Response of floodplain understorey species to environmental gradients and tree invasion: a functional trait perspective

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• 作者：André Terwei ; Stefan Zerbe ; Inga Mölder ; Peter Annighöfer…
• 关键词：Floodplain forest ; Fourth ; corner analysis ; Functional groups ; Prunus serotina Ehrh. ; RLQ analysis ; Robinia pseudoacacia L. ; Woody invader
• 刊名：Biological Invasions
• 出版年：2016
• 出版时间：October 2016
• 年：2016
• 卷：18
• 期：10
• 页码：2951-2973
• 全文大小：1,238 KB
• 刊物类别：Biomedical and Life Sciences
• 刊物主题：Life Sciences
  Plant Sciences
  Ecology
  Hydrobiology
  Zoology
  Forestry
  
• 出版者：Springer Netherlands
• ISSN：1573-1464
• 卷排序：18

文摘

Plants are connected to habitats by functional traits which are filtered by environmental gradients. Since tree species composition in the forest canopy can influence ecosystem processes by changing resource availability, litter accumulation, and soil nutrient content, we hypothesised that non-native invasive trees can establish new environmental filters on the understorey communities. In the hardwood floodplain forests in Northern Italy, the invasive trees Robinia pseudoacacia L. and Prunus serotina Ehrh. are the dominant canopy species. We used trait data assembled from databases and iterative RLQ analysis to identify a parsimonious set of functional traits responding to environmental variables (soil, light availability, disturbance, and stand structure) and the dominant native and invasive canopy species. Then, RLQ and fourth-corner analysis was conducted to investigate the joint structure between macro-environmental variables and species traits and functional groups were identified. The trait composition of the herb-layer was significantly related to the main environmental gradients and the presence of the invaders in the canopy showed significant relationships with several traits. In particular, the presence of P. serotina may mitigate or even erase the effect of disturbances, maintaining a stable forest microclimate and thus favouring ‘true’ forest species, while R. pseudoacacia may slow down forest succession and regeneration by establishing new stable associations with a graminoid-dominated understorey. The impact of the two invasive trees on herb layer composition appears to differ, indicating that different management and control strategies may be needed.