Ecosystems provide services essential for human survival, but for ecosystems to function well, they are thought to need sufficient ecological diversity. The physical structure of vegetation is thought to be closely linked to the functioning of ecosystems. We used data from over 3 million trees that covered continental North America to evaluate structural diversity – the physical arrangement of vegetation in ecosystems – as a predictor of the productivity of forest ecosystems.
We show that structural diversity is a robust predictor of forest productivity and consistently outperforms the traditional measure, species diversity, across climate conditions in North America. Structural diversity appears to be a better surrogate of niche occupancy because it captures variation in size that can be used to measure occupied niche space. Structural diversity is easy to measure and has high potential to be expanded to predict the productivity of ecosystems worldwide. Conservation and management could improve practices for enhancing ecosystem services by generally incorporating structural diversity into them.