The interspecific growth-mortality trade-off is not a general framework for tropical forest community structure

Using demographic data for 1,111 tree species across ten tropical forests, the authors test the generality of the growth-mortality trade-off, finding that it holds in undisturbed but not disturbed forests. Resource allocation within trees is a zero-sum game. Unavoidable trade-offs dictate that allocation to growth-promoting functions curtails other functions, generating a gradient of investment in growth versus survival along which tree species align, known as the interspecific growth-mortality trade-off. This paradigm is widely accepted but not well established. Using demographic data for 1,111 tree species across ten tropical forests, we tested the generality of the growth-mortality trade-off and evaluated its underlying drivers using two species-specific parameters describing resource allocation strategies: tolerance of resource limitation and responsiveness of allocation to resource access. Globally, a canonical growth-mortality trade-off emerged, but the trade-off was strongly observed only in less disturbance-prone forests, which contained diverse resource allocation strategies. Only half of disturbance-prone forests, which lacked tolerant species, exhibited the trade-off. Supported by a theoretical model, our findings raise questions about whether the growth-mortality trade-off is a universally applicable organizing framework for understanding tropical forest community structure.

Automated summary

This study analyzed demographic data of 1,111 tree species in tropical forests and found that the growth-mortality trade-off is more pronounced in undisturbed forests compared to disturbed forests. The research suggests that resource allocation strategies play a key role in determining the trade-off, raising questions about its universality in understanding tropical forest community structure.