therefore, our knowledge of invasive plant impacts does not reflect the co-invaded nature of most landscapes, potentially ignoring complex interactions among exotic species. Our objective was to characterize potential invader synergies (positive interactions) on biotic and abiotic ecological parameters among the important forest invaders Japanese stiltgrass (Microstegium vimineum) and wavyleaf basketgrass (Oplismenus undulatifolius), which co-invade eastern US deciduous forests. To characterize synergies, we used a factorial selective removal study, as well as an observational study to further explore invader cover-impact relationships. Although both invaders can reduce native plant richness by 70 % individually or in combination, there were no impact synergies. Total cover of any combination of the two invaders had a negative quadratic effect on total, exotic, and native plant richness; i.e., all community metrics were greatest at intermediate levels of total invader cover and lowest at maximum invader cover. Native richness was more greatly affected than exotic richness by the co-invasion. Soil metrics had no clear trend in either study. Japanese stiltgrass and wavyleaf basketgrass appear to have overlapping impact niches—the number, magnitude, and direction of biotic and abiotic changes to the invaded ecosystem—that only vary in impact magnitude, not breadth. As a result of their overlapping impact niches and non-synergies in this co-invaded system, the addition of the recent invader wavyleaf basketgrass has not resulted in additional changes to the invaded forests. Future impact studies should focus on multiple species and identifying synergies, especially as they relate to invader cover, which informs ecological interactions and management prioritization.