CAJ | 학술논문

对三江源区不同退化演替阶段的高寒草甸土壤酶活性和微生物群落结构进行分析，结果表明：1）土壤微生物种类和数量并不随着高寒草甸的退化而降低，而是在中度退化阶段达到最高；2）不同退化演替过程，中度退化阶段土壤微生物的结构更加复杂；3）不同土层中，0～10 cm土壤微生物的多样性更加丰富，其群落结构能更好地适应外界环境的变化；4）5种土壤酶的酶活性均随土层深度的增加而显著降低（P＜0．05）。在不同退化演替阶段，碱性磷酸酶的活性随演替的进行而显著降低（P＜0．05）；蛋白酶和多酚氧化酶的酶活性最大值出现在中度退化演替阶段，最小值则在未退化阶段（原生植被）出现；蔗糖酶和脲酶活性在4个演替阶段中均无显著变化（P＞0．05）。不同酶活性对外界环境变化敏感性不同，蛋白酶、碱性磷酸酶和多酚氧化酶具有较高的敏感性，而脲酶和蔗糖酶活性的敏感性较低；5）土壤酶活性与土壤微生物在高寒草甸不同退化演替阶段具有显著相关性（P＜0．05）。土壤酶活性、土壤微生物群落结构可以作为一个综合指标，来指示三江源区高寒草甸的演替阶段和退化程度。
대삼강원구불동퇴화연체계단적고한초전토양매활성화미생물군락결구진행분석，결과표명：1）토양미생물충류화수량병불수착고한초전적퇴화이강저，이시재중도퇴화계단체도최고；2）불동퇴화연체과정，중도퇴화계단토양미생물적결구경가복잡；3）불동토층중，0～10 cm토양미생물적다양성경가봉부，기군락결구능경호지괄응외계배경적변화；4）5충토양매적매활성균수토층심도적증가이현저강저（P＜0．05）。재불동퇴화연체계단，감성린산매적활성수연체적진행이현저강저（P＜0．05）；단백매화다분양화매적매활성최대치출현재중도퇴화연체계단，최소치칙재미퇴화계단（원생식피）출현；자당매화뇨매활성재4개연체계단중균무현저변화（P＞0．05）。불동매활성대외계배경변화민감성불동，단백매、감성린산매화다분양화매구유교고적민감성，이뇨매화자당매활성적민감성교저；5）토양매활성여토양미생물재고한초전불동퇴화연체계단구유현저상관성（P＜0．05）。토양매활성、토양미생물군락결구가이작위일개종합지표，래지시삼강원구고한초전적연체계단화퇴화정도。
An analysis was carried out on the soil enzyme activities and the soil microbial community structure of alpine meadows in the headwater area of the Yellow River,the Yangtze River and the Lancang River at four successional degraded stages (NS:Normal Steppe,LD:Light Degradation,MD:Moderate Degradation,HD:Heavy Degradation)using the colorimetric method and phospholipids fatty acid (PLFA).1)The species and quantity of soil microbes did not reduce with degradation of the alpine meadow and they reached the highest lev-el at MD.2)The soil microbial structure at MD was the most complex one among the four stages.3)The soil microbial diversity in the 0-10 cm layer was richer than that at 10-20 cm,which made the microbial commu-nity structure better adapted to the changes of ambient environment.4)The activities of all five enzymes de-creased significantly (P<0.05)with soil depth and the activity of alkali phosphatase decreased considerably as the alpine meadow degraded (P<0.05).The maximum activities of protease and polyphenol oxidase appeared at MD,with the minimum in NS,but the activities of invertase and urease (P>0.05)seldom changed in any of the four stages.Enzyme activities responded differently to changes of the ambient environment.Alkali phos-phatase,protease and polyphenol were more sensitive than invertase and urease.5 )There was a significant correlation between soil enzyme activities and soil microbes at successional degraded stages of the alpine mead-ow (P<0.05).Soil enzyme activities and soil microbial community structure could be comprehensive indica-tors to show the stage of succession and the degree of degradation on the alpine meadows in the headwater areas of the three rivers.