Environmental and Ecological Impacts

Nonnative tree species are gaining a foothold in forest ecosystems. These trees compete with native species for resources, sunlight, and space. Tree of heaven and Chinese tallow tree are the most invasive tree species in the South, according to a recent study which uses Forest Inventory & Analysis data to create an indicator of nonnative tree regeneration success and can help prioritize the species and locations for treatment. 

Garlic mustard (Alliaria petiolate) is a highly destructive invader in North America. As well as hindering the survival of native plants, it poses a particular threat to the survival of the rare West Virginia white butterfly (Pieris virginiensis).

A new scientific report, Summary for Policymakers of the Thematic Assessment Report on Invasive Alien Species and their Control of the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services, offers the most exhaustive look yet at how nonnative plants and animals can drive extinctions, disrupt food systems and harm human health. The report was compiled by 86 experts from 49 countries, who drew on thousands of scientific studies and contributions from Indigenous people and local communities. Key points:

• Invasive Alien Species Pose Major Global Threats to Nature, Economies, Food Security and Human Health
• Key Role in 60% of Global Plant & Animal Extinctions
• Annual Costs Now >$423 Billion – Have Quadrupled Every Decade Since 1970
• Report Provides Evidence, Tools & Options to Help Governments Achieve Ambitious New Global Goal on Invasive Alien Species

Native species in California's estuaries are expected to experience greater declines as invasive species interact with climate change, according to a study from the University of California, Davis. The study "Biological Invasions Alter Consumer-stress Relationships Along an Estuarine Gradient," published in the Ecological Society of America's journal, Ecology, said these declines are expected not only because of climate-related stressors, but also because of the expanding influence of new invasive predators whose impacts are occurring much farther up the estuary.

Over recent decades, globalization has led to an increase in the international flow of people and goods, bringing people together but also bringing together species that have never coexisted before. Species that are introduced and successfully colonize areas outside their natural ranges are considered ‘invasive’ and can have devastating impacts on species native to the region. Invasive species can cause the decline or extinction of native species, outcompeting them for food, water and space, preying upon them or introducing them to new diseases.

The U.S. Fish and Wildlife Service announced a final rule to reclassify the northern long-eared bat as endangered under the Endangered Species Act (ESA). The bat, listed as threatened in 2015, now faces extinction due to the rangewide impacts of white-nose syndrome, a deadly disease affecting hibernating bats across North America. The rule takes effect on January 30, 2023.