Document: BRU-3-40-49

An analysis of changes in landscape structure and vegetation between the years 1871 and 1897 in the Arbuckle Mountains, Murray County, Oklahoma, USA.

HOAGLAND, B.* and B.WATKINS

University of Oklahoma, Norman, OK 73019, USA ¹

Abstract:
The ecological consequences of woody vegetation encroachment into grasslands is of great interest in conservation and plant community research reasons. In order to evaluate these effects, it is important to establish a baseline for comparison. The Arbuckle Mountains of south-central Oklahoma is situated on the biogeographic boundary of the eastern deciduous forest and western grasslands. Woody plant encroachment has been of concern in this region, but no analysis of historic vegetation patterns and landscape structure exist. In this study, we analyzed historic data in order to understand landscape structure in south-central Oklahoma. This was accomplished by digitizing 1871 and 1897 General Land Office survey plat maps ArcInfo GIS. Coverages were generated for vegetation, agriculture, settlements, hydrology and roads. Landscape structure was analyzed using FRAGSTATS. In addition, vegetation composition and woody plant densities were calculated from distance data extracted from surveyor notes. The most significant factor in landscape change was a marked increase in size and number of agricultural patches between 1987-1871. The affect was a loss of grassland and woody vegetation and attendant increases in patchiness. In addition, there was a threefold increase in roads. Trees with the greatest density were various species of Quercus, particularly Quercus stellata. Density and age classes varied as well between 1871 and 1897. Therefore, changes in land-use must be considered when evaluating the rate and degree of woody encroachment.

Keywords: Vegetation change, landscape structure, historic vegetation, General Land Office surveys

This abstract is being presented at: 10:30 AM in session:
Poster Session #5: Landscape Ecology.