Overlooking what is underground: Root:shoot ratios and coarse root allometric equations for tropical forests

Across our large and geographically comprehensive dataset, we found that R:S is negatively correlated with mean annual precipitation, and positively linked with stand age. However, information on root biomass allocation is still scarce in comparison with the wealth of available data on aboveground plant biomass in tropical forests, and more data will be necessary to understand the drivers of belowground biomass allocation. Moreover, the available root allometric equations show tremendous variation in mathematical form, which is likely related to the many different methods that have been used to quantify root biomass and its distribution with depth. A better understanding of belowground dynamics in tropical forests will require systematic surveys of root biomass along gradients of soil type, climate, and stand age, along with a streamlined protocol for developing root allometric equations.