Determinants of Spatial Pattern in Saxicolous Lichen Communities

Abstract

In order to obtain a complete picture of the factors determining spatial pattern in a saxicolous lichen community (or any other plant community) it is important to use a range of analytical techniques at a variety of scales. The Jonas Rockslide study is an example of this, and three analyses from this study are discussed here. Each scale gives a different perspective on the processes acting in the community. The largest scale shows that lichen distributions are correlated with attributes of whole rockfaces such as slope and aspect. The second analysis examines pattern at the scale of 10 cm to 20 cm grid points and shows that within a rockface are many micro-habitats, reflected in the pattern of occurrence of different lichen species at this scale. The smallest scale of analysis is a ‘nearest-neighbour’ analysis, which indicates that lichens sample their environment differently and have different ecological strategies. These processes ultimately act together to give the observed pattern in the community.