USING GEOGRAPHIC INFORMATION-SYSTEMS (GIS) TO DETERMINE THE ADEQUACY OF SAMPLING IN VEGETATION SURVEYS

Data from biological surveys are increasingly being used for making land use and management decisions, and as input in predictive models. Biased or inadequately sampled data sets may result in misleading predictions and lead to poor management decisions. Five methods for assessing the adequacy of sampling in vegetation surveys using Geographic Information Systems (GIS) were investigated The methods were wed and assessed on a 1:250,000 scale vegetation survey on Cape York Peninsula, Australia. For surveys in progress, the Intuitive Reliability Assessment (Method 1) and Sampling Intensity Index (Method 2) were found to be very useful at identifying undersampled plant assemblages and areas. Non-stratified Environmental Parameter Analysis (Method 3) and Environmental Domain Analysis (Method 5) gave only, general assessment of al eas requiring fur ther sampling. For more specific identification of supplementary sampling sites, the complementary use of Methods 1 or 2 was required. However, Methods 3 and 5 together with Gradsect Evaluation using DOMAIN (Method 4), can assist in the planning of comprehensive and efficient sampling strategies for new surveys. The results of this study have application to a wide range of natural resource surveys.