Invasive plant species present serious environmental, economic and social problems worldwide. Their abundance can lead to lost native biodiversity and ecosystem functions such as nutrient cycling.
Despite substantial research, little is known about why some species dominate new habitats over native plants that should have the advantage.
A common but rarely tested assumption, say biologists, is that these plants are more abundant in introduced versus native communities because they behave in a special way.
Colorado State University faculty members Cynthia Brown, associate professor in the College of Agricultural Sciences, and Julia Klein, assistant professor in the Warner College of Natural Resources, are participants in the Nutrient Network (NutNet) with collaborator Dana Blumenthal from the U.S. Department of Agriculture-Agriculture Research Service (USDA-ARS). NutNet is a global collaboration of scientists that tested this “abundance assumption” for 26 plant species in 39 locations on four continents.
NutNet published its first paper recently in Ecology Letters, revealing that non-native plant species most often occur in similar abundances in their introduced areas as their home regions.
Brown, Klein and Blumenthal have established two NutNet study sites, one at the Shortgrass Steppe Long Term Ecological Research site near Nunn, Colo., and another at the USDA-ARS High Plains Grassland Research Station near Cheyenne, Wyo. These are two of more than 50 grassland study sites around the world in which the same experimental treatments are being applied.
“Experiments that are conducted across multiple sites worldwide are essential to answer key questions about biological invasions, which we, as a society, spend a lot of time and money managing. The findings will contribute to our ability to predict and prioritize plant invasions,” Brown said.
The Colorado and Wyoming NutNet sites not only contribute to this global research effort, but are useful field educational tools. Klein annually takes her undergraduate class, Ecosystems in a Changing World, to visit the experiments at the shortgrass steppe to see first-hand how different global changes are affecting the grasslands there. Graduate student Laura Dev and former graduate student Aaron Berdanier, both from the Graduate Degree Program in Ecology, have also learned about international, collaborative research by participating in the NutNet research program at CSU.
“Invasions are one of the pressures that ecosystems and societies are facing across the globe. Understanding how invasions interact with other large-scale drivers of change, such as nutrient additions and land-use change, will be the subject of our future publications,” Klein said.
Colorado State University has long been a leader in grasslands ecology, with scientists working locally in Colorado’s grasslands and globally from the great African savannas to the high plateau of Tibet. While Colorado State University scientists strive to conduct work that advances the field theoretically, their work also has practical implications for management and for sustaining these ecological systems, their services and the human communities that depend upon them.