关键词: 冻融循环, 矿化速率, 硝态氮, 雪被去除, 铵态氮, 硝化速率

Abstract: Standard of regional eco-compensation (REC) is one of the key issues to establish REC mechanism. Land use/cover data were acquired by using Landsat remote sensing images. From a geographical view of scale relevance and scale transition, this study put forward ecological compensation urgent index (ECUI) and the model of eco-compensation standard based on ecological value equivalents by taking both the ecosystem service value and the economic development level of different regions into consideration. The ecosystem service value, ECUI and REC standard of Gansu Province in 2011 were calculated and the spatial disparities were analyzed at three spatial scales: ecological zone scale, prefecture-level city scale and county scale. The results showed that Gannan Plateau, Hexi mountain and desert ecological zone should have priority to get compensation, and the urban ecological zone along the Yellow River should first provide compensation. The municipal districts and mining counties had the lowest priority level among all the counties of Gansu. Among all the 87 counties, Akesai, Subei, Maqu and Sunan were high in ecological output, which had the highest level of priority to get compensation. At the prefecture-level, REC values in Jiayuguan, Lanzhou and Pingliang were negative and they should pay REC while REC values in Jiuquan, Gannan and Zhangye are positive and they should receive REC.

Key words: nitrate, freeze-thaw cycle, mineralization rate, snow removal, ammonium, nitrification rate