title: Prediction of in situ root decomposition rates in an interspecific context from chemical and morphological traits.
abstract: OBJECTIVE
  We quantitatively relate in situ root decomposition rates of a wide range of trees and herbs used in agroforestry to root chemical and morphological traits in order to better describe carbon fluxes from roots to the soil carbon pool across a diverse group of plant species.
  
  
  METHODS
  In situ root decomposition rates were measured over an entire year by an intact core method on ten tree and seven herb species typical of agroforestry systems and were quantified using decay constants (k values) from Olson's single exponential model. Decay constants were related to root chemical (total carbon, nitrogen, soluble carbon, cellulose, hemicellulose, lignin) and morphological (specific root length, specific root length) traits. Traits were measured for both absorbing and non-absorbing roots.
  
  
  RESULTS
  From 61 to 77 % of the variation in the different root traits and 63 % of that in root decomposition rates was interspecific. N was positively correlated, but total carbon and lignin were negatively correlated with k values. Initial root traits accounted for 75 % of the variation in interspecific decomposition rates using partial least squares regressions; partial slopes attributed to each trait were consistent with functional ecology expectations.
  
  
  CONCLUSIONS
  Easily measured initial root traits can be used to predict rates of root decomposition in soils in an interspecific context.
authors: Département de Biologie, Université de Sherbrooke, Sherbrooke, Québec J1K2R1, Canada.
authors: Maurice
authors: M
authors: Aulen
authors: Bill
authors: B
authors: Shipley
authors: Robert
authors: R
authors: Bradley
mesh_terms: D001692:Biological Transport; D002244:Carbon / Q000378:metabolism; D002482:Cellulose / Q000378:metabolism; D008031:Lignin / Q000378:metabolism; D009584:Nitrogen / Q000378:metabolism; D018517:Plant Roots / Q000737:chemistry / Q000254:growth & development / Q000378:metabolism*; D006109:Poaceae / Q000737:chemistry / Q000254:growth & development / Q000378:metabolism; D011134:Polysaccharides / Q000378:metabolism; D011792:Quebec; D012987:Soil / Q000737:chemistry*; D014197:Trees / Q000737:chemistry / Q000254:growth & development / Q000378:metabolism*
chemical_list: D011134:Polysaccharides; D012987:Soil; D002244:Carbon; C007916:hemicellulose; D002482:Cellulose; D008031:Lignin; D009584:Nitrogen