Treesearch

Spotfires have and always will be a problem that burn bosses and fire crews will have to contend with on prescribed burns. Weather factors (temperature, wind speed and relative humidity) are the main variables burn bosses can use to predict and monitor prescribed fire behavior. At the Oklahoma State University Research Range, prescribed burns are conducted during different seasons of the year and in different fuel types all over the state of Oklahoma. Since 1996 records have been kept to track spotfires that occur on these prescribed burns. Most of these spotfires were due to firebrands...

Prescribed fire is used to reduce rate of mesquite (Prosopis glandulosa) encroachment and dominance on grassland ecosystems, but is difficult to apply in continuousgrazed systems because of the difficulty in accumulating sufficient herbaceous biomass (that is, ‘fine fuel’) that is needed to fuel fire. We evaluated the potential of rotationally grazing cattle as a means to defer grazing to provide fine fuel burning. Mesquite cover changes from 1995 to 2000 were compared in four systems: continuous grazing, mesquite untreated (Cont.), 4 pasture/1 herd with fire (4:1F), 8 pasture/1 herd with...

Fire in sagebrush rangelands significantly alters canopy cover, ground cover, and soil properties that influence runoff and erosion processes. Runoff is generated more quickly and a larger volume of runoff is produced following prescribed fire. The result is increased risk of severe erosion and downstream flooding. The Water Erosion Prediction Project (WEPP), developed to model erosion on cropland, forest, and rangeland, is a tool that has the potential to model erosion and help managers address erosion and runoff risks following fire. WEPP views erosion as two processes: interrill and...

The leguminous Caragana species are important components of vegetation in the semi-arid Loess-gully region, China. These shrub species are important for maintaining the dynamics and function of the ecosystem in the region. They are potential plant resources for restoration of degraded ecosystems. The germination responses to temperatures in two indigenous and one exotic Caragana species were studied under controlled conditions in the laboratory. Treatments were nine temperature regimes (constant temperatures of 5, 10, 15, 20, 25, and 30°C and three alternating day/night temperature regimes...

A large scale ecosystem restoration program was initiated in 1997 on the Pecos River in western Texas. Saltcedar (Tamarix spp.), a non-native invasive tree, had created a near monoculture along the banks of the river by replacing most native vegetation. Local irrigation districts, private landowners, federal and state agencies, and private industry worked together to formulate and implement a restoration plan, with a goal of reducing the effects of saltcedar and restoring the native ecosystem of the river. An initial management phase utilizing state-of-the-art aerial application of...

This study quantified honey mesquite (Prosopis glandulosa) root growth and water use efficiency following chronic soil drought or wetness on a clay loam site in north Texas. Root systems of mature trees were containerized with barriers inserted into the soil. Soil moisture within containers was manipulated with irrigation (Irrigated) or rain sheltering (Rainout). Other treatments included containerized precipitation-only (Control) and noncontainerized precipitation-only (Natural) with three trees per treatment. After four years of treatment, soil cores to 2.7 m depth were obtained beneath...

Prescribed burning to restore grasslands is more complicated than just setting a fire or, worse, letting a fire burn. We will examine how fire may be used to restore a more desirable landscape. First, any area that might be considered for prescribed fire should be thoroughly evaluated. Soils are paramount as they will indicate what we can expect from a given site. Then, we should study the plant community which originally existed on the site. Comparing the original plant community to the current plant community will help us construct a viable set of objectives. Second, we will determine...

Prior to development of the livestock industry, both anthropogenic and natural disturbances (such as prescribed and wild fire) played key roles in shaping the different plant communities across Texas. Historically, fires occurred during all seasons of the year, but summer fires were probably more frequent due to dry conditions combined with increased lightning frequency during the summer. When fire was frequent, the upland or western divide region of the Edwards Plateau was typical of a savanna ecosystem. The purpose of this study was to determine the effects of summer and winter burning...

The Rio Grande Plains (RGP) and Coastal Prairie (CP) of South Texas is the southernmost extension of the Great Plains Grasslands. Fire, along with other climatic variables, such as drought, presumably maintained mesquite (Prosopis glandulosa Torr.) savannas and interspersed grasslands of pre- European settlement South Texas. Frequency of fire appeared to be highly variable and ranged from 5 to 30 years (Wright and Bailey 1982). Following European settlement, the change from grassland to woodlands/shrublands was accelerated by introduction of livestock and fencing. Domestic animals served...

Wildfire is an important ecological process and management issue on western rangelands. Fire suppression activities in the past century have increased the number and severity of wildfires, resulting in increased soil erosion and decreased water quality. Many infiltration studies on rangeland have shown that litter and vegetation cover protect the soil and enhance infiltration. After fire, water repellency is typically found on the soil surface or a few centimeters below and is also common on unburned rangelands and dry soils conditions. However, the causal agents of water repellency are...