生长末期施肥对青藏高原高寒草原地上生物量的影响

为探索青藏高原东北部退化草地的科学恢复途径,以刚察县中度退化的紫花针茅（Stipa Purpurea）高寒草原为研究对象,在生长末期开展“3414”肥料效应实验,研究了不同配比氮、磷、钾施肥方案对退化高寒草原中各功能群生物量与总生物量的影响,建立肥料效应模型,力求寻找使退化草地恢复的最佳施肥比。结果表明：施肥可以提高禾草类、杂草类生物量以及总生物量;禾草类和杂草类生物量随氮肥施量的增加而增加,但是磷肥和钾肥并无此规律性的变化。另外,禾草和杂草作为该退化草地的主要功能群,对草地总生物量的贡献率很大。

Effects of Fertilizer at Later Growth Stage on Above-ground Biomass in the Alpine Steppe of Tibetan Plateau

To explore the scientific ways of degraded grassland restoration in the northeast of Tibetan Plateau, the "3414" fertilizer experiment at the later growth stage of Stipa Purpurea in the moderate degraded Alpine Steppe of Gangcha County was conducted. The effects of N, P and K combinations on functional groups' biomass and above-ground biomass were investigated. A fertilizer response model was established in order to find the best ratio of N, P, and K. The results show that the fertilizer increases the biomass of Gramineae, weed and aboveground. The Gramineae biomass and weed biomass increase with the increase of nitrogen fertilizer, rather than phosphate fertilizer and potash fertilizer. In addition, The Gramineae and weed are the main functional groups in Steppe, and contribute a lot to above-ground biomass. The three-factor model simulated from the "3414"fertilizer experiment will be used to guide practical work.