Vegetation Responses to Roller Chopping and Buffelgrass Seeding in Argentina

T-4464 Buffelgrass (Cenchrus ciliaris L.) is an introduced grass used extensively for restoring forage capacity of denuded shrublands in the arid Chaco region in central western Argentina. Currently, the technique of roller chopping and simultaneous buffelgrass seeding is widespread, but information is lacking about its effects on forage production and other vegetation attributes at the regional scale. The purpose of our study was to compare grass yield; vegetation cover and density; and species richness, diversity, and evenness, between roller chopping and simultaneous buffelgrass seeding with nontreated native degraded shrublands. Eight sites, including matched pairs of treated and nontreated areas, were studied. Grass yield, total perennial grass cover, and total perennial grass density were higher (P 0.05) between treated and nontreated areas were detected in tree cover and density, species number, diversity index, and evenness. The results of this study indicate that, in the short term, roller chopping and simultaneous buffelgrass seeding produces rapid increases in grass cover and grass yield, and a drastic reduction in shrub cover without affecting species diversity on degraded shrublands of the arid Chaco region of Argentina. El buffel T-4464 (Cenchrus ciliaris L.) es un pasto introducido, utilizado para restaurar la capacidad forrajera de matorrales degradados en el sector centro-occidental de la región del Chaco árido, Argentina. En la actualidad el rolado y siembra simultánea de buffelgrass está ampliamente difundido en la región. Sin embargo, se carece de información a nivel regional, relacionada con los efectos de la aplicación de esta técnica sobre la producción de gramíneas y otros atributos de la vegetación. El objetivo de nuestro estudio fue comparar diferentes atributos de la vegetación entre áreas roladas y sembradas con pasto buffel y matorrales degradados (testigo). Para ello se seleccionaron ocho áreas roladas y sembradas, y ocho áreas testigo adyacentes. Se evaluó la producción de gramíneas, la cobertura y densidad de la vegetación, y el número de especies, diversidad y equitatividad. La p