开垦对荒漠土壤微生物群落结构特征的影响

发布时间：2019-01-21 11:58

【摘要】：以古尔班通古特沙漠南缘典型流域(玛纳斯河、吉木萨尔河、三工河、四工河、水磨河)的绿洲农田与毗邻荒漠土壤为研究对象,采用磷脂脂肪酸(PLFA)方法分析不同开垦年限的土壤微生物生物量、群落结构、多样性变化特征。结果表明:荒漠开垦后,土壤微生物总PLFA含量、真菌PLFA、细菌PLFA、革兰氏阳性菌(G~+)和革兰氏阴性菌(G-)PLFA含量均显著增加。荒漠开垦5 a内,细菌PLFA与G-PLFA增长更强烈,使得真菌PLFA/细菌PLFA比值降低了48%,G~+PLFA/G-PLFA比值(革兰氏阳性菌与革兰氏阴性菌的PLFA比值)降低了67%。但随着开垦年限的延长,这两个比值没有显著变化,表明与开垦年限相比,荒漠的开垦行为对土壤微生物群落结构有着更加强烈的影响。随着开垦年限的增加,土壤微生物群落多样性总体呈上升趋势。虽然荒漠在开垦50 a后多样性指数略有下降,但仍远高于荒漠土壤。土壤微生物总PLFA含量和大部分菌群PLFA含量与土壤电导率显著负相关,与全氮和有机碳显著正相关。荒漠在开垦过程中灌溉增加了土壤水分且降低了土壤盐分,全氮和有机碳含量增加,这些改变是土壤微生物群落变化的主要原因。荒漠开垦有助于提高土壤微生物PLFA含量、改善土壤微生物的群落结构、丰富土壤微生物群落多样性,有利于土壤质量的提高。
[Abstract]:The oasis farmland and adjacent desert soil in the typical watershed (Manas River, Jimusar River, Sangong River, Simo River) in the southern margin of Guerbantungute Desert were studied. The changes of soil microbial biomass, community structure and diversity in different reclamation years were analyzed by phospholipid fatty acid (PLFA) method. The results showed that the total PLFA content of soil microorganism, the content of PLFA, Gram-positive bacteria (G-) and G- PLFA of fungal PLFA, bacteria increased significantly after desert reclamation. During 5 years of desert reclamation, the increase of bacterial PLFA and G-PLFA was stronger, which reduced the PLFA ratio of fungal PLFA/ bacteria to 48% G ~ PLFA/G-PLFA ratio (PLFA ratio of Gram-positive bacteria and Gram-negative bacteria) decreased 67%. However, with the extension of reclamation years, these two ratios did not change significantly, which indicated that the reclaimed behavior of desert had a stronger effect on the soil microbial community structure than that of reclamation years. The diversity of soil microbial communities increased with the increase of reclamation years. Although the diversity index of desert decreased slightly after 50 years of reclamation, it was still much higher than desert soil. The total PLFA content of soil microorganism and the PLFA content of most microflora were negatively correlated with soil conductivity, but positively correlated with total nitrogen and organic carbon. During the process of desert reclamation, irrigation increased soil moisture, decreased soil salinity, and increased total nitrogen and organic carbon content, which were the main reasons for the change of soil microbial community. Desert reclamation can improve the PLFA content of soil microorganisms, improve the community structure of soil microorganisms, enrich the diversity of soil microbial communities, and improve soil quality.
【作者单位】：中国科学院新疆生态与地理研究所荒漠与绿洲国家重点实验室;中国科学院大学;中国科学院新疆生态与地理研究所阜康荒漠生态系统国家站;
【基金】：国家自然科学基金项目(41671114,41301102)
【分类号】：S154.3

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