Roller chopping and prescribed fire effects on herbaceous vegetation establishment and exotic grasses invasion in different locations of south Texas.

摘要

In semiarid environments, such as south Texas, allowing herbaceous native plant to re-establish from soil seed banks can benefit wildlife and domestic animals. The primary objective was to determine if reseeding following roller chopping in south Texas mixed brush communities result in increased cover of herbaceous vegetation. Invasion of exotic grasses into grasslands dominated by native plants changes fire cycles and reduces biodiversity. I tested the hypothesis that roller chopping and prescribed burning will result in an increase in exotic grasses; and previous disturbances alter the response of vegetation communities to wildfire compared to undisturbed areas. My results indicate that seeding is unnecessary after roller chopping to increase herbaceous vegetation cover in south Texas independently of the precipitation regime. The amount of herbaceous vegetation cover depends on the amount of precipitation, whether or not seeding was done after roller chopping. The effect of a wildfire on the establishment of either native or exotic species depends on previously disturbances and environmental factors.