Abstract
The objectives of this study were to a) describe the present herbaceous cover at the Biological Experiment Section (BES), b) study association of vegetation and soil, c) identify tentative range sites, and d) evaluate vegetation trends having occurred during 16 years of protection from fire and livestock grazing. Surface soil samples, totaling 1,108, were subjected to textural analysis and classified according to color as red, brown and gray. Only 81 samples were not classified as sandy loam. Four vegetation types visually detected could not be related to soil texture. Therefore, to sample the herbaceous vegetation based on permanent soil features, 121 quadrats 0.5m² in size were proportionally allocated to red, brown and gray soil areas. For subsequent analysis these quadrats were also stratified into three elevation classes including 92 to 94 m, 94 to 97 m and 97 to 100 m above sea level. Plants inside each quadrat were individually measured, bagged, and dried at 70°C until constant weight. Soil depth to hardpan was determined using a probe. Least squares analyses of variance for density (D), basal area (BA) and standing crop (SC) of total vegetation indicated no significant differences occurred across soil color and elevation strata. Soil depth was an important factor with respect to variation in D, BA and SC of total vegetation and also individual vegetation groups. Analyses of simple and multiple correlation indicated a weak relationship between soil depth with elevation and percent sand, silt, and clay. None of the soil related factors including soil depth, were strongly correlated with D, BA or SC of total vegetation..
Frometa-Bello, Luis Vincente (1977). Analysis of the herbaceous vegetation in a Trachypogon savannah exclosure in the high Llanos near Calabozo, Venezuela. Texas A&M University. Texas A&M University. Libraries. Available electronically from
https : / /hdl .handle .net /1969 .1 /DISSERTATIONS -627300.