Effects of Native Lupines on Ecosystem Functioning

Native perennial bunchgrass are important keystone species for reestablishment of native grassland communities. However, restoring native perennial bunchgrasses in California’s non-native annual grassland has been notoriously difficult. Previous work in the lab examined the effects of planting native legumes as possible “restoration facilitators” to promote growth plantings of a native bunchgrass, Stipa pulchra. Potthoff et al. (2009) found that Lupinus bicolor resulted in higher soil microbial biomass carbon and had distinct effects on soil microbial communities up to 28 months after planting. While some N from the lupins was taken up by the bunchgrass, this did not result in changes in biomass.

Current studies are examining the role of another species, Lupinus densiflorus, on native, relict stands of S. pulchra. Preliminary results suggest that L. densiflorus can cause rapid changes in bacterial and fungal amino sugars, followed by changes in nematode communities, with little effects on total soil N.

Amanda Hodson is conducting this research.

Potthoff, M., L.E. Jackson, S. Sokolow, and R.G. Joergensen. 2009. Responses of plants and microbial communities to litter addition and annual lupines in perennial California grassland restored with the bunchgrass, Nassella pulchra. Applied Soil Ecology 42:124-133. Potthoff et al., 2009

Jackson, L.E., M. Potthoff, K.L. Steenwerth, A.T. O’Geen, M.R. Stromberg, and K.M. Scow. 2007. Soil biology and carbon sequestration. Chapter 7. In: Ecology and Management of California Grasslands (Corbin, J., C. D’Antonio, and M.R. Stromberg, eds.). University of California Press, Berkeley, CA. pp. 107-118.

Pothoff, M., K.L. Steenwerth, L.E. Jackson, R.E. Drenovsky, K.M. Scow, R.G. Joergensen, 2006. Soil microbial community composition as affected by restoration practices in California grassland. Soil Biology and Biochemistry 38:1851-1860.  Potthoff et al 2006

Pothoff, M., L.E. Jackson, K.L. Steenwerth, I.Ramirez, M.R. Stromberg, and D.E. Rolston, 2005. Soil biological and chemical properties in restored perennial grasslands in California. Restoration Ecology 13:61-73. Potthoff et al 2005