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亚高山森林凋落叶腐殖化是联系植物与土壤碳库和养分库的重要通道,在冬季可能受到雪被斑块的影响。该文采用凋落物网袋法,于2012年11月–2013年4月研究了川西亚高山森林不同厚度雪被斑块(厚雪被、中雪被、薄雪被和无雪被)下优势树种岷江冷杉(Abies faxoniana)、方枝柏(Sabina saltuaria)、四川红杉(Larix mastersiana)、红桦(Betula albo-sinensis)、康定柳(Salix paraplesia)和高山杜鹃(Rhododendron lapponicum)凋落叶在不同雪被关键期(雪被形成期、雪被覆盖期和雪被融化期)的腐殖化特征。结果表明:亚高山森林冬季不同厚度雪被斑块下6种凋落叶均保持一定程度的腐殖化,其中红桦凋落叶腐殖化度最大,达4.45%–5.67%;岷江冷杉、高山杜鹃、康定柳、四川红杉和方枝柏凋落叶腐殖化度分别为1.91%–2.15%、1.14%–2.03%、1.06%–1.97%、0.01%–1.25%和0.39%–1.21%。凋落叶腐殖质在雪被形成期、融化期和整个冬季累积,且累积量随雪被厚度减小而增加,但在雪被覆盖期降解,且降解量随雪被厚度减小而增大。相关分析结果表明,亚高山森林凋落叶前期腐殖化主要受凋落叶质量影响,且与氮和酸不溶性组分呈极显著正相关,而与碳、磷、水溶性和有机溶性组分呈极显著负相关。表明冬季变暖情景下雪被厚度的减小可能促进亚高山森林凋落叶腐殖化,但凋落叶腐殖化在不同雪被关键期受雪被斑块和凋落叶质量的调控。
The decayed leaf humification in subalpine forest is an important channel linking plant and soil carbon pools and nutrient pools and may be affected by plaque in winter. In this paper, the litter net method was used to study the effects of different thicknesses of snow patches (thick snow quilt, middle snow quilt, thin snow quilt and no-snow quilt) in the subalpine forests of western Sichuan in November 2012-April 2013 Species Abies faxoniana, Sabina saltuaria, Larix mastersiana, Betula albo-sinensis, Salix paraplesia and Rhododendron lapponicum litter were different The humus is characterized by key periods (snow formation, snow cover, and snow melting). The results showed that the winter alpine forests with different thicknesses of snow were all humified by 6 kinds of litters under the plaque. The degree of humification of the birch was 4.45% -5.67%, while that of Minjiang fir, alpine azalea , Kangdingliu, Sichuan sequoia and S. japonica were 1.91% -2.15%, 1.14% -2.03%, 1.06% -1.97%, 0.01% -1.25% and 0.39% -1.21%, respectively. Leaf litter humus accumulated in the period of snow formation, thawing and winter, and the cumulant increased with the decrease of snow thickness, but degraded in the cover period of snow and the amount of degradation increased with the decrease of snow thickness. The results of correlation analysis showed that the early humification of the litter in subalpine forest was mainly affected by litter leaf quality, and was positively correlated with nitrogen and acid insoluble components, but with carbon, phosphorus, water-soluble and organic soluble components Significant negative correlation. It is suggested that the decrease of snow thickness in winter may promote the humification of the litter in the subalpine forest. However, the humification of litter is controlled by the quality of patches and litter during the critical period of snow.