Regression tree analysis of the fish species richness at Lizard Island, QLD, Australia.

<p>The explanatory variables were: site, topographic complexity, habitat diversity, coral species richness, coral diversity, percent hard coral cover, branching coral cover and corymbose coral cover. For each of the four terminal nodes the distribution of the observed values of fish species richness is shown in a histogram. Each node is labeled with the mean rating and the number of observations in a group (in parentheses). The tree explained 70.5% of the total variability in the data. The first and second splits based on coral species richness explained 56.4% and 7.2% respectively, the third split based on percent hard coral cover explained additional 6.9%.