模拟增温和添加氮素对高寒草甸草地生产力影响的初步研究

为探索高寒草地植被对模拟增温和添加氮素的响应机制,通过在野外对高寒草甸进行模拟增温和硝态氮、铵态氮的氮素添加试验,研究模拟增温和添加氮素对高寒草地群落物种组成、生产力及土壤水含量的影响.结果表明:增温和添加氮素可显著增加植物地上总生物量、优良牧草地上生物量和植被平均高度(P <0.05).增温处理能增加植物种类,且有利于杂类草生物量的增加;对几种主要植物来说,增温施氮互作下植株高度高于其他处理,土壤0～15和15～30 cm水分均先减少后增加,且都为不增温不施肥处理最高.可见增温施氮互作处理能够促进植被的生长,但不利于土壤水分的增加.

The Impacts of Simulative Warming and Adding Nitrogen on the Grassland Productivity of Alpine Meadow

To explore the response mechanism of the alpine meadow vegetation to simulative warming and adding nitrogen, the influences of simulative warming and adding nitrogen on the community species composition, productivity, and soil water content of alpine meadow were investigated under field conditions. The results showed that warming and adding nitrogen could significantly increase the total aboveground biomass of plant, the aboveground biomass of fine pastures and the average height of vegetation (P <0.05). Warming treatment was beneficial to the increases of plant species and weed biomass. For several main plants, the plant height of both warming and adding nitrogen treatment was higher than other treatments. Soil moisture decreased first, and then increased under both 0~15 and 15~30 cm. The soil moisture content of without warming and non-nitrogen addition treatment reached the highest predicting that both warming and adding nitrogen treatment could promote the growth of vegetation, but not conducive to the increase of soil moisture content.