Browsing Journal of Range Management, Volume 54, Number 6 (November 2001) by Subjects
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Adoption of Brush Busters: Results of Texas county extension surveyChanging landowner demographics and the increasing recognition that some quantity of woody plants is valuable for certain rangeland management objectives has led to increasing interest in selective brush management practices. Brush Busters is a collaborative extension/research program developed in response to this growing interest. A survey of Texas County Extension Agents-Agriculture was conducted in 1999 to determine their perceptions about the interest in and adoption of Brush Busters practices. Using 3 threshold photographs, Extension Agents representing almost 50% of the counties in the 9 Extension Districts surveyed estimated that 44, 34, and 49% of the total area of mesquite, juniper and pricklypear, respectively, could be treated using Brush Busters. They also indicated that over 405,000 ha (78% mesquite) were treated with Brush Busters methods between 1995 and 1998, but that this represented less than 7% of the potentially treatable area. In most Extension Districts, more time was spent disseminating information about Brush Busters methods than any other brush management method since 1995. Extension Agents indicated that Brush Busters has become popular because it is perceived to be an inexpensive, convenient, safe, effective and predictable method for controlling brush, and because user-friendly information is widely available. Our findings suggest that increasing the adoption rates of ecologically sound rangeland management technologies requires: (1) greater emphasis on developing and disseminating user-friendly messages to rangeland managers and Extension Agents; and (2) greater emphasis on short-term efficacy rather than the long term advantages of new technologies.
Mesquite and grass interference with establishing redberry juniper seedlingsExcessive cover of juniper (Juniperus pinchotii Sudw.) reduces forage production, interferes with livestock management, and diminishes the watershed and wildlife habitat values of rangelands. We studied whether juniper seedlings were differentially suppressed in the presence of different grass species, and to what extent established mesquite (Prosopis glandulosa Torr.) trees facilitated or competed with establishing juniper seedlings. Seedlings growing with any of the grasses (RGR = 0.23 to 0.43 cm cm(-1)) grew significantly less than those with no grass competition (RGR = 0.72 cm cm(-1))(P < 0.01). Juniper seedlings grew significantly less in the presence of buffalograss (Buchloe dactyloides (Nutt.) Engelm.) (RGR = 0.23 cm cm(-1) than with either sideoats grama (Bouteloua curtipendula (Michx.) Torr.) (RGR = 0.43 cm cm(-1)) or tobosagrass (Hilaria mutica [Buckl.] Benth.) (RGR = 0.43 cm cm(-1))(P < 0.01). In contrast, juniper seedlings grew larger under intact canopies of mesquite (RGR = 0.99 cm cm(-1)) than in open grassland (RGR = 0.65 cm cm(-1))(P < 0.05) due in part to the greater nutrient availability (P < 0.05) under mesquite canopies. Juniper growing in sub-canopy positions with mesquite trees removed grew less (RGR = 0.84 cm cm(-1)) than those growing under mesquite canopies with root competition (RGR = 0.99 cm cm(-1))(P < 0.05). Juniper growing under intact mesquite canopies but without mesquite root competition, grew no better or worse (RGR = 0.93 cm cm(-1)) than those with mesquite root competition (RGR = 0.99 cm cm(-1))(P > 0.05), indicating that mesquite root competition with juniper is probably inconsequential. Since junipers grow mainly in fall, winter and spring when mesquite trees are dormant and leafless, the lack of competition may largely be due to these 2 species using resources at different times of the year. Greater nutrient availability beneath mesquite canopies, reduction of summer temperatures, and temporal separation of resource use clearly benefit juniper seedlings growing in the presence of mesquite. Managing for a vigorous grass component with low densities and cover of mesquite is the best way to limit the rate of invasion by juniper.