【摘要】 使用氯仿熏蒸浸提法对东祁连山高寒草甸土壤微生物量进行了研究,结果表明,微生物量碳(646.32~1 132.05μg/g)、氮(31.46~100.57μg/g)和磷(13.00~51.62μg/g)均为上层高于下层,其对土壤有机质、全氮和全磷的贡献率分别为0.45%~0.84%,0.65%~1.30%和0.54%~3.39%;微生物量碳、氮、磷彼此间呈显著正相关(P<0.01);微生物量与含水量和土壤容重在杜鹃、珠芽蓼和禾草草地呈显著负相关(P<0.01),与pH值在金露梅灌丛(P<0.01)、珠芽蓼草地(P<0.05)和嵩草草地(P<0.01)呈显著负相关,在杜鹃(P<0.01)和高山柳灌丛(P<0.05)呈显著正相关。微生物量碳氮比及碳磷比分别为9.59~24.95和17.13~91.65。土壤微生物量碳氮比和微生物量碳对土壤有机质的贡献率可反映草地土壤营养状况。更多还原

【Abstract】 In July,2005,the soil microbial biomass and soil physical-chemical properties were studied under six sites(Rhododendron simsii brushland,Salix cupularis brushland,Potentilla fruticosa brushland,Polygonum viviparum grassland,Grass steppe and Kobresia capillifolia grassland)in alpine grassland of the eastern Qilian Mountains under Qinghai-Tibetan Plateau,west of China,which aimed to assess the difference from other ecosystems on microbial biomass and correlation between microbial biomass and physical properties and discuss the indicator of grassland quality by microbial biomass.The microbial biomass carbon(MBC),nitrogen(MBN) and phosphorus(MBP) ranged from 646.32 to 1 132.05,31.46 to 100.57 and 13.00 to 51.62 μg/g,respectively.Furthermore,the microbial biomass at the upper layer was higher than those at the lower layer and showed positive correlation with each other.Under R.simsii brushland,P.viviparum grasslnd and grass steppe,the MBC,MBN and MBP showed significant negative correlation with the soil water content and bulk density.The microbial biomass also showed significant positive correlation with pH under R.simsii brushland and S.cupularis brushland,however,significant negative correlation with pH under P.fruticosa brushland,P.viviparum grassland and K.capillifolia grassland.The contribution of MBC,MBN and MBP to soil organic matter,total nitrogen and total phosphorus varied from 0.45% to 0.84%,0.65% to 1.30% and 0.54% to 3.39%,respectively.The microbial biomass C∶N ratios ranged from 9.59 to 24.95 and the microbial biomass C∶P ratios from 17.13 to 91.65.The results also showed that the MBC∶MBN and the contribution ratios of MBC to soil organic matter may be taken as an indicator of grassland quality.更多还原