Community River Restoration: Invasive Plant Species Edition
During the winter season, our river restoration projects focus on two activities that improve water quality and habitats for biodiversity: invasive plant removal and native tree planting. Too often, riparian habitats (land along the edges of rivers, streams, lakes, and other water bodies; also known as riparian zones, buffers, or areas) are dominated by plant species whose presence negatively impacts the health of the ecosystem.
Why are invasive plant species detrimental? Native plants and animals have a long evolutionary history with one another; for every new “advantage” that has evolved, there has been time for at least one or a few other species to adapt to circumvent that advantage. Consequently, native plant species are able to exert a degree of control over one another (in terms of population size). Non-native plant species, because they do not share a long evolutionary history with native plant species, may present novel characteristics that thwart native plant species and the ecosystems of which they are a critical part.
Removing invasive plant species helps to prepare room for native plant species that will protect waterways from pollution and provide the appropriate habitat for biodiversity.
Invasive plant species, like privet and bush honeysuckle:
- displace native plants that are better at holding soil and stabilizing streambanks,
- out-compete native plants for necessary resources such as light, water, and soil nutrients,
- and decrease biodiversity by dominating an otherwise biodiverse ecosystem.
All of these problems have negative impacts for our waterways:
- Shallow-rooted invasive plant species increase streambank erosion resulting in sediment loading of waterways, a form of non-point source pollution that impacts water quality, recreational use, and species health.
- Decreased biodiversity negatively impacts the food chain because invasive plant species are NOT good food sources for insects or mammals.
- Less biodiverse ecosystems are less resilient to extreme weather events such as drought or flooding, which have increased due to climate change.
- Less biodiverse ecosystems dominated by invasive plant species inhibit the growth of much-needed canopy trees.