Plant-type dominates fine-root C:N:P stoichiometry across China: a meta-analysis

Aim: Fine roots play an important role in biogeochemical cycling in terrestrial ecosystems. However, our understanding of large scale biogeographic patterns and drivers of fine-root C:N:P stoichiometry is extremely limited.

Location: China.

Methods: We compiled data for fine-root carbon (C), nitrogen (N) and phosphorus (P) concentrations at 165 sites across China to explore large-scale biogeographic patterns and drivers of fine-root C:N:P stoichiometry.

Results: The geometric means of fine-root C, N, and P concentrations were 448.81 mg g-1, 10.73 mg g-1, and 0.9 mg g-1, respectively, whereas C:N, C:P and N:P ratios were 41.84, 508.32 and 11.73, respectively. The fine-root elemental concentrations and their ratios varied widely among plant groups and biomes, and showed clear latitudinal and longitudinal trends, as a consequence of differences in climate, soil and plant-type. However, plant-type was the largest contributor to the total variance in fine-root C, N, and P and their ratios compared to climate factors or soil features.

Main conclusions: The data reveal the existence of broad biogeographic patterns of fine-root C:N:P stoichiometry in China. These results advance our knowledge about the biogeochemical cycling of fine roots.