Invasive Species Compendium

Detailed coverage of invasive species threatening livelihoods and the environment worldwide

Abstract

Native biodiversity increases with rising plant invasions in temperate, freshwater wetlands.

Abstract

Plant invasions change the landscape in unprecedented ways, influencing not only local wetland native biodiversity but also the regional homogenization of plant communities. Freshwater wetlands are particularly vulnerable to invasive plant impacts, but few studies provide a longitudinal assessment encompassing native biodiversity, plant invasions, and anthropogenic disturbance. We investigate the effects of invasive plant richness and abundance on wetland native biodiversity in 16 temperate, freshwater wetlands in central Pennsylvania. We calculate several commonly used plant community structure and wetland condition indices by site and sampling period across a 20-year timeframe. Results indicate that environmental stimuli had a significant impact on invasive plant abundance through time. Native plant richness and abundance was influenced more by shrub richness, non-native plant cover, and environmental stressors than by invasive plant dominance. This relationship was made evident by the high rate of dominant species turnover and prevalence of dominant native species. If an invasive plant dominated a wetland site, it was replaced by a different dominant native and/or invasive plant in 10 to 15 years, a key finding that relates to the replacement rate of dominant species in the herbaceous layer. This discovery suggests that under certain conditions, invasive plants may provide the necessary means by which a system can recover from a disturbance, which historically goes against the current dogma in the scientific community. Moreover, this supports the idea that some invasive plants serve as a type of secondary pioneer species of succession, aiding in the development of a more stable and biodiverse system over time.