林冠受损对南岭森林土壤固碳微生物的影响

发布时间：2018-01-17 18:32

本文关键词：林冠受损对南岭森林土壤固碳微生物的影响　出处：《中国林业科学研究院》2017年硕士论文　论文类型：学位论文

【摘要】：土壤固碳微生物是森林土壤碳循环中重要的组成部分,它们的变化直接影响土壤的固碳效率。本论文在模拟冰灾、台风等对林冠造成损伤的实验样地,采集土样并提取土壤DNA,利用Miseq高通量测序技术对土壤固碳微生物功能基因cbbL进行测序,旨在了解森林受损对土壤固碳微生物多样性及其群落结构的影响以及此后的生态恢复过程中土壤固碳微生物群落的变化规律,探讨森林土壤固碳微生物对林冠受损的响应,为研究森林土壤固碳微生物固碳潜力提供理论依据。本实验结果如下:(1)林冠开度和凋落物输入量对土壤固碳微生物菌群有显著性影响。森林林冠受损1年后,土壤固碳微生物种群数量明显降低、多样性增加;受损2年后,其种群数量、多样性均低于对照;表明森林林冠受损,降低了土壤固碳微生物种群数量,短期内提高其多样性水平。随着受损森林的恢复,微生物之间的相互竞争,其多样性水平明显下降;林冠受损4-5年后,其林冠开度、凋落物输入量、土壤固碳微生物的种群数量、多样性水平、群落结构组成与对照差异较小,表明森林生态系统已经基本恢复到受损前水平,说明受损森林通过4-5年即可恢复。(2)森林受损前期,林冠损伤+保留枝叶(TD)要比林冠损伤+移除枝叶(TR)和未损伤+移入枝叶(UD)的单一处理对土壤固碳微生物的影响要大,但随着受损森林的恢复,TD处理比TR和UD处理与对照水平更接近,表明在受损森林生态系统恢复过程中,林冠损伤和凋落物输入双重处理要比单一处理更易于恢复。(3)2013年土壤固碳微生物的种群数量、多样性指标均明显低于其它年份,相关性分析研究显示其与降雨直接相关,2013年降雨过多降低了固碳微生物的种群数量和多样性水平,对其群落结构产生明显的影响,一些主要类群数量变化明显,亚硝化螺菌属数量下降,而糖单孢菌属和Ideonella属则有较大幅度的上升。表明降雨对土壤固碳微生物种群数量、多样性、群落结构会产生较大的影响。(4)林冠开度、凋落物输入量与土壤固碳微生物种群数量、多样性、菌群组成存在正相关或负相关,其中的一些存在显著或极显著相关;也与土壤pH值、有机碳、全氮、全磷、有效磷、硝态氮等化学性质明显相关;而土壤的化学成分也与固碳微生物种群数量、多样性、物种组成存在相关性,表明森林生态系统中,林木、凋落物、土壤、微生物等各生态因子是密切相关的,土壤固碳微生物群落结构受周围生物、非生物因子的影响。(5)森林土壤固碳微生物在门水平上可以分到5个门,即放线菌门、变形菌门、蓝藻门、绿弯菌门和厚壁菌门;变形菌门和放线菌门为优势菌群,它们的含量占土壤固碳微生物总数的98.54%;菌群可以分类到59个属,在属水平上,菌群含量超过5%的菌群有亚硝化螺菌属、链霉菌、糖单孢菌属、分枝杆菌属、诺卡氏菌属、慢生根瘤菌属,菌群含量在1%-5%的菌群有Ideonella属、斯塔普氏菌属、副伯克氏菌属、产碱杆菌科某属、慢生型根瘤菌科某属、伯克氏菌属、Methyloferula属、红长命菌属、高温单孢菌属、假诺卡氏菌科某属、黄色杆菌属、Hydrocarboniphaga属、拟甲色球藻属、Caballeronia属。
[Abstract]:Carbon sequestration of soil microorganism is an important component of forest soil carbon cycle, carbon sequestration efficiency changes directly affect the soil. In this paper, simulation of the ice disaster, typhoon damage experimental plots on the canopy, soil samples and soil DNA extraction, sequencing of soil microbial carbon sequestration function of cbbL gene by Miseq high throughput sequencing technology, in order to understand the damage of forest carbon sequestration in soil microbial diversity and community structure and the influence of the ecological restoration process of carbon sequestration in soil microbial community changes on forest carbon sequestration in soil microbial response to canopy damage, and provide a theoretical basis for the research of forest carbon sequestration in soil microbial carbon sequestration potential. The results are as follows: (1) canopy openness and litter input on carbon sequestration in soil microorganisms have significant influence. The forest canopy damage after 1 years, carbon sequestration of soil microorganism The population decreased obviously, diversity increased; 2 years after the damage, the population number, diversity was lower than the control; showed that the forest canopy damage, reduce the carbon sequestration in soil microbial population, improve the diversity level in the short term. With the restoration of forests damaged, competition between microorganisms, the diversity level obviously drop; canopy damage 4-5 years after the opening of the canopy, litter input, carbon sequestration in soil microbial population, diversity, community structure and control the difference is small, showed that the forest ecosystem has been restored to the level before the basic damage, indicating the damage of forest can be restored through 4-5 (2) forest. The early damage, injury and retaining canopy (TD) leaves than canopy damage and removal leaves (TR) and non injury + into leaves (UD) single treatment effects on soil carbon sequestration of microorganisms to be big, but with the recovery of damaged forest, TD Under TR and UD treatments and the control level closer to that in the recovery process of damaged forest ecosystem, canopy damage and litter input double treatment to more easily recover than single treatment. (3 2013) carbon sequestration in soil microbial population and diversity index were significantly lower than the other years, correlation analysis showed that the direct correlation with rainfall in 2013, excessive rainfall decrease the solid population and diversity of microbial carbon levels have obvious influence on the community structure, changes in the number of major groups obviously, nitrosospira number decreased, while saccharomonospora and Ideonella has increased greatly. It showed that rainfall of carbon sequestration in soil microbial population, diversity, community structure will have a greater impact. (4) canopy openness, litter input and carbon sequestration in soil microbial population, diversity, flora composition. In a positive or negative correlation, some of which have significant or extremely significant correlation; and soil pH value, organic carbon, total nitrogen, total phosphorus, available phosphorus, nitrate nitrogen was significantly related to chemical properties; and the chemical composition of the soil and carbon sequestration and microbial population, diversity, species composition correlated. Show that the forest ecological system, forest, litter, soil microorganism, various ecological factors are closely related, carbon sequestration in soil microbial community structure by the surrounding biological effects of abiotic factors. (5) the forest carbon sequestration in soil microorganisms at the gate level can be divided into 5, namely Actinobacteria, cyanobacteria, Proteobacteria, Chloroflexi and Firmicutes; Proteobacteria and actinobacteria were dominant bacteria, their content accounted for 98.54% of the total soil carbon sequestration and microbial flora; can be classified into 59 genera, at the genus level, more than 5% of the content of bacteria flora there are Yaxiaohualuo Sp., Streptomyces, saccharomonospora, Mycobacterium, Nocardia, Bradyrhizobium, flora in genus Ideonella in 1%-5% flora, Starr P. Copri, deputy Burkholderia genus Alcaligenes, a genus of slow growing Rhizobium, a genus Burkholderia. Genus Methyloferula, genus Rubrivivax, Thermomonospora, false nocardiaceae is a yellow, bacillus, Hydrocarboniphaga, a quasi chroococcus genus, the genus Caballeronia.

【学位授予单位】：中国林业科学研究院
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S714.3

【参考文献】