Vegetation of a 25-Year Exclosure on the Edwards Plateau, Texas

Abstract

Communit.v composition wus variuhle and most species responded individual1.y to soil vuriables, partrcularly soil depth and degree and kind of stoniness. Common curl}Jmesquite (Hilaria belangeri) was the most characteristic and widespreud species of the area. Communities dominuted by Texas cupgruss (Eriochloa sericea), on soils greater than 2.5 cm in depth, produced 4

Axillary bud banks of two semiarid perennial grasses: occurrence, longevity, and contribution to population persistence

“…The station is located in the southwestern portion of the Edwards Plateau Land Resource Area at an elevation of 735 m. The climate is classi®ed as sub-tropical and semiarid (Smeins et al 1976;Smeins and Merrill 1988). Mean temperature is highest in July (30°C) and lowest in January (9°C).…”

“…The area is potentially a midgrass dominated grassland with scattered individuals or clumps of woody plants including, Quercus virginiana, Q. pungens var. vaseyena, Juniperus ashei and J. pinchotii (Smeins et al 1976;Smeins and Merrill 1988). However, intensive, long-term grazing by domestic herbivores has altered species composition by reducing the abundance of late-seral midgrasses, including B. curtipendula, and increasing the abundance of mid-seral shortgrasses, including H. belangeri, and several shrub species.…”

“…However, intensive, long-term grazing by domestic herbivores has altered species composition by reducing the abundance of late-seral midgrasses, including B. curtipendula, and increasing the abundance of mid-seral shortgrasses, including H. belangeri, and several shrub species. The abundance of late-seral midgrasses, including B. curtipendula, has increased following long-term (50 years) protection from domestic herbivores (Smeins et al 1976;Smeins and Merrill 1988). This investigation was conducted in two communities with contrasting grazing histories.…”

“…The two communities were approximately 2.5 km apart and speci®c study sites were located on similar soils with comparable topography. The long-term grazed community has a smaller proportion of late-seral grasses, including B. curtipendula and Eriochloa sericea, and a greater proportion of mid-seral shortgrasses, including H. belangeri, Bouteloua tri®da, and Erioneuron pilosum, compared to the ungrazed community (Smeins et al 1976;Smeins and Merrill 1988) Procedures Approximately 150 B. curtipendula and 150 H. belangeri tillers with in¯orescences were located on individual plants and permanently marked with wire loops along transects in the intensively grazed and ungrazed communities. Reproductive tillers were selected to ensure that axillary bud dierentiation and maturation had ceased by the time of marking.…”

The use of δ13C values of leporid teeth as indicators of past vegetation

“…This is expected because MAP has been shown to correlate with tree cover in subtropical and tropical grasslands and savannas (Sankaran, 2005;Bond, 2008). Because trees are C 3 photosynthesizers (Sage et al, 2011), and the vast majority of grasses on the Edwards Plateau are C 4 plants (Smeins et al, 1976;Fowler and Dunlap 1986), changes in the proportion of tree cover on the landscape will manifest itself as changes in the proportion of C 3 /C 4 plants and the biomass-weighted mean  13 C value of the vegetation. To better understand these processes, and to provide a framework for interpreting leporid tooth population data, we developed a Monte-Carlo model for simulating the production of teeth from a synthetic population of leporids living on the Edwards Plateau with the modern seasonal cycle of vegetation.…”