Additional Funding Sources

This project was made possible by the NSF Idaho EPSCoR Program and by the National Science Foundation under Award No. OIA-1757324.

Abstract

Big sagebrush (Artemisia tridentata) stretches across the American west but is currently in danger from over-grazing, exotic species invasion, and climate change. Sagebrush plants serve as a home to hundreds of arthropod species, and the specific communities vary based environmental and biotic factors. Across ecosystems, arthropod richness tends to decrease as elevation increases, but factors within their sagebrush host also affect the composition of arthropod communities. Differing genomes between plants, resulting from hybridization events, as well as different ploidy levels manifest as chemical, physical and phenological differences between sagebrush individuals. The genetic variations in sagebrush form the basis of an extended phenotype for the community, in which larger community structure and ecosystem processes are affected by these heritable differences. This study explores the influence of elevation, genome, and ploidy level on arthropod community richness across sagebrush steppes at Big Lookout Mountain in Oregon and in Almo, ID at Castle Rocks State Park. Our study plots are home to three subspecies of big sagebrush: basin big sagebrush (Artemisia tridentata ssp. tridentata) and mountain big sagebrush (A. t. ssp. vaseyana) in Oregon and Wyoming big sagebrush (A. t. ssp. wyomingensis) and mountain at Castle Rocks with diploid and tetraploid hybrid zones lying between them. Using calculations of arthropod richness based on morphotype classification for each plot, I estimated which abiotic or biotic factor of big sagebrush most significantly impacts arthropod richness at our study sites. As sagebrush communities continue to be threatened by anthropogenic and climatological effects, understanding the implications of plant genetics and elevation on the larger steppe community will be integral to management decisions. This study also furthers our understanding of sagebrush steppes as a possible model ecosystem for the field of community genetics, connecting arthropod populations to heritable variations in big sagebrush and providing a foundation to explore interactions at higher trophic levels.

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Examining the Influence of Elevation and Genotype in Arthropod Communities of Artemesia tridentata

Big sagebrush (Artemisia tridentata) stretches across the American west but is currently in danger from over-grazing, exotic species invasion, and climate change. Sagebrush plants serve as a home to hundreds of arthropod species, and the specific communities vary based environmental and biotic factors. Across ecosystems, arthropod richness tends to decrease as elevation increases, but factors within their sagebrush host also affect the composition of arthropod communities. Differing genomes between plants, resulting from hybridization events, as well as different ploidy levels manifest as chemical, physical and phenological differences between sagebrush individuals. The genetic variations in sagebrush form the basis of an extended phenotype for the community, in which larger community structure and ecosystem processes are affected by these heritable differences. This study explores the influence of elevation, genome, and ploidy level on arthropod community richness across sagebrush steppes at Big Lookout Mountain in Oregon and in Almo, ID at Castle Rocks State Park. Our study plots are home to three subspecies of big sagebrush: basin big sagebrush (Artemisia tridentata ssp. tridentata) and mountain big sagebrush (A. t. ssp. vaseyana) in Oregon and Wyoming big sagebrush (A. t. ssp. wyomingensis) and mountain at Castle Rocks with diploid and tetraploid hybrid zones lying between them. Using calculations of arthropod richness based on morphotype classification for each plot, I estimated which abiotic or biotic factor of big sagebrush most significantly impacts arthropod richness at our study sites. As sagebrush communities continue to be threatened by anthropogenic and climatological effects, understanding the implications of plant genetics and elevation on the larger steppe community will be integral to management decisions. This study also furthers our understanding of sagebrush steppes as a possible model ecosystem for the field of community genetics, connecting arthropod populations to heritable variations in big sagebrush and providing a foundation to explore interactions at higher trophic levels.

 

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