毛乌素沙地北沙柳人工林生态系统服务及其损益分析

Ecosystem Service and Profit and Loss Analysis of Salix psammophila Plantation in Mu Us Sandy Land

以毛乌素沙地不同林龄的北沙柳人工林为研究对象,在收集、实测不同林龄生态系统服务数据的基础上,分析其变化特征,并通过ESCI指数刻画其损益情况。结果表明:随着林龄的增加,除了速效磷和速效钾先增加后减小外,丰富度指数、Simpson指数、Shannon-Wiener指数、单位面积地上生物量、土壤有机质、全氮和土壤含水量均表现出增加的趋势,防风固沙能力也在增强。随着林龄的增加,生态系统服务增益显著,生物多样性和固碳调节在0~8 a林龄段增益最快,ESCI分别可达8.82和28.50;土壤肥力调节在8~14 a林龄段增益最快;涵养水源在造林初期并没有显著减损;防风固沙在造林初期增益显著,并在造林23 a后防风固沙功能较为稳固。与黑沙蒿群落相比,北沙柳人工林生物多样性和固碳调节在造林8 a后就已经处于增益状态,土壤肥力调节在造林14 a后处于增益状态,所有的功能在造林34 a后均增益。建议今后北沙柳应在该地区人工林营建中继续应用。

Taking Salix psammophila plantation at different ages in Mu Us Sandy Land as the study object, on the basis of collecting and measuring ecosystem service data of different forest ages, the change characteristics of ecosystem service was analyzed, and its profit and loss was described with ESCI index. The results showed that with the increase of forest age, except for available P and available K increased first and then decreased, other indexes showed an increasing trend, and the ability of windbreak and sand fixation was also enhanced. With the increase of forest age, the gain of ecosystem services was significant, and the gains of biodiversity and carbon sequestration were the fastest in the age stage from 0 to 8 a, with ESCI reaching 8.82 and 28.50, respectively. The gains of soil fertility in the age stage from 8 to 14 a were the fastest. Conservation water did not suffer much loss at the beginning of afforestation. The windbreak and sand fixation gained significantly in the initial stage of afforestation, and gradually provided more stable windbreak and sand fixation function after 23 years of afforestation. Compared with Artemisia ordosica community, the biodiversity and carbon sequestration was in a positive state after 8 years of afforestation, the soil fertility was in a positive state after 14 years of afforestation, and all the functions were in a positive state after 34 years of afforestation. It was suggested that Salix psammophila could continue to utilize in plantation construction in Mu Us Sandy Land.