Date of Award
Thesis open access
Globally, arid and semi-arid grassland ecosystems are being invaded by woody tree and shrub species. Over the past 200 years in the United States in central and western Texas and throughout the Southwest such an invasion has altered the landscape from dominant C4 perennial bunchgrass vegetation to closed canopy forests of mainly Juniperus spp. and Prosopis spp. There have been widespread campaigns to remove these woody species to increase grassland acreage and biodiversity for forage and as wildlife habitat. Nonetheless, removal efforts have been foiled due to the invasion by an exotic species introduced to improve rangelands. King Ranch Bluestem (a.k.a. KR bluestem, Bothriochloa ischaemum (L.) Keng var. songarica), is a highly invasive, non-native, C4, perennial grass. The invasive nature and competitive dynamics of this species are under investigation by many researchers because it threatens native biodiversity and rangeland and wildlife habitat health. My study is designed to assess change in herbaceous grassland communities following Juniperus ashei clearing on the eastern Edwards Plateau of Central Texas. I quantify differences in herbaceous cover and diversity in grassland ecosystems as a function of modes of J. ashei removal (chainsaw, bulldozer, or Cedar Eater), and post-removal land management (seeding with native grass mixtures and lopping of J. ashei seedlings.). The ultimate goal of the study is to provide landowners of Central Texas with practical information for how to improve grassland habitat quality for wildlife while preventing non-native species invasions. Results of the study suggest that removal of J. ashei with a chainsaw followed by periodic lopping of saplings is the most effective tool for grassland restoration.
Bradshaw, Cade C., "Effects of Mode of Cedar (Juniperus ashei) Removal on Grassland Species Composition in the Texas Hill Country" (2014). Biology Honors Theses. Paper 14.