Variation of C, N, and P stoichiometry in plant tissue, litter, and soil during stand development in Pinus tabulaeformis plantation
To estimate the ecological stoichiometry of Pinus tabulaeformis at different plantation stand ages,we investigated P.tabulaeformis plantations of 9,23,33,and 47 years old in the Ziwuling of Shaanxi province.This research of ecological stoichiometry was studied in order to guide the P.tabulaeformis forest productivity,and to improve and adjust the growth environment of such plantations.To this end,we investigated the carbon (C),nitrogen (N),and phosphorus (P) concentration,as well as their ratios in plant organs (leaf,branch,stem,and root),litter,and soil during stand development.Apart from root C concentration,the C,N,and P concentrations of the different plant organs,as well as their ratios,were significantly different in all plantation age groups.For all four age groups of P.tabulaeformis plantations,the C,N,and P concentrations,as well as the N ∶P ratios were highest in the leaf tissue,whereas the C ∶N and C ∶P ratios were highest in the stems.For other plant organs,no consistent patterns were found.For all plantation ages,all plant organ N ∶P ratios were lower than 14,except for leaf tissue from the 33-year-old P.tabulaeformis forest stand.Overall,the N ∶P ratios first increased,and then decreased with increasing forest age.These results imply that in this region,P.tabulaeformis is limited by N,and this N limitation decreases with increasing forest age.The litter and soil C,N,and P concentrations,as well as their ratios,were significantly different among the plantation age groups,with litter having higher concentrations than soil.Soil and litter C and P concentrations,as well as their C ∶N,C ∶P,and N ∶P ratios changed similarly with the increasing forest age,indicating a close relationships between soil and litter stoichiometry.There were significant correlations between the leaf tissue and litter N and P concentrations,as well as between their C ∶ N,C ∶P,and N ∶P ratios.However,no significant correlations between the leaf tissue and soil C,N,and P concentrations were found,suggesting that the supply of C,N,and P from the soil had little influence on plant tissue C,N,and P concentrations.
Pinus tabuliformis plantationforest agelittersoilC ∶ N ∶ P ecological stoichiometry
国家科技期刊平台
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万方数据
维普
