Examination and Analysis of the Impact of Climatic Factors on the Variability and Trends in Plant Species and Primary Productivity on the Texas Gulf Coast Prairie during a 3-4 Year Period.

The existing climate in an area significantly impacts plant species composition and primary productivity. Texas has been experiencing increasing drought periods over the past ten years, resulting in decreased crop yields, degraded pastures, and increased fires. The overall objective of this project was to examine and analyze the impact of climatic factors on the primary productivity, variability, and trends in plant species on a selected Texas Gulf Coast Prairie site.  A randomized block design consisting of 4 treatments and 4 replications with plot dimensions of 1 m² was used. Treatments included: 1) Control – Natural Grass Schedule with long, animal-based rotation (A); 2) Extended Pasture Grass Schedule (B); 3) Regular Pasture Grass Schedule (C), and 4) Regular Lawn Grass Schedule (D). Plant species diversity and patterns were be observed and recorded. Type of plant species were identified and recorded. All vegetation was clipped to a height of 5 cm above the soil surface, weighed (wet) and samples were air dried and reweighed to determine above ground biomass. Results indicated that average initial dry biomass for all treatments were 0.3, 0.31, 0.32, and 0.31 kg for treatments A, B, C and D, respectively. Results for treatment B showed that Coastal Bermuda and Perennial Rye Grass were the dominant plant species. For treatment C, Coastal Bermuda was the dominant plant species ranging from 41 to 67 % in May, 73 to 90% in June and 44 to 78% in July. For treatment D, Coastal Bermuda and Barnyard grass were the dominant plant species. Coastal Bermuda ranged from 62-71% in May, 49 -84% in June and 36 -78% in July. Data from SCAN site showed that average temperature for May, June and July were 21, 26, and 27⁰ C respectively, and accumulated rainfall amounts were 73, 97 and 100 cm.