Ecological and agronomic consequences of Cicer milkvetch (Astragalus cicer L.) introduction into Mixed Prairie grassland

Dr. Cameron Carlyle | Assistant Professor
Department of Agricultural, Food & Nutritional Science
Faculty of Agricultural, Life & Environmental Sciences
University of Alberta

Cicer milkvetch is an introduced legume that is beginning to encroach on native mixed grass prairie plant communities within the Mattheis Research Ranch. By measuring soil properties, plant biomass, and plant community composition in areas with and without cicer milkvetch, Dr. Carlyle and undergraduate student Kyle Le assessed the localized effects of invasions by this species on rangeland ecosystem functions. They found that forage quantity and quality were highest in plots with cicer milkvetch, and that nitrogen content of grasses also increased in these plots. However, plant diversity was lowest in cicer milkvetch plots, and the species in question was associated with a decline in the biomass of grasses and other forbs. Soil carbon was not different between plot types, but there was a trend of cicer milkvetch plant size being negatively related to soil carbon. These data show that an invasive plant can have positive, neutral and negative impacts on different ecosystem goods and services. As these rangelands become increasing valued for goods and services other than forage production, land managers should begin monitoring and considering these other values.