Past events and present environmental conditions may alter vegetation cover and composition over decadal timescales by exerting persistent effects on modern vegetation patterns and consequently influencing species distribution and abundance. My aim was to reconstruct vegetation and analyze cover during early-European settlement in Brazos County using historical sources, mainly the surveyor’s files from the Original Texas Land Survey. The decoded trees from the surveyor’s notes resulted in 24 witness and bearing tree species being recorded, the most abundant species on the uplands was Post Oak (Quercus stellata) and for bottomlands was Pin Oak (Quercus phellos). Using the distances and directions given in the surveyor’s notes for witness and bearing trees, coordinates were calculated and species classified according to their National Wetland Indicator’ (NWI) status. Indicator kriging was performed to create a continuous vegetation cover of Brazos County by interpolating the point biogeographical data (i.e., witness trees, bearing trees and stake, mound and post locations) that had been spatially located and mapped onto the shapefile.
The vegetation map showed 49% of vegetation in the county was covered by grassland during pre-European settlement. Most of these prairie areas were located in the northern portion of the county along the Old San Antonio Road. The bottomland forests covered 15% of Brazos County along the Navasota and Brazos Bottoms. Major expanses of bottomland hardwood occurred in the northwest of the county and at the confluence of the Navasota and Brazos rivers in the south. The Upland Oak Woodlands, mainly dominated by Post Oaks covered 36% of landscape, occurred mainly towards the western and eastern parts of the county and were interspersed with Grasslands. The vegetation map was verified using old photographs, traveler’s accounts and field checking for bottomland hardwoods. This research proves that the OTLS is a valid source for vegetation mapping during Pre-European settlement and for analyzing the tree species present at that time and helps in protecting and conserving our pristine environment at the present time.
| Identifer | oai:union.ndltd.org:tamu.edu/oai:repository.tamu.edu:1969.1/ETD-TAMU-2009-12-7496 |
| Date | 2009 December 1900 |
| Creators | Srinath, Indumathi |
| Contributors | Millington, Andrew |
| Source Sets | Texas A and M University |
| Language | en_US |
| Detected Language | English |
| Type | thesis, text |
| Format | application/pdf |
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