摘要:Among the most pronounced large-scale geographic patterns of plant biodiversity are the
increase in plant species richness towards the tropics, a more even distribution of the
relative abundances of plant species in the tropics, and a nearly log-normal relative
abundance distribution. Here we use an individual-based plant diversity model that relates
climatic constraints to feasible plant growth strategies to show that all three basic diversity
patterns can be predicted merely from the climatic constraints acting upon plant
ecophysiological trade-offs. Our model predicts that towards objectively 'harsher'
environments, the range of feasible growth strategies resulting in reproductive plants is
reduced, thus resulting in lower functional plant species richness. The reduction of
evenness is attributed to a more rapid decline in productivity from the most
productive to less productive plant growth strategies since the particular setup of the
strategy becomes more important in maintaining high productivity in harsher
environments. This approach is also able to reproduce the increase in the deviation from
a log-normal distribution towards more evenly distributed communities of the
tropics. Our results imply that these general biodiversity relationships can be
understood primarily by considering the climatic constraints on plant ecophysiological
trade-offs.