Characteristics and Distribution of Arbutus xalapensis (Texas Madrone) in the Edwards Plateau Region of Central Texas

Little is known about Arbutus xalapensis and the characteristics of the community in which it inhabits. The aim of this study is to examine the ecological role of Arbutus xalapensis and further the understanding of the Edwards Plateau ecological region of Texas. A population of mature Arbutus xalapensis at the Albert and Bessie Kronkosky State Natural Area within Kendall and Bandera counties, Texas was assessed to determine various habitat and species-specific characteristics. Basal area, height, soil depth, density, and elevation parameters were used to examine the overall population in addition to comparing habitat type, geology, and disturbance. A total of 98 individual A. xalapensis were assessed within canyon, hillside, and upland communities and statistically significant differences were found for all collected parameters. Upland individuals were found to have the highest mean basal area (0.021 ± 0.019 m2) and height (4.09 ± 1.70 m), though they had the lowest density (2.23 ± 2.84 individuals/Ha), the deepest soil depth was found within the canyon community (27.15 ± 20.48 cm). The highest density was found within the hillside community (61.44 ± 38.03 individuals/Ha). Statistically significant differences were also found between Fort Terrett Member and Upper Glen Rose geologic formations. Fort Terrett Member individuals were found to be significantly larger in basal area (0.023 ± 0.022 m2) and significantly lower in density (2.09 ± 2.79 individuals/Ha). No significant differences were found between disturbed and undisturbed communities. These data will assist in better understanding of Arbutus xalapensis and the communities it occurs within, as well as the Edwards Plateau ecological region of Texas.