A survey approach to evaluating the effects of management on semi-arid lands in New South Wales.

Abstract

One hundred and ten paddocks were surveyed to give an overview of the effects of management burning, grazing by cattle, goats and sheep, and protection from livestock, on major vegetation types in the rangelands. A commercial paddock scale was used to complement information previously available on dietary preferences of livestock from a few, small research sites. In this dry period study, estimates of woody and herbaceous cover were not significantly different overall among paddocks subjected to the various kinds of management. However, herbaceous cover in protected or spelled paddocks was better than in the others. Also, no significant relationships were found between woody cover and herbaceous biomass in any treatment. Despite moderate sample sizes, high coefficients of variation occurred throughout the results. These were regarded as being a true reflection of the variability between paddocks in the rangeland. Underlying differences between management types may have been masked by the heterogeneity of the paddocks within each type due to a complex history of rainfall, burning and grazing. Cluster analysis of the 110 paddocks revealed floristic (woody spp.) similarities of mulga, poplar-box, pine and some belah-rosewood woodlands, whereas saltbush and mallee were distinct. Further comparisons of management types were made on mulga woodland alone. Domestic goats were kept in the most heavily wooded paddocks and, in contrast with sheep, checked the growth of woody plants < 2m high. Woody growth recovered in the < 2m stratum several years after burning. Further evaluation of the herbaceous layer and of woody/herbaceous relationships is recommended after a wet summer.