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Home / Invasive Species Resources by Subject / Environmental and Ecological Impacts

Environmental and Ecological Impacts

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Invasive species can impact both the native species living within an ecosystem as well as the ecosystem itself.

Native species populations can be directly affected through predation, herbivory, and disease (Simberloff 2013). For example, the brown tree snake (Boiga irregularis) caused the extirpation of nine species of bird on Guam, and the hemlock woolly adelgid (Adelges tsugae) has caused widespread mortality of eastern hemlock trees by feeding on its sap (Simerloff and Rejmánek 2011).

Indirectly, invasive species may cause native species declines due to resource competition and habitat alteration (Davis 2009). For instance, plant invasions have been demonstrated to alter carbon and nitrogen cycles and fire regimes in invaded ecosystems (Simerloff and Rejmánek 2011). The invasion of downy brome (Bromus tectorum) in Western U.S. grasslands has led to an increase in the frequency and intensity of wildfires (Simerloff and Rejmánek 2011), and saltcedar (Tamarix spp.) makes the soil inhospitable to native species by depositing large amounts of salt into the surrounding soil (Bell et al. 2002).

See also: General Invasive Species Impacts

Citations

  • Bell, C.E., B. Neill, J.M. DiTomaso, et al. 2002. Saltcedar: a non-native invasive plant in the Western U.S. (PDF | 505 KB) University of California, Weed Research & Information Center. WRIC Leaflet #02-2.
  • Davis, M.A. 2009. “Impacts of invasions.” In: Invasion Biology. Oxford: Oxford University Press.
  • Simberloff, D., and M. Rejmánek, eds. 2011. Encyclopedia of Biological Invasions. Berkeley, Calif.: University of California Press.
  • Simberloff, D. 2013. Invasive Species: What Everyone Needs to Know. New York: Oxford University Press.

Spotlights

International Union for the Conservation of Nature.

IUCN has launched a global standard for classifying the severity and type of impacts caused by alien species, known as the Environmental Impact Classification for Alien Taxa (EICAT). This tool will alert scientists, conservation practitioners and policy makers to the potential consequences of invasive alien species, guiding the development of prevention and mitigation measures.

DOC. National Oceanic and Atmospheric Administration.

New research by NOAA and partners finds that two species of invasive Asian carp -- the bighead carp and silver carp, collectively known as bigheaded carps -- could be capable of establishing populations in Saginaw Bay, Lake Huron and affecting the health of ecologically and economically important fish species such as yellow perch. The research, appearing online in the journal Biological Invasions, is based on a new model that simulates interactions between the bigheaded carps and a range of fish species, including walleye, yellow perch, and groups lower on the food web over a time period of 50 years. Over 180 non-indigenous aquatic species have already become established in the Great Lakes, with a handful of these producing substantial negative impacts. While bigheaded carps are established in watersheds near the Great Lakes, they have not yet become established in the Great Lakes.

UNFAO. International Plant Protection Convention.
You cannot protect the environment without also safeguarding plant health. When plant pests and diseases spread into new areas they seriously damage entire ecosystems, putting at risk biological diversity and the environment itself. Tiny and lethal at the same time, plant pests and invasive alien species have been recently identified as the main driver of biodiversity loss. Pests are also responsible for losses of up to USD 220 billion in agricultural trade each year and the loss of 40 percent of the global food crop production. Climate change is making the situation even worse. It is changing the life cycle of pests – sometimes increasing the number of yearly generations - and creating new niches where they can thrive. For more information see the IPPC factsheet "Plant Health and Environmental Protection (PDF | 1.22 MB)".

USDA. FS. Northern Research Station.

In addition to cleaning the air and water, forests hold a tremendous amount of sequestered carbon. When trees die and then decay on the forest floor, that carbon is released into the atmosphere, a phenomenon that is one of the drivers of climate change. A first-of-its-kind study by a team that included the United States Department of Agriculture’s Forest Service and Purdue University scientists finds that non-native invasive insects and diseases are reducing the amount of carbon stored in trees across the United States. The study, “Biomass losses resulting from insect and disease invasions in USA forests,” is available at: https://www.nrs.fs.fed.us/pubs/58371.

Centre for Invasive Species Solutions (Australia).
A desire to avoid more extinctions is one of the drivers behind new research by the Threatened Species Recovery Hub which has identified invasive species as the no. 1 threat to Australian biodiversity with habitat loss a close second.

Selected Resources

The section below contains highly relevant resources for this subject, organized by source. Or, to display all related content view all resources for Environmental and Ecological Impacts

Partnership
Federal Government

DOI. NPS. Point Reyes National Seashore.

State and Local Government
City of Portland (Oregon). Environmental Services.
Professional
Proceedings of the National Academy of Sciences.
Doherty, T.S., A.S. Glen, D.G. Nimmo, E.G. Ritchie, and C.R. Dickman. 2016. Invasive predators and global biodiversity loss. Proceedings of the National Academy of Sciences 113(40):11261-11265.

California Native Plant Society.

In Fremontia, the journal of the California Native Plant Society.

Invasive Species Centre (Ontario).

Protecting ecosystems from degradation caused by invasive species can help protect species at risk and critical habitats. In 2019, the United Nations reported invasive alien species as a top-5 driver of species decline.

Invasive Species Centre (Ontario).

Protecting ecosystems from degradation caused by invasive species can help protect species at risk and critical habitats. In 2019, the United Nations reported invasive alien species as a top-5 driver of species decline.

Commercial
National Geographic Society.
Nile perch were introduced to Lake Victoria in the 1950s to boost the fishing industry. The introduction of Nile perch caused an economic boom, but almost caused cichlids, a native fish, to go extinct. Discover the role an invasive species can play in an ecosystem and social system.