Abstract Title
Understanding Effects of Genome Size and Legacies of Nitrogen Addition on Post-Fire Sagebrush Steppe Plant Assemblages
Abstract
Many sagebrush steppe ecosystems have been disturbed or lost due to human land use, plant invasions, and wildfire. In addition, humans have greatly enhanced biological nitrogen (N) availability, and atmospheric N deposition into steppe ecosystems which may exacerbate their decline. Nitrogen is a rate-limiting nutrient in these ecosystems, and N deposition can relieve this limitation, thereby causing long-lasting change in ecological communities. Organismal traits may be used to anticipate these changes, and genome size may be a particularly influential trait because genomic material has a high demand for N. Genome size measures the amount of genetic material in a complete genome and is highly variable among plant species, potentially affecting plant competition for N. Here, we studied the effects of plant genome size and legacies of simulated N deposition on post-fire sagebrush steppe plant assemblages, as well as potential effects of shrub-engineered ‘fertile island’ microhabitats. We measured community weighted mean genome size (CWM-GS) using public databases and plant cover surveys from a long-term N deposition study. We found no effect of legacy N addition on CWM-GS, nor an interaction effect between legacies of N addition and shrub fertile islands. However, CWM-GS was significantly lower in shrub fertile islands.
Understanding Effects of Genome Size and Legacies of Nitrogen Addition on Post-Fire Sagebrush Steppe Plant Assemblages
Many sagebrush steppe ecosystems have been disturbed or lost due to human land use, plant invasions, and wildfire. In addition, humans have greatly enhanced biological nitrogen (N) availability, and atmospheric N deposition into steppe ecosystems which may exacerbate their decline. Nitrogen is a rate-limiting nutrient in these ecosystems, and N deposition can relieve this limitation, thereby causing long-lasting change in ecological communities. Organismal traits may be used to anticipate these changes, and genome size may be a particularly influential trait because genomic material has a high demand for N. Genome size measures the amount of genetic material in a complete genome and is highly variable among plant species, potentially affecting plant competition for N. Here, we studied the effects of plant genome size and legacies of simulated N deposition on post-fire sagebrush steppe plant assemblages, as well as potential effects of shrub-engineered ‘fertile island’ microhabitats. We measured community weighted mean genome size (CWM-GS) using public databases and plant cover surveys from a long-term N deposition study. We found no effect of legacy N addition on CWM-GS, nor an interaction effect between legacies of N addition and shrub fertile islands. However, CWM-GS was significantly lower in shrub fertile islands.