Forty years of vegetation change in the desert grasslands of Big Bend National Park
Muldavin EH, Wondzell SM, Ludwig JA. 1997. Forty years of vegetation change in the desert grasslands of Big Bend National Park. Bulletin of the Ecological Society of America. 78(4):288
The Ecological Survey of the Big Bend Area established 77 transects in the desert grasslands of Big Bend National Park in 1955 to monitor long-term vegetation change. These transects were re-read by B. Warnock in 1960-1961 and in 1967, and again in 1981 by Wondzell and Ludwig. Were-read the transects in September of 1996, 40 years after they were first established. These permanent-plot studies are unique, providing the longest record of grass and shrub dynamics in existence for the desert grassland region. Our preliminary analysis indicates that these grasslands are highly dynamic, not only with respect to overall cover, but also in the turnover of individual plants. For example, Agave lechequilla density and cover declined significantly, while Bouteloua brevista increased on several sites. In other cases, cover remained more or less constant, but there was significant turnover of individuals. Some shallow soil sites have shown little or no change. But on deeper, loamy soils, there is a continuing trend of recovery of grasses. Our results suggest that under favorable climatic conditions, recovery of desertified grasslands is possible and more significant than previously thought.
- Type
- Journal Article
- Authors
- Muldavin, Esteban; Wondzell, Steven; Ludwig, John
- Units
- BIBE
- Keywords
- Change, desert grassland, Ecology, IAR, Plant Studies, Vegetation