【摘要】：本研究樣地位于福建大武夷山常綠闊葉林野外定位觀測站三明觀測點(diǎn)米櫧天然林,通過設(shè)置隔離30%降雨(T1)、隔離60%降雨(T2)以及沒有隔離降雨的對照(CK),進(jìn)行定位研究。著重從土壤微生物群落結(jié)構(gòu)變化的角度,探討隔離降雨對米櫧天然林土壤呼吸的影響。通過室內(nèi)設(shè)置10%WHC(Water Holding Capacity,土壤持水量)、30%WHC、60%WHC、80%WHC土壤含水量試驗(yàn),以及30%WHC-80%WHC干濕交替試驗(yàn),揭示含水量變化對土壤有機(jī)碳礦化的內(nèi)在機(jī)理,為闡明隔離降雨對土壤呼吸的影響提供有利的補(bǔ)充說明。結(jié)果表明：(1)不同程度隔離降雨土壤呼吸的月動態(tài)變化基本一致,土壤呼吸的年平均速率表現(xiàn)為T2T1CK,但三個處理之間土壤呼吸速率及土壤呼吸年通量差異均不顯著。(2)隔離降雨對土壤微生物群落的影響主要集中于0-10 cm土層,對10-20 cm土層微生物生物量和群落結(jié)構(gòu)均無較大影響。主成分分析表明,2013年11月0-10 cm土層中,隔離30%降雨水平土壤微生物群落,與隔離60%降雨水平及對照的微生物群落存在較大差異,而2014年4月和2014年9月,0-10cm三個處理間土壤微生物群落差異不大。對0-10 cm土層的17種磷脂脂肪酸進(jìn)行因子分析發(fā)現(xiàn),隔離降雨對土壤微生物群落影響大小表現(xiàn)為,革蘭氏陽性菌放線菌叢枝菌根真菌革蘭氏陰性菌真菌。(3)室內(nèi)模擬試驗(yàn)表明,土壤有機(jī)碳累積礦化量隨著土壤含水量的增加而增加,4個水分處理水平均對土壤革蘭氏陽性菌產(chǎn)生較大影響。干濕交替濕潤期C02累積量明顯高于干旱期C02累積量,并且隨著交替次數(shù)的增加,CO2累積值大小差異越明顯。因子分析表明干濕交替對土壤放線菌和革蘭氏陽性菌的影響較大,而對土壤叢枝菌根真菌、革蘭氏陰性菌和土壤真菌的影響不大。
[Abstract]:The sample land was located in Sanming natural forest of Sanming observation site of evergreen broadleaved forest in Dawyishan, Fujian Province. The location was studied by setting up isolation of 30% rainfall (T1), 60% rainfall (T2) and CK without isolated rainfall. The effect of rainfall isolation on soil respiration in Castanopsis carlesii natural forest was studied from the point of view of soil microbial community structure change. By setting up 10WHC (Water holding capacity), 30 WHC-80WHC soil moisture test, and 30WHC-80WHC dry and wet alternating test, the inherent mechanism of soil organic carbon mineralization caused by water content change is revealed. It provides a favorable supplementary explanation to clarify the effect of rainfall isolation on soil respiration. The results show that: (1) the monthly dynamic changes of rainfall soil respiration in different degrees are basically the same; The annual average rate of soil respiration was T _ 2T _ 1 CK, but there was no significant difference in soil respiration rate and soil respiration flux among the three treatments. (2) the effect of rainfall isolation on soil microbial community was mainly concentrated in 0-10 cm soil layer. There was no significant effect on microbial biomass and community structure in 10-20 cm soil layer. Principal component analysis (PCA) showed that the soil microbial communities isolated at 30% rainfall level in 0-10 cm soil layer in November 2013 were significantly different from those in 60% rainfall isolation level and control. However, there was no significant difference in soil microbial communities between April 2014 and September 2014. By factor analysis of 17 phospholipid fatty acids in 0-10 cm soil layer, it was found that the effect of isolated rainfall on soil microbial community was as follows: Gram-positive actinomycetes, arbuscular mycorrhizal fungi, gram-negative fungi. The accumulation and mineralization of soil organic carbon increased with the increase of soil water content, and all the four water treatments had a great effect on Gram-positive bacteria in soil. The accumulation of CO2 in dry and wet alternate wetting period was significantly higher than that in drought period, and the difference of CO2 accumulation value was more obvious with the increase of alternating times. Factor analysis showed that dry and wet alternation had a great effect on soil actinomycetes and Gram-positive bacteria, but had little effect on soil arbuscular mycorrhizal fungi, Gram-negative fungi and soil fungi.
【學(xué)位授予單位】：福建師范大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2015
【分類號】：S714.3

【參考文獻(xiàn)】

相關(guān)期刊論文 前2條

1 嚴(yán)俊霞;李洪建;尤龍鳳;;玉米農(nóng)田土壤呼吸與環(huán)境因子的關(guān)系研究[J];干旱區(qū)資源與環(huán)境;2010年03期

2 孫良杰;齊玉春;董云社;彭琴;何亞婷;劉欣超;賈軍強(qiáng);曹叢叢;;全球變化對草地土壤微生物群落多樣性的影響研究進(jìn)展[J];地理科學(xué)進(jìn)展;2012年12期

，

本文編號：2121924