摘要:川中丘陵区柏木纯林存在生物多样性降低、水土保持能力减退、生产力低下、地力衰退等问题，已成为亟待改善的低产低效林分。通过开窗补植银木进行乡土阔叶树种的针阔混交，以柏木纯林和银木林窗区域林分的植物-凋落物-土壤为研究对象，对比分析C、N、P元素含量及比值，讨论阔叶树种引入后林分生态化学计量特征的变化情况。结果表明：（1）柏木叶片C：N在12月份为132.79，而在次年的4月下降到了84.91，银木叶片年均C：N为52.6，低的C：N体现出银木在幼龄阶段快速生长的特点。（2）柏木与银木叶片N：P分别为10.77，10.64都明显处于N限制的阈值以下，生长过程主要受到了N元素的限制。（3）林窗中银木凋落物N含量高于柏木，C：N、N：P小于柏木，土壤与"植物-凋落物"间的相关性增加。因此，阔叶树种的引入有利于提高分解的相对速率，触发森林土壤养分循环过程。



Abstract:The pure cypress forest in the central Sichuan hilly area has problems of reduced biodiversity, lowered capacity for water and soil conservation and underground productivity, and land degradation. The stands in this area are inefficient real-estate and candidates for improvement. The cedar pure forest mixed mass, mixed tree species selected for the Cinnamomum septentrionale, which is an indigenous broadleaf species. The plants, litters, and soils in a mixed forest of cypress and Cinnamomum septentrionale forest were used as the research object. The contents of C, N, and P were compared and analyzed. The changes in ecophysiological characteristics after the introduction of the broadleaf trees are discussed. The results showed:(1) C:N of Cupressus funebris leaves was 132.79 in December and decreased to 84.91 in April of the following year, and Cinnamomum septentrionale had an average annual C:N of 52.6. A low C:N reflects rapid growth of the silver wood in the early stages of tree growth. (2) N:P of cypress and Cinnamomum septentrionale leaves were 10.77 and 10.64 respectively, which were obviously below the threshold of N limitation. The growth of both plants was mainly limited by N. (3) The silver wood litter increased and N:C and N:P decreased, while the correlation between soil nutrient elements and corresponding plant leaves and litter increased. The introduction of the broadleaf species was favorable to trigger the forest soil nutrient recycling process.





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