Nitrogen-limitation and invasive sweetclover impacts vary between two Great Plains plant communities

Biological Invasions
By: , and 



Yellow sweetclover is an exotic herbaceous legume common in the Great Plains of the US. Although woody legumes have been shown to affect ecosystem processes through nitrogen (N) fixation (i.e., they can be considered "transformers" sensu Richardson et al. (2000)), the same has not been shown for short-lived herbaceous species. The objectives of this study were to (1) quantify the effects of yellow sweetclover on N mineralization and nitrification and (2) assess the effects of N fertilization on two plant communities, badlands sparse vegetation and western wheatgrass prairie. We used in situ (in wheatgrass prairie) and laboratory incubations (for both plant communities) to assess N dynamics at sites with high and low sweetclover cover in the two plant communities. We found that both N mineralization and nitrification were higher in the high sweetclover plots in the sparse plant community, but not in the wheatgrass prairie. To assess fertilization effects and determine if nutrients or water were limiting at our sites, we conducted a field experiment with five resource addition treatments, (1) N, (2) N + water, (3) water, (4) phosphorus, and (5) no addition. Water was limiting in the wheatgrass prairie but contrary to expectation, N was not. In contrast, N was limiting in the sparse community, where a fertilization effect was seen in exotic forbs, especially the toxic invader Halogeton glomeratus. Our results emphasize the contingent nature of plant invasion in which effects are largely dependent on attributes of the recipient vegetation.

Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Nitrogen-limitation and invasive sweetclover impacts vary between two Great Plains plant communities
Series title Biological Invasions
DOI 10.1007/s10530-009-9678-y
Volume 12
Issue 8
Year Published 2010
Language English
Publisher Springer
Publisher location Amsterdam, Netherlands
Contributing office(s) Northern Prairie Wildlife Research Center
Description 15 p.
Larger Work Type Article
Larger Work Subtype Journal Article
Larger Work Title Biological Invasions
First page 2735
Last page 2749
Country United States
Other Geospatial Great Plains
Google Analytic Metrics Metrics page