Vascular Plant Survey of the Canyonlands Unit of the Big Thicket National Preserve, Tyler County, Texas

Abstract

The Big Thicket National Preserve is located in the southern part of the United States. It is within the Pineywoods vegetation region of southeastern Texas. This study area was the Canyonlands Unit, a unit located entirely within Tyler County, Texas. This unit is one of the most recently acquired units within the Big Thicket National Preserve. It was acquired in 1993 and is composed of 1,476 acres.

The purpose of this study was to make a complete list of all the vascular plant species within the Canyonlands Unit. The numbers of plant species within this unit were compared to three other units within the preserve that are relatively close to the Canyonlands Unit. The plant species within these units were compared on number of species that are native versus introduced, longevity, season of growth, plant type (woody versus herbaceous), plant group (monocots, dicots, gymnosperms, ferns) and upland versus wetland plants based on region six wetland indictor values. The wetland plant species were compared among themselves as the number of obligate species versus facultative wetland plant numbers. This study also shows the number of invasive and weedy species within the Canyonlands Unit.

Along with determining the number of plant species and comparing those with the number of species in the other units, a Cluster Analysis and Indicator Species Analysis was conducted on the woody vegetation within the Canyonlands Unit in order to determine woody plant communities. These analyses were conducted by using the statistical software, PC-ORD.