Abstract:
1. The question whether the strategies of above-and belowground plant organs
are coordinated as predicted by the plant economics spectrum theory is still
under debate. We aim to determine the leading dimensions of tree trait variation
for above-and belowground functional traits, and test whether they represent
spectra of adaptation along a soil fertility gradient in tropical Andean
forests.
2. We measured leaf, stem and fine root functional traits, and individual-level
soil nutrient availability for 433 trees from 52 species at three elevations between
1000 and 3000 m a.s.l.
3. We found close coordination between above– and belowground functional traits
related to the trade-off between resource acquisition and conservation, whereas
root diameter and specific root length formed an independent axis of covarying
traits. The position of a tree species along the acquisition–conservation axis of
the trait space was closely associated with local soil nitrogen, but not phosphorus,
availability.
4. Our results imply that above-and belowground plant functional traits determine
at which edaphic microhabitats coexisting tree species can grow, which is potentially
crucial for understanding community assembly in species-rich
tropical montane forests.
