What Drives Species Richness in Colorado's Alpine Tundra

• Main Author: Kintgen, Michael
• Other Authors: Catherine Kleier
• Format: Text
• Language: English
• Published: ePublications at Regis University 2018
• Subjects: Alpine; Tundra; Species Richness; Colorado; precipitation gradient; substrate pH; Plant community; Biology; Ecology and Evolutionary Biology; Other Ecology and Evolutionary Biology; Plant Biology; Patagonia
• Online Access: https://epublications.regis.edu/theses/851; https://epublications.regis.edu/context/theses/article/1865/viewcontent/Environmental_Biology_Masters_Project_Kintgen_Final.pdf

Despite years of research, drivers of vascular plant species richness in Colorado’s alpine tundra habitats are largely unknown. Factors such as slope aspect, Pleistocene glaciation, nutrient levels, latitude and longitude, snow depth, and disturbance have been studied. Despite this research, few patterns have emerged. Research in Colorado has been conducted on a few well studied mountains. Aridity is one factor that has not been well studied but shows promise in explaining species richness. In Patagonia and the Swiss Alps, increasing aridity correlates with higher species richness. Here, a full species assessment was conducted on nine mountains previously under researched or not researched in fell field and dry meadow communities. These nine sites covered the precipitation gradient in Colorado from driest to wettest conditions (425mm-1941mm) found above 3657 meters. We found that the abiotic factors of increased precipitation, substrate pH, rather than aridity offered a better explanation of what drives higher species richness. Additionally, we discuss an ecotone between fell fields and dry meadows that can form between these two communities or where topography creates intermediate communities with conditions and species composition shared by both communities. We define a new addition to alpine vegetation communities, pseudo-fell field. This community develops where environmental conditions are similar to true fell fields and include both traditional fell field species, but the overall species composition is unique to this community. If we are able to more accurately characterize in-situ community types, researchers will better understand Colorado’s alpine environments and how future changes will impact them.