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Full-Text Articles in Weed Science
Effects Of Competition On Resource Availability And Growth Of A California Bunchgrass, Andrew R. Dyer, Kevin J. Rice
Effects Of Competition On Resource Availability And Growth Of A California Bunchgrass, Andrew R. Dyer, Kevin J. Rice
Faculty Publications
In California, little is known about the sensitivity of native bunchgrasses to competition or to changes in resource availability. We investigated the effect of nonnative annual vegetation on resource availability and growth of a native bunchgrass, Nassella pulchra, in a pair of factorial field experiments that incorporated effects of both interspecific and intraspecific competition as well as variation in soil depth. Plots of differing target densities and neighborhoods were used to assess changes in aboveground (light) and belowground (water) resource availability over multiple seasons in two sites with differing soil depth. N. pulchra grown without interspecific competitors grew larger …
Intraspecific And Diffuse Competition: The Response Of Nassella Pulchra In A California Grassland, Andrew R. Dyer, Kevin J. Rice
Intraspecific And Diffuse Competition: The Response Of Nassella Pulchra In A California Grassland, Andrew R. Dyer, Kevin J. Rice
Faculty Publications
In inland California grasslands, the high densities of alien annual species have altered the growing environment for native perennial grasses. Using variable-density plots, we measured the influence of intraspecific competition (conspecifics only) and diffuse competition (mixed-composition neighborhoods that include conspecifics) on growth and survival of Nassella pulchra, purple needlegrass. We assessed the effects of intraspecific and diffuse competition in weeded plots and unweeded plots, respectively, across a density gradient of N. pulchra plants (16–356 plants/m2). We used summer fire and spring sheep grazing to reduce diffuse competition in unweeded plots. The potential effect of rooting volume on competitive interactions …