Pollen Production and Plant Density Affect Pollination and Seed Production in Taxus Canadensis

Abstract

Mean pollen production and mean nearest neighbor distance were recorded for several populations of Taxus canadensis and correlated with the proportion of ovules pollinated and seed set. Distance and pollen production together explained 86% of the variation in pollination success, each variable significantly adding to the regression when adjusting for the other. Seed set was correlated significantly with pollen production and nearest neighbor distance separately, but the multiple regression including the latter two variables was not significant. Seed set was correlated most strongly with pollination success and mean ovule production (R2 = 0.7), suggesting that variation in seed set among Taxus populations was a combination of differences in pollen and resource availability.