Reactive and inconsistent practices strengthen invasive plants in the US
As summer unfolds, more than 500 species of invasive plants will be taking root in fields, lawns, and gardens across the US. As plants continue to move north driven by climate change, the number of invasives will only increase. Unfortunately, inconsistent regulations that vary from state to state means that invasive plants have an edge on our attempts to control them. However, new research from the University of Massachusetts Amherst recently published in the Journal of Applied Ecology suggests that we already have an answer in hand—communication.
"We know that invasive plants are causing both ecological and economic harm in the US," says Emily Fusco, one of the paper's lead authors and a postdoctoral research fellow in the department of environmental conservation at UMass. One of the best tools that invasive-species managers have are prohibited plant lists, which are compiled and maintained by state and county-level officials to prevent intentional introductions of known invasive and weedy plants. Unfortunately, a lack of overall coordination lends a patchwork quality to efforts to control invasive plants.
The study's authors found that states in the lower 48 have listed anywhere between zero invasive plants and 162. Even worse, contiguous states often regulate very different sets of species: on average, only 20% of the plants listed as invasive in one state will show up on their neighbors' lists. Finally, states are failing to get ahead of emerging invasive plants: 90% of the time states only list a plant as invasive once it has already become present in their state, making it more difficult to eradicate. "We're missing an opportunity to prevent invasions before the species are widespread," says Fusco. "These prohibited plant lists are one of the most useful tools we have for preventing plant invasions, but our work shows that states are not creating these lists in a proactive way."
Yet, there's a bright side to all this: "It's not that the states are doing a bad job," says Evelyn Beaury, the paper's other lead author and a graduate student in organismic and evolutionary biology at UMass. "We don't need to reinvent the wheel—we just need to have more conversations about what happens across state borders. We need to give managers the infrastructure and resources to work together."
In fact, such work is already happening at the Northeast RISCC Network. RISCC (Regional Invasive Species and Climate Change) is a coalition of invasive species managers from throughout the Northeast who work with researchers and each other to identify and respond to new threats posed by invasives in a changing climate. "State officials want to improve coordination and share resources across borders," says Bethany Bradley, senior author and professor of environmental conservation at UMass. Bradley is also one of the cofounders of RISCC and says that the invasive species managers she works with through the network "are thrilled to have more ways to exchange information."
"We have a real chance to get ahead of the climate change/invasive species curve," says Beaury. "We need to get more people on board and that begins with starting conversations that cross state borders."