Plant invasions linked to less stable plant communities from plots to ecosystems

How invasions change stability

Plant invasions were associated with lower stability from local plots to metacommunities, or networks of connected local communities. Locally, invasion-associated losses of functional diversity were linked to less asynchronous species dynamics, meaning species were less likely to compensate for one another when conditions changed. Shifts toward acquisitive growth strategies—traits associated with rapid resource use and growth—were linked to lower stability at the species level. Together, these changes reduced local stability.

At the metacommunity scale, invasion-associated shifts toward more acquisitive seed-dispersal strategies were linked to lower functional differences among local communities. That reduced spatial asynchrony, meaning connected communities fluctuated more similarly rather than offsetting one another. The combined decline in local stability and spatial asynchrony was associated with lower stability across the metacommunity.

Why scale matters

The findings indicate that the effects of plant invasions on stability may extend beyond individual plots. Managing invasions may therefore need to consider both the diversity of traits within local plant communities and the connections among separate communities, rather than focusing only on one location at a time.

Evidence and caveats

The study analyzed data from the National Ecological Observatory Network and used a multiscale framework linking plant invasion, functional traits and the stability of total community cover. The reported relationships are associations: the abstract does not establish that invasions alone caused every observed change. The provided material also does not specify the number of sites, the observation period or how representative the sampled communities are of all ecosystems. The study uses total community cover as a measure of total community abundance.