Abstract:

Aims Studies on the relationship between leaf and fine root traits provide insights into interactions among plant functional traits, plant strategy for resource acquisition and mass partitioning, and predictive models for fine root traits. Our main objectives were to test if leaf and fine root traits vary in a coordinated pattern in typical temperate grassland and to determine to what extent inter- and intra-specific leaf and fine root traits exhibit structural and functional convergence.

Methods During July and August 2006, we measured nitrogen (N) and phosphorus (P) concentrations, N:P ratios of leaves and fine roots (diameter < 2 mm), specific leaf area and specific root length of 65 grassland species in Xilin River Basin, Inner Mongolia. We statistically analyzed correlations between leaf and fine root traits among and within species.

Important findings At the inter-specific level, N concentrations, P concentrations and N:P ratios of leaves and fine roots were significantly correlated, while specific leaf area and specific root length showed a weak relationship. Species from different functional groups differ in the correlation pattern. In dicotyledons there was a strong correlation between leaf and fine root N concentrations, but not in P concentrations. In contrast, monocotyledons had a positive relationship between leaf and fine root P concentrations, but not N concentrations. Observed inter-specific correlations between above and belowground traits weakened or disappeared when examined at the intra-specific level. Thus, leaf and fine root traits were generally correlated among species, while correlations were weak within species.

Key words: ecological stoichiometry, functional traits, specific leaf area, specific root length, temperate grassland