长期增温对高寒草甸植物群落和土壤养分的影响

采用国际冻原计划模拟增温效应的方法,研究了连续增温16年后高寒草甸和高寒灌丛的植物群落结构、地上地下生物量、物种多样性、土壤养分含量的响应,以期揭示长期增温对植物群落特征和土壤养分的影响。结果表明:与对照相比,长期增温使高寒草甸植物群落高度增加18.4%,盖度降低5%;灌丛群落高度增加42.8%,盖度增加12.9%。草甸群落地上生物量减少23.6%,0~10,10~20,20~30 cm的地下生物量分别减少22.2%,38.6%,52.1%;灌丛群落地上生物量增加15.1%,0~10,10~20,20~30 cm的地下生物量分别增加4.9%,17.5%,3.1%。草甸群落物种数减少7%,灌丛群落的物种数减少30%。长期增温使草甸和灌丛的土壤速效磷和全磷增加,而全钾降低,其他元素含量变化不一致。长期增温改变了高寒草甸和高寒灌丛的群落结构以及土壤养分含量,但对二者的影响不完全相同。

The Influence of Long-term Simulating Warming to the Plant Community and Soil Nutrient of Alpine Meadow

The responses of plant community structure, aboveground biomass, belowground biomass, species diversity,soil nutrient content of alpine meadow and shrub to the continuous research warming of 16 years were studied by adopting the method of International Tundra Experiment (ITEX) in order to reveal the effects of long-term warming effects on community characteristics and soil nutrients. The results showed that compared with no warming plot, the community height of alpine meadow increased by 18.4%, the coverage reduced by 5%; the community height of alpine shrub increased by 42.8%, the coverage increased by 12.9%, the aboveground biomass of meadow community reduced by 23.6% and that of shrub community increased by 15.1%. The species number of alpine meadow reduced by 7%, while that of shrub reduced by 30%. Simulated warming caused available phosphorus and total phosphorus of meadow and shrub increased, the total potassium decreased, the changes of other nutrient contents were not consistent. Therefore, long-term warming changes the community structure and soil nutrient content of both alpine meadow and alpine shrub, but it is not exactly the same effect.