Evaluation of Texas Native Grasses for TxDot Right of Ways: Technical Report

摘要

The Texas Department of Transportation (TxDOT) has one of the largest right-of-way areas in the United States with over 127,138 km of state maintained highway. In 2003, the new guidelines for Texas Pollution Discharge Elimination System went into effect causing a renewed interest in TxDOTs strive to establish vegetation as quickly as possible. These guidelines, along with executive orders signed in 1999 and 2000, have brought about a growing interest in reducing spread and establishment of invasive nonnative plant species, with emphasis on maintaining or increasing native species diversity and restoring ecosystem processes. A two-year study was conducted in Andrews, Baylor, and Kleberg Counties in Texas. Our objectives were to test the hypotheses that (1) two native species, hooded windmillgrass (WMG) and shortspike WMG, provide similar vegetation canopy cover as the standard seed mixtures currently used by TxDOT when added as a component in a native seed mixture; (2) native WMGs would provide similar vegetative cover as bermudagrass with use of a soil retention blanket; (3) hooded and shortspike WMGs provide similar canopy cover as bermudagrass (Cynodon dactylon) on single species plots; and (4) drill planting technique would allow a greater proportion of seeds planted to establish a root system, therefore providing greater canopy cover when compared against a broadcasting technique.