Effects of Genome Size and Legacy Shrub Removal on Plant Assemblages in the Sagebrush Steppe
Abstract
Sagebrush steppe ecosystems are widespread and support a wide variety of native plant and animal species. However, these ecosystems are being lost at an alarming rate due to the intentional removal of big sagebrush (Artemisia tridentate) and altered fire regimes due to invasive grasses. There is great interest in understanding how plant assemblages recover following these disturbances, and how organismal traits can be used to anticipate this recovery. Here, we are studying how the legacies of sagebrush removal affect plant recovery following wildfire, and the potential for genome size to be a key trait influencing recovery. Genome size refers to the total amount of genetic information (DNA) within a single complete genome, and it can vary greatly among plant species. Because genetic material is rich in nitrogen and phosphorus, larger genomes require more nitrogen and phosphorus than smaller genomes, which may affect plant resource competition. We anticipated that community-weighted mean (CWM) genome size would be larger in higher resource conditions, such as in shrub removal plots and shrub-engineered ‘fertile island’ microhabitats. We found that CWM genome size was greater in shrub removal plots, but not in shrub-engineered fertile islands. Data analyses of individual species are still ongoing to evaluate the drivers of this response.
Effects of Genome Size and Legacy Shrub Removal on Plant Assemblages in the Sagebrush Steppe
Sagebrush steppe ecosystems are widespread and support a wide variety of native plant and animal species. However, these ecosystems are being lost at an alarming rate due to the intentional removal of big sagebrush (Artemisia tridentate) and altered fire regimes due to invasive grasses. There is great interest in understanding how plant assemblages recover following these disturbances, and how organismal traits can be used to anticipate this recovery. Here, we are studying how the legacies of sagebrush removal affect plant recovery following wildfire, and the potential for genome size to be a key trait influencing recovery. Genome size refers to the total amount of genetic information (DNA) within a single complete genome, and it can vary greatly among plant species. Because genetic material is rich in nitrogen and phosphorus, larger genomes require more nitrogen and phosphorus than smaller genomes, which may affect plant resource competition. We anticipated that community-weighted mean (CWM) genome size would be larger in higher resource conditions, such as in shrub removal plots and shrub-engineered ‘fertile island’ microhabitats. We found that CWM genome size was greater in shrub removal plots, but not in shrub-engineered fertile islands. Data analyses of individual species are still ongoing to evaluate the drivers of this response.