Are above and belowground functional syndromes coupled across different species? An empirical test in the subtropical seasonally dry forests of central Argentina.

KOWALJOW ESTEBAN; CONTI GEORGINA; BROIERO XIMENA AYELÉN

Pirenópolis

Simposio; 59th Annual Symposium of the International Association of Vegetation Science; 2016

International Association of Vegetation Science

The functional approach has proved to be apowerful framework to analyze relationships between abiotic factors, communityfunctional composition and ecosystem processes. Across contrasting floras, ithas been extensively evidenced the existence of a leaf economic spectrum (LES)given by the association between leaf traits values, and reflecting afundamental trade-off between plant resource acquisition and conservation. Althoughthe existence of this trade-off have been mainly reported in studies focused onleaves, it have been hypothesized the existence of an integrated whole-plantstrategy, including stem and roots tissues. In the present work, we examinedthe relationship between 16 above and belowground functional traits from 5species (including trees, shrubs and grasses) in the subtropical seasonally dryChaco forests of Argentina, to test (i) if the widely supported LES also existsfor root traits values (RES), and (ii) if they are coordinated, defining awhole-plant economic spectrum. We found significant differences between speciesin almost all traits, revealing the differential occupation of functional spacein the economic spectrum. Aboveground traits values showed different orthogonalaxis for structural and leaf traits, which follow the LES, as expected. Acrossthe LES, the C4 grass was in the most acquisitive extreme, while the C3 grassoccupied the most conservative extreme. Regarding roots traits, we did not finda clear economic continuum, in comparison with the LES, where specific rootlength and nitrogen root content followed opposite directions in themultivariate distribution. Across the multivariate space, belowground traits showedhigher variation, with no clear position across a single axis. Although most individualpairs of associated leaf and root traits showed univariate coordination, chemicaltraits did not show significant relationships across leaf and root tissues, andso the LES and RES were weakly coupled across the sampled species. Our resultsindicate that other ecosystem processes could drive functional diversity andresource use belowground, where soil matrix is complex and spatiallyheterogeneous. The extent to which above and belowground functional strategiesare coordinated is important to understand plant species distributions andfunctioning and so, the impacts of land-use and climate change on ecosystemprocesses and services.