The Texas Parks and Wildlife Department is cooperating with private, state, and federal partners to produce a new land classification map for Texas, based on the NatureServe Ecological System Classification System as described by Comer (2003). The basic steps are to identify mapping sub-systems using ecological systems as a starting point, to collect data from air photos and the field to implement a supervised classification, and to use ecoregions, SSURGO soils, DEM-based variables, and hydrology to help interpret the ecological meaning of final mapping targets.
Rapid collection of field data is accomplished by combining ecological expertise with GIS data collection techniques. Improved thematic and spatial resolution is achieved using a decision tree classifier with both remotely sensed and abiotic variables, map objects generated at 10 m resolution, and the modeling of mapping targets using ecological site descriptions from SSURGO soils and data from the NatureServe systems classifications.
Phases 1, 2 and 3 of the project are complete. These phases cover 80,168,327 acres (32,442,971 hectares) or approximately 55% of the project area or 47% of Texas Land Area. There are 73 Ecological Systems mapped in Phases 1 thru 3 and 288 mapping subsystems.
Project and partner ecologists have produced detailed descriptions of all Ecological systems and Mapping Sub-systems that occur within Phases 1 thru 3. This includes floristic details refined by field sampling data collected by project personnel, ecological processes, such as fire, grazing, flooding that formed or maintains the systems, and the soils and geology that influence the systems. Project ecologists have also developed an Interpretive Guide that includes a general description of each Ecological system and subordinate Mapping Sub-systems, a representative photo of most Mapping Sub-systems, a list of public properties where an example of each system may be viewed, and a map showing the mapped distribution of each sub-system. The interpretive guide also includes a detailed project methodology and ecological information on select eco-regions.
Field data is being collected for each phase of the project. In 300+ days in the field, the plant ecologist collected 7456 data points in 225+ mapping subsystems. 2900 data points were collected in 90 mapping systems for Phase 1. 1875 data points were collected in 98 mapping systems in Phase 2. 2108 ground truth points have been collected within 123 systems for Phase 3. To date, 573 field ground truth points within 79 mapping systems have been collected for Phase 4.
Field data will be available for public use. Data are being used to explain the range of native plant species like the Loblolly Pine, and explore the distribution of exotic invasive species. Wildlife biologists are interested in applying these data to model potential habitat for several species of animals.
[Comer, P., D. Faber-Langendoen, R. Evans, S. Gawler, C. Josse, G. Kittel, S. Menard, M. Pyne, M. Reid, K. Schulz, K. Snow, and J. Teague. 2003. Ecological Systems of the United States: A Working Classification of U.S. Terrestrial Systems. NatureServe, Arlington, Virginia.]
Partners with TPWD: