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利用野外分解袋法对秦岭火地塘林区油松、华山松、华北落叶松、锐齿栎凋落叶的分解速率和养分释放趋势进行研究。结果表明,分解2年后,4种树种凋落叶的干物质残留率在35.6%～58.6%,残留率大小顺序为油松>华山松>华北落叶松>锐齿栎。除油松与华山松凋落叶之间残留率差异不显著外,各树种之间凋落叶分解后的残留率差异显著。在2个试验年度中,4-9月凋落叶分解最快,在其他月份保持较平稳的分解速度,分解前12个月凋落叶失重速度明显大于后12个月,呈明显的季节和阶段性差异。利用Olson模型对凋落叶分解50%和95%所需时间进行估测,结果显示,不同树种所需时间差异显著,其中锐齿栎凋落叶95%被分解所需时间最短,为5.43年,油松最长,为9.87年。凋落叶中N、P元素在分解第1年均表现出富集现象,直至1年后达到一个最高值后,开始释放,C含量则呈现出逐步下降的趋势。导致不同树种凋落叶分解速率及养分释放速率差异主要与不同凋落叶的初始质量和性质有关。
The decomposition rates and nutrient release trends of Pinus tabulaeformis, Pinus armandii, Larix principis-rupprechtii and Dendrolimus kirinhoi in the Huoditang Forest Region in the Qinling Mountains were studied by using field decomposition bags. The results showed that after two years of decomposition, the dry matter residues of litter of four tree species were in the range of 35.6% -58.6%, and the order of the residual rate was Pinus tabulaeformis> Pinus armandii> Larix principis-rupprechtii> Quercus variabilis. The difference of residual rate of litter decomposition between the species was significant except for the difference of the residual rate between the deciduous leaves of Pinus tabulaeformis and Pinus armandii. During the two experimental years, litter leaf decomposed fastest from April to September and remained relatively stable in other months. The weight loss rate of litter in the first 12 months was significantly greater than that in the latter 12 months, showing obvious seasonal and stage difference. Olson model was used to estimate the time required for 50% and 95% litter decomposition. The results showed that the time required for different tree species was significantly different, and the time required for 95% decomposition of sharp-leaf oak was the shortest for 5.43 years The longest pine, was 9.87 years. During the first year of decomposition, enrichment of N and P elements in litter leaves began to release after reaching a maximum one year later, while C content showed a gradual downward trend. The differences of decomposition rate and nutrient release rate of litter leaves of different tree species were mainly related to the initial quality and properties of different litter.