Invasion of natural and agricultural cranberry bogs by introduced and native plants

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• 作者：Hilary A. Sandler ; Peter Alpert and Daniel Shumaker
• 关键词：Edge effect ; Introduced species ; New England ; Soil nutrients ; Vaccinium macrocarpon
• 刊名：Plant Ecology
• 出版年：2007
• 出版时间：June, 2007
• 年：2007
• 卷：190
• 期：2
• 页码：219-231
• 全文大小：253 KB

文摘

Plant species invasions, i.e., the entry of additional plant species into a habitat with negative effects on species already there, are a major ecological problem in natural habitats and a major economic problem in agricultural habitats. Nutrient availability, disturbance, and proximity to other habitats are likely factors that may interact to control invasion in both types of habitat. We hypothesized (1) that elevated nutrient availability can promote the abundance of introduced species even when high cover of the existing plant community is maintained, and (2) that higher levels of invasion on the edges than in the interiors of habitats are due to differences in resource availability between edges and interiors. To test these hypotheses, we measured soil characteristics and the abundances of plant species in natural and agricultural cranberry (Vaccinium macrocarpon Ait.) bogs in southeastern Massachusetts. Contrary to the first hypothesis, agricultural bogs did not have higher cover or richness of introduced species than natural bogs, despite having higher levels of soil nutrients. Contrary to the second hypothesis, the edges of both agricultural and natural bogs had a higher cover and richness of introduced species than the interiors, even though only natural bogs showed differences in resource availabilities between edges and interiors. Results suggest that having a high cover of existing species can counter positive effects of elevated nutrients on the spread of introduced and non-crop species. However, maintaining similar resource availabilities on the edges and interiors of habitats may not prevent greater invasion of edges. Avoiding disturbances to natural communities, maintaining high crop cover, and focusing active control of introduced or non-crop species on the edges of habitats could help limit plant invasions into natural and agricultural habitats alike.