Effects of Neighborhood Tree Species Diversity on the Stoichiometric Ratios of Nitrogen to Potassium,Calcium,and Magnesium in Cunninghamia lanceolata leaves
[Objective]This study aims to explore the impact of neighboring tree species diversity on element stoichiometry in subtropical forest ecosystems,in order to provide scientific basis for nutrient utilization efficiency in the selection of afforestation tree species in subtropical regions.[Method]Based on tree diversity and a large-scale ecosystem function experimental platform,plots with different tree species richness(1,4,8,16,32)were selected,with Chinese fir(Cunninghamia lanceolata)as the target tree species,and 8 target trees were selected in the central area of each plot.The nutrient concentration of nitrogen(N),potassium(K),calcium(Ca)and magnesium(Mg)in leaves were measured,and the dissimilarities of functional traits between its neighbors were calculated.Linear mixed-effect models were used to study the effects of neighbor tree species richness,functional trait dissimilarities among tree species,and neighbor tree height index on the stoichiometric ratios of N∶K,N∶Ca and N∶Mg in target tree leaves.[Result]1)High dissimilarities in specific leaf areas between the target tree and its neighbor trees significantly reduced the ratios of N∶K and N∶Mg of the target tree's leaves,but did not affect the N∶Ca.2)The species richness of neighbor trees increased N∶Mg of the leaves of the target trees.3)The neighbor tree height index(shading effect)significantly reduced the N∶Ca ratio of the target tree leaves.As the shading increased,the effect of dissimilarity in root tissue density between Chinese fir and neighboring trees on the N∶Ca ratio in Chinese fir leaves shifted from positive to negative.[Conclusion]Establishment of mixed forests in subtropical regions is beneficial for increasing the functional trait dissimilarities between neighboring tree species,enhancing the utilization of calcium,magnesium,and potassium nutrient resources,and improving the nutrient balance of Chinese fir.
tree species richnessfunctional traitheight indexniche complementarity
国家科技期刊平台
NSTL
万方数据
