Leaf stoichiometry of trees in three forest types in Pearl River Delta, South China

Aims Plant or biomass stoichiometry can be used to distinguish biological entities (genes, cells, organisms, etc.) based on element composition. Our objective was to determine the stoichiometry characteristics and examine nutrient limitation in evergreen broad-leaved forest, coniferous and broad-leaved mixed forest and coniferous forest. Methods We determined C, N, P stoichiometry of leaves of 19 dominant trees of 16 taxa in three forest types at the Pearl River Delta Forest Ecosystem Research Station, Guangdong Province, South China. Important findings Leaf stoichiometry showed large variations: C ranged from 434 to 537 mg·g–1, N from 6.8 to 23.0 mg·g–1, P from 0.56 to 2.10 mg·g–1, C:N from 21.22 to 70.74, C:P from 227.14 to 844.64 and N:P from 5.26 to 20.91. Leaf N, P, C:N and C:P were linearly correlated (p 0.01). Leaf C, C:P and N:P (weighted average ± standard deviation: (517.85 ± 35.96), (727.47 ± 231.52) and (15.71 ± 3.76) mg·g–1, respectively) were the highest in coniferous forest, followed by mixed forest (509.47 ± 19.38, 553.01 ± 152.32 and 10.93 ± 1.89, respectively) and evergreen broad-leaved forest (481.59 ± 18.35, 412.19 ± 200.91 and 9.46 ± 4.28, respectively), and a reverse sequence was detected for leaf P content. The sequence for N content was coniferous forest ((12.20 ± 5.65) mg·g–1) evergreen broad-leaved forest ((11.50 ± 4.24) mg·g–1) mixed forest ((10.51 ± 5.22) mg·g–1) and for C:N was mixed forest (51.35 ± 13.65) coniferous forest (47.40 ± 15.85) evergreen broad-leaved forest (45.59 ± 14.70), and higher nutrient use efficiency was discovered in three forest types. Several evergreen broad-leaved trees and evergreen broad-leaved forest had shortages of N.