Abstract
Vegetation of the Blue Hills area of northern Newton County, Texas, was sampled in 51 forest stands representing the range of vegetation types of this region of the "upper" Big Thicket. Two managed and 16 natural forest types were recognized. Distinctive upland and streamside communities were separated by principal component analyses ordination. The ordination revealed two gradients, one each in uplands and streamsides reflecting four related environmental variables: soil series, topography, soil moisture, and successional status. Basal areas and densities of trees and saplings, and density of shrub stratum were significantly correlated with position along the first axis, with an evident decline in density and basal area from mesic to xeric sites. Diversity (H') values of the tree and shrub strata were comparable with those reported from other coastal plains forests. Alpha diversity increased from xeric to mesic habitats and was correlated with stand position along axis 1. Successional patterns were inferred from historical and community characterizations, and a succession model was constructed for the Blue Hills forest. In the absence of fire, the predominate streamside climax community is beech-magnolia; red oak-white oak-hickory is considered the climax community for most upland sites. Vegetation history and management: fire, agriculture, logging and fire exclusion have shaped current patterns of Blue Hills vegetation. This study supports the polyclimax theory which postulates that a "climax landscape" consists of a mosiac of communities responsive to edaphic, topographic, and climatic variables.
Wilkinson, Dan L. (1982). Analysis of upland and streamside vegetation in the upper Big Thicket. Texas A&M University. Texas A&M University. Libraries. Available electronically from
https : / /hdl .handle .net /1969 .1 /DISSERTATIONS -515425.