Studies in the Numerical Analysis of Complex Rain-Forest Communities: I. A Comparison of Methods Applicable to Site/Species Data

Abstract
A set of data relating to 18 rainforest sites defined by the presence or absence of 818 vascular species is analysed by 4 numerical methods, 2 of which are novel. A Gower ordination proved the single most informative method; but computational considerations suggest that classification should be undertaken 1st, and ordination invoked only if classification proves unprofitable. Similar considerations apply to the new method of concentration analysis. The analyses reflect known environmental factors with great precision, and have clarified a complex interaction pattern. They recover the original intuitive physiognomicstructural classification only imperfectly, and the cause of this lack of complete correspondence requires further investigation. The results incidentally demonstrate that the basic floristic units which underlie the forest structure are vertically integrated and are not synusial; the wider implications of this observation are discussed.