水分梯度变化对环湖地区天然牧草发育期及生物量的影响

THE EFFECT OF WATER GRADIENT CHANGE ON THE GROWTH AND BIOMASS OF NATURAL HERBAGE IN THE HUANHU AREA

在牧草生长季节历年每旬降水量的基础上分别增加25%(试验当年降水量+比历年同期增加25%的水量)、50%、60%、70%、75%、0%6个量级,通过与历年观测数据对比研究水分对草地上生物量影响,揭示不同水分增加条件下牧草发育期和生物量的变化情况,以及高寒草原牧草的发育状况、生物量与水分的关系。结果表明:对于不同种类的牧草,各阶段不同灌水处理间,主要优势种牧草对总产量的贡献率,6至7月变化不大,期间冷地早熟禾、矮生嵩草、扁蓿豆贡献率较大,但8月份对牧草总产量的贡献率变为西北针茅等禾本科牧草;随着水分的增加生物量随之发生了变化,扁蓿豆明显增加;且各牧草发育期也发生了变化。

In the growing season of pasture,on the basis of the precipitation in previous years,the precipitation in every ten days increased by 25%,50%,60%,70%,75% and 0% respectively(the precipitation in the experimental year + 25% more water than that in the same period in previous years).By comparing the effects of water on Grassland Biomass in the observed data over the years,this paper reveals the development period and biomass changes of grassland under different water increasing conditions,and the relationship between grassland development status,biomass and water in alpine grassland.The results showed that for different kinds of forage,the contribution rate of the main dominant species of forage to the total yield changed little from June to July,while the contribution rate of cold bluegrass,kobresia humilis and alfalfa beans was higher during the period,but the contribution rate of August to the total yield of forage changed to the grasses such as Stipa northwest;With the increase of water,the biomass changed accordingly.With the change of water,the development stages of pasture also changed.