The distance dependence prediction of the Janzen-Connell hypothesis: a meta-analysis

The Janzen‐Connell hypothesis explains the maintenance of tropical diversity through the interacting effects of parent‐centered dispersal patterns and distance‐ and density‐dependent propagule survival. These effects were thought to support regular spacing of species within tropical forest, enhancing diversity. One of the predictions of the hypothesis is that seed and seedling survival should improve with increased parental distance, due to reduced predation with increased parental distance. Although there are many independent tests of this hypothesis for individual species, there are few synthetic studies that have brought these data together to test its validity across species. Therefore, this data set was created as a part of a meta‐analysis of the effect of distance on enhancing propagule survival. It contains the results of 40 experimental studies which tested the above-mentioned distance dependent prediction of the Janzen-Connell hypothesis, by examining spatial patterns of seed and seedling predation.