CAJ | 학술논문

祁连山冻土区是我国青藏高原重要永久冻土区之一，也是我国陆域天然气水合物分布的重要地区。前期调查表明祁连山木里天然气水合物钻井区一带具有丰富多样的高寒冻土生态类型。为了解该地区高寒草甸和高寒沼泽草甸表层土壤中古菌群落的多样性及分布特征，对2014年初冬在该区采集的表层土壤样品利用16S rRNA 分子生物学技术和地球化学等方法进行了分析和研究。结果显示，高寒草甸区土壤呈中性，而高寒沼泽草甸区土壤呈弱酸性。钻井区土壤中的 TOC 和顶空气甲烷含量均显著高于背景区，而在背景区内的两种生态类型土壤中的 TOC 和顶空气甲烷含量差别较小。钻井区（除1个点）微生物细胞丰度高于背景区2～5倍。冬季表层土壤中的古菌多样性较低，含泉古菌的3个类群和广古菌的3个类群。不同植被类型古菌群落的优势种群显著不同，在高寒草甸区为泉古菌门的 Group Ⅰ.1b，而高寒沼泽草甸区为广古菌门的甲烷八叠球菌目（Methanosarcinales）。根据研究结果推测，土壤水分可能是导致高寒草甸区和高寒沼泽草甸区细胞丰度和古菌群落差异的一个主要原因，高寒沼泽草甸区内产甲烷菌占优势可能与土壤高 TOC 含量有关。高寒沼泽草甸土壤中存在较丰富的产甲烷古菌，它们在厌氧条件下的甲烷氧化作用也是土壤中甲烷来源之一。
기련산동토구시아국청장고원중요영구동토구지일，야시아국륙역천연기수합물분포적중요지구。전기조사표명기련산목리천연기수합물찬정구일대구유봉부다양적고한동토생태류형。위료해해지구고한초전화고한소택초전표층토양중고균군락적다양성급분포특정，대2014년초동재해구채집적표층토양양품이용16S rRNA 분자생물학기술화지구화학등방법진행료분석화연구。결과현시，고한초전구토양정중성，이고한소택초전구토양정약산성。찬정구토양중적 TOC 화정공기갑완함량균현저고우배경구，이재배경구내적량충생태류형토양중적 TOC 화정공기갑완함량차별교소。찬정구（제1개점）미생물세포봉도고우배경구2～5배。동계표층토양중적고균다양성교저，함천고균적3개류군화엄고균적3개류군。불동식피류형고균군락적우세충군현저불동，재고한초전구위천고균문적 Group Ⅰ.1b，이고한소택초전구위엄고균문적갑완팔첩구균목（Methanosarcinales）。근거연구결과추측，토양수분가능시도치고한초전구화고한소택초전구세포봉도화고균군락차이적일개주요원인，고한소택초전구내산갑완균점우세가능여토양고 TOC 함량유관。고한소택초전토양중존재교봉부적산갑완고균，타문재염양조건하적갑완양화작용야시토양중갑완래원지일。
Qilian Mountain Permafrost,located in the north of Tibet Plateau,is one of the most important per-mafrost regions,and it is also known as an important area for gas hydrate distribution on land in China.Previous studies showed that two main types of alpine ecosystems,including alpine meadow and alpine swamp meadow, were observed around the gas hydrate drilling area.In order to insight into the archaeal community and its distri-bution in the both topsoils of alpine ecosystem,the geochemical parameters and archaeal community composi-tions were analyzed for the soil samples collected during the early winter of 2014.The results showed that pH of the soils from alpine meadow were neutral,whereas pH of the soils from alpine swamp meadow were slightly acidic.The TOC content and methane concentration in the soils of the drilling area were significantly higher than those in the background area (non-hydrate drilling area),however,they were shown no difference when compared with those in different topsoils of alpine ecosystems in background area.The microbial cell abundance in the drilling area (except for DZ2-14Q-5T sample)was 2 to 5 folds higher than that in the background area. The archaeal biodiversity was poor in the winter seasonal topsoils,and was comprised of three archaeal groups affiliated to Crenarchaeota and three groups affiliated to Eurarchaeota.The archaeal communities from alpine meadow topsoils were dominated by Group Ⅰ.1b affiliated to Crenarchaeota,while alpine swamp meadow top-soils were dominated by Methanosarcinales affiliated to Eurarchaeota.It was inferred that the moisture in top-soils may be one of the most important reasons causing the variation of microbial cell abundances and the differ-ent compositions of archaeal communities between the both topsoils of alpine ecosystem,and the methanogenic archaea dominated in the alpine swap meadow soils was more related to the higher TOC content.The results also showed that more abundance of methanogenic archaea inhabited in the alpine swamp meadow topsoils than that in the alpine meadow topsoils.It was well known that the methanogens oxidized the organic carbon to produce methane under anaerobic conditions,contributing of one source of soil methane from biogenesis.