杉木和香樟酸雨酸解底物的分解格局

发布时间：2018-07-27 17:53

【摘要】：采用凋落物分解袋法,选取湘西地区两种人工林优势树种(香樟和杉木)的凋落叶作为分解材料,分析了两种凋落叶经酸解处理后凋落物分解及其微生物活性的变化。结果表明:酸解处理过程会使两种凋落叶损失一定的质量,随着酸解强度的增加质量损失增加,且酸解处理对香樟凋落物质量损失的影响较杉木凋落物大。不同物种凋落物对酸解强度的差异性反应产生了后续分解过程的差异格局:酸雨酸解作用的增强抑制了杉木凋落物分解过程中包括真菌生物量以及纤维素酶与木质素酶在内的微生物活性;而对于香樟凋落物分解过程,微生物活性对酸雨酸解的响应因变量不同、分解期不同而存在差异性。两物种凋落物的总失重率、木质素和纤维素分解率对酸解作用的响应及其在不同分解期的表现也存在差异性:对于杉木凋落物,在分解前期其失重率表现为T1T2T3,而在后期随酸解强度的增大而升高,即T3T2/T1;香樟凋落物在分解的前期(T1T2T3)与后期(T1T2T3)情况则正好与杉木凋落物相反。总之,酸雨酸解凋落物不仅使底物有机组成发生了变化,在一定程度上导致凋落物物理结构紧密程度改变,而且也可能相应地改变了凋落物定殖微生物群落,这些复合影响从不同程度上决定了凋落物分解及其微生物活性对凋落物底物酸解的响应。
[Abstract]:The litter decomposition and microbial activity of two dominant tree species (Cinnamomum camphora and Cunninghamia lanceolata) were analyzed by using litter decomposition bag method. The results showed that the weight loss of the two litters increased with the increase of the acidolysis intensity, and the effect of acidolysis on the litter quality loss was greater than that of Cunninghamia lanceolata (Cunninghamia lanceolata). The different response of litter of different species to acidolysis intensity resulted in a different pattern of subsequent decomposition process: the enhancement of acid rain acid hydrolysis inhibited the fungal biomass, cellulase and wood in the decomposition process of Chinese fir litter. Microbial activity including enzyme; But for the decomposition process of Cinnamomum camphora litter, the response of microbial activity to acid hydrolysis was different, and the decomposition period was different. The total weight loss rate, lignin and cellulose decomposition rate of the two species were also different from each other in different decomposition periods. The weight loss rate of camphora was T1T2T3 at the early stage of decomposition, but increased with the increase of acidolysis intensity at the later stage, that is, T3T2 / T1, and the litter of camphora was opposite to the litter of Chinese fir in the early stage (T1T2T3) and the later stage (T1T2T3). In a word, the acid rain acidolysis litter not only changed the organic composition of the substrate, but also caused the change of the physical structure of litter to a certain extent, and it may also change the litter colonization microbial community accordingly. These complex effects determine the response of litter decomposition and microbial activity to the acid hydrolysis of litter substrate to varying degrees.
【作者单位】：吉首大学生物资源与环境科学学院;吉首大学生态旅游湖南省重点实验室;
【基金】：国家自然科学基金项目(31360135,31560205,41501335) 湖南省战略性新兴产业科技攻关项目(2014GK1062) 生态旅游湖南省重点实验室开放基金项目(JDSTLY1517)
【分类号】：S714;X517

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