Aim Carbon (C) and nitrogen (N) stoichiometry is a critical indicator of biogeochemical coupling in terrestrial ecosystems. However, our current understanding of C : N stoichiometry is mainly derived from observations across space, and little is known about its dynamics through time. Location Global secondary forests.
Methods We examined temporal variations in C : N ratios and scaling relationships between N and C for various ecosystem components (i.e. plant tissue, litter, forest floor and mineral soil) using data extracted from 39 chronosequences in forest ecosystems around the world.
Results The C : N ratio in plant tissue, litter, forest floor and mineral soil exhibited large variation across various sequences, with an average of 145.8 +- 9.4 (mean +- SE), 49.9 +- 3.0, 38.2 +- 3.1 and 18.5 +- 0.9, respectively. In most sequences, the plant tissue C : N ratio increased significantly with stand age, while the C : N ratio in litter, forest floor and mineral soil remained relatively constant over the age sequence. N and C scaled isometrically (i.e. the slope of the relationship between log-transformed N and C is not significantly different from 1.0) in litter, forest floor and mineral soil both within and across sequences, but not in plant tissue either within or across sequences. The C : N ratio was larger in coniferous forests than in broadleaf forests and in temperate forests than in tropical forests. In contrast, the N-C scaling slope did not reveal significant differences either between coniferous and broadleaf forests or between temperate and tropical forests.
Main conclusions These results suggest that C and N become decoupled in plants but remain coupled in other ecosystem components during stand development.
Publication Yang, Y.H. and Y.Q. Luo. 2010. Carbon: nitrogen stoichiometry in forest ecosystems during stand development.. Global Ecology and Biogeography. doi: 10.1111/j/1466-8238.2010.00602.x.
Data Set (Download File)