發(fā)布時間：2019-03-04 08:15

【摘要】：土壤微生物是草原土壤生態(tài)系統(tǒng)的重要組成部分。為研究氮沉降增加對草原土壤微生物群落結(jié)構(gòu)的影響,以內(nèi)蒙古貝加爾針茅草原為研究對象,開展連續(xù)6年(2010—2015年)模擬氮沉降試驗(yàn),以N計算,設(shè)置:N0(0 kg·hm~(-2))、N50(50kg·hm~(-2))、N100(100 kg·hm~(-2))、N150(150 kg·hm~(-2))和N300(300 kg·hm~(-2))5個處理,采用磷脂脂肪酸(PLFA)技術(shù)測定0~10 cm土壤特征微生物PLFA生物標(biāo)記數(shù)量并探討土壤微生物群落結(jié)構(gòu)對氮沉降的響應(yīng)。結(jié)果表明:隨氮添加量增大,土壤微生物總PLFAs、細(xì)菌PLFAs、革蘭氏陽性細(xì)菌PLFAs、革蘭氏陰性細(xì)菌PLFAs和放線菌PLFAs含量呈先升高后降低的趨勢,均以N100(100 kg·hm~(-2))處理最高。土壤微生物群落PLFA標(biāo)記的主成分分析顯示,不同氮添加下土壤微生物PLFA標(biāo)記有顯著差異。相關(guān)分析表明,土壤革蘭氏陽性菌、放線菌PLFA含量、G~+/G~-與土壤p H值呈顯著負(fù)相關(guān),土壤微生物總PLFAs、土壤細(xì)菌PLFAs、革蘭氏陽性菌PLFAs、革蘭氏陰性菌PLFAs、放線菌PLFAs和飽和脂肪酸PLFAs含量均與土壤速效磷含量呈顯著正相關(guān)。綜合研究表明,連續(xù)6年氮添加改變了貝加爾針茅草原土壤微生物群落結(jié)構(gòu),土壤p H值和土壤速效磷含量是驅(qū)動這種變化的主要因素。
[Abstract]:Soil microorganism is an important part of grassland soil ecosystem. In order to study the effect of nitrogen deposition on soil microbial community structure in steppe, the experiment of simulated nitrogen deposition in Stipa Baikal grassland in Inner Mongolia for 6 consecutive years (2010-2015) was carried out, calculated by N, and the effect of nitrogen deposition on soil microbial community structure was studied. Set: N0 (0 kg 路hm ~ (- 2), N _ 50 (50kg 路hm ~ (- 2), N _ 100) and N _ 300 (300 kg 路hm ~ (- 2) five treatments, N0 (0 kg 路hm ~ (- 2), N150 (150 kg 路hm ~ (- 2) and N300 (300 kg 路hm ~ (- 2). Phospholipid fatty acid (PLFA) technique was used to determine the number of microbial PLFA biomarkers in 0 ~ 10 cm soil and to investigate the response of soil microbial community structure to nitrogen deposition. The results showed that the contents of total PLFAs, bacteria PLFAs, Gram-positive bacteria PLFAs, Gram-negative bacteria PLFAs and actinomycetes PLFAs increased at first and then decreased with the increase of nitrogen content. The treatment of N 100 (100 kg 路hm ~ (- 2) was the highest. Principal component analysis (PCA) of PLFA markers in soil microbial communities showed that there were significant differences in soil microbial PLFA markers under different nitrogen additions. The correlation analysis showed that the contents of Gram positive bacteria and actinomycetes PLFA in soil were negatively correlated with the pH value of soil, and the total PLFAs, bacteria in soil were PLFAs, Gram positive bacteria PLFAs, Gram negative bacteria PLFAs,. The content of actinomycetes PLFAs and saturated fatty acid PLFAs were positively correlated with the content of available phosphorus in soil. The results showed that the soil microbial community structure was changed by nitrogen addition for 6 years. The pH value of soil and the content of available phosphorus in soil were the main factors driving this change.
【作者單位】： 農(nóng)業(yè)部環(huán)境保護(hù)科研監(jiān)測所;
【基金】：國家自然科學(xué)基金項(xiàng)目(31170435)
【分類號】：S812.2

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