Improving ground cover and landscape function in a semi-arid rangeland through alternative grazing management

摘要

The development and adoption of sustainable grazing strategies is important to improve the functionality and productivity of agricultural landscapes. Alternative grazing systems incorporating periods of planned rest may achieve this compared to continuous grazing systems, but the evidence is conflicting. Using paired paddock contrasts, soil characteristics, ground cover and landscape function (i.e. soil stability, nutrient cycling, infiltration and landscape organisation indices) were compared between alternative grazing management (incorporating periods of rest), traditional (continuous) grazing, and areas managed for conservation (ungrazed by commercial livestock but grazed by native and feral herbivores) on contrasting soil types in semi-arid rangelands. Relationships between the response variables and understorey floristic biodiversity measures were also explored. Total ground cover was greater under conservation management than grazing, and was greater under alternative grazing than traditional grazing management. Indices of landscape function, including stability, nutrient cycling, patch area and landscape organisation were significantly greater, and interpatch length significantly shorter, under conservation compared to traditional grazing management. Alternative grazing management had intermediate values of landscape function which did not differ significantly to traditional grazing or conservation treatments. Ground cover and floristic biodiversity measures were often positively correlated, but there was no clear relationship between most landscape function and plant biodiversity indices. Landscape function may be important in detecting changes in rangelands that remain undetected by floristic diversity measures. Alternative grazing strategies incorporating planned rest have the potential to improve ground cover with the associated benefits of improved productivity and landscape function compared to continuous grazing regimes.