Root anatomy helps to reconcile observed root trait syndromes in tropical tree species

Studying the organization of functional traits in plant leaves and stems has revealed notable patterns linking function and form; however, evidence of similarly robust organization in root tissues remains controversial. We posit that anatomical traits in roots can provide insight on the overall organization of the root system. We hypothesize that A) size variation in the tissue outside the stele relates in a non-linear fashion with functional traits associated with direct resource uptake, including a negative relationship with root architectural traits; and B) similar relationships detected in tropical areas also hold true in other biomes.

We address our hypotheses using empirical data from 24 tropical tree species in French Guiana, including anatomical measurements in first order roots, and functional trait description for the entire fine root system. In addition, we compiled a global meta-analysis of root trait with 500+ forest species across tropical, subtropical and temperate for...