Forest Structure and Biodiversity on a Cloud Forest Lee Margin: Falling Trees and Calling Birds R. O. Lawton, R. M. Welch, U. S. Nair, K. N. Rabenold & W. A. Haber Northern Costa Rica RAMS simulated maximum wind speeds 20 m above the ground Monteverde study watershed ~12 ha; m A mapped study watershed to examine: 1) terrain related physiognomic trends 2) patterns of local species distribution in natural terrain units 3) distribution of individuals within populations 4) demographic processes 1 ha grid; 5 m contours What are the causes and correlates of the striking canopy heterogeneity? Trees fall down a lot. But the risk of treefall and gap formation is not uniform. Summary of Logistic Regression Analysis for Variables Predicting Treefall Gap Formation Model 2 = 8.29 df =2 p=.007 Risk Factor Likelihood ratio 95% CIZPr(>|z|) Intercept