喀纳斯天然林乔灌草叶片及土壤碳氮磷化学计量特征

研究森林植被与土壤碳(C)氮(N)磷(P)化学计量关系是理解生态系统各组分的相互作用和探究植物的生长状况及生态适应性的关键。阿尔泰山天然林是我国北方典型的泰加林，在区域水汽、养分循环和多样性维持等方面发挥了重要作用。以喀纳斯天然林30种乔灌草植物及其生境为对象，运用方差分析、相关分析、冗余分析等方法研究植物叶片及土壤的化学计量特征及其相互关系，揭示喀纳斯天然林乔木、灌木和草本环境适应性的异同。结果显示：30种植物叶片C、N、P的平均含量分别为496.66 g/kg、23.87 g/kg、3.67 g/kg;叶片C∶N、C∶P、N∶P分别为26.52、160.91、6.74。不同生活型植物叶片C、N、P含量及其计量比间显著差异。其中C含量大小顺序为乔木>灌木>草本(P<0.05),N含量大小顺序为草本>灌木>乔木(P<0.05),灌木和草本之间叶片P含量差异不显著(P>0.05),但均显著高于乔木叶片P含量(P<0.05)。叶片C∶N和C∶P大小顺序均为乔木>灌木>草本(P<0.05),乔木和灌木叶片N∶P不存在显著差异(...

C,N,P stoichiometric characteristics of tree, shrub, herb leaves and soil in Kanas natural forests of Xinjiang Province, China

Study of forest vegetation and soil carbon (C), nitrogen (N), and phosphorus (P) stoichiometry relationships is key to understand the interactions of ecosystem components and explore the growth status and ecological adaptations of plants. We selected 30 major species of trees, shrubs and herbs in Kanas natural forests and their habitats as the research objects. ANOVA, correlation analysis and RDA analysis were used to comprehensively study the stoichiometric characteristics of plant leaves and soil and their interrelationships and to reveal the differences and similarities of environmental adaptation of trees, shrubs and herbs in Kanas natural forests. The results showed that the mean concentration of plants leaf C, N, and P were 469.66 g/kg, 23.87 g/kg, and 3.67 g/kg, respectively, in Kanas natural forests. C:N, C:P, and N:P ratios were 26.52, 160.91, and 6.74, respectively. There were significant differences in the leaf C, N and P contents and their stoichiometric ratios in different life forms of plants. The order of C content was tree > shrub > herb (P<0.05) and N content was herb > shrub > tree (P<0.05). The difference in leaf P content between shrubs and herbs was insignificant (P>0.05), but both were significantly higher than that of trees (P<0.05). The order of C:N and C:P ratios was tree>shrub>herb (P<0.05). Leaf N:P ratio of trees and shrubs were not significantly different (P>0.5), but both were significantly lower than herb N:P (P<0.05). Correlation analysis showed a highly significantly negative correlation (P<0.01) between C and N contents of the tree and herbaceous leaves, a significantly negative correlation (P<0.05) between C and P contents of herbaceous leaves, and a highly significantly positive correlation between N and P contents of shrub and herbaceous leaves. Soil organic carbon (SOC) and soil total nitrogen (STN) decreased with the increase in soil depth (P<0.05), while soil total phosphorus (STP) did not change significantly (P>0.05). There was a highly significantly positive correlation between SOC and STN, between STN and STP (P<0.01), while the correlation between SOC and STP was not significant (P>0.05). Redundancy analysis showed that herb leaf C, N, and P stoichiometry were more susceptible to soil factors than tree leaves, and shrub leaves were not affected by soil factors. This study focuses on the nutrient stoichiometry characteristics of leaves and soils of trees, shrubs and herbs in Kanas natural forests and their correlations, which are important for revealing the nutrient status characteristics of forest ecosystems in the region and providing theoretical data for the subsequent study of nutrient limitation in forest ecosystems in the area.