Indicator species for the interpretation of vegetation condition in the St Bathans area, central Otago, New Zealand

Monitoring the effect of management in rangelands is an integral part of the process of adaptive management. An understanding of how individual species react to management has two major benefits. Firstly, monitoring, can be simplified by avoiding species which are reacting mostly to other influences, and secondly the abundance of species can be interpreted in a meaningful way for assessing the influence of previous management. Gradient analysis on a matrix of 69 sample sites and 125 species in the St Bathans area of Central Otago identified a relatively homogenous data set, within which the effects of environmental variation had been minimised so that the major pattern of vegetation composition change was explained by pastoral impact. Ten plant species showed clear responses along the pastoral impact gradient, and were abundant over certain ranges of this gradient. It is recommended that these species be used to monitor trends in vegetation condition.