不同基材边坡土壤肥力变化趋势预测——以向家坝水电站工程区为例

目的]对向家坝水电站工程区7种不同基材边坡土壤在2005—2014年的肥力进行测定和分析,并预测未来肥力变化趋势,旨在为大型水利水电工程区边坡植被重建及生态恢复提供理论与技术支撑。方法]运用灰色理论研究各肥力因子间的灰色关联度,以此确立主要肥力因子来表征土壤肥力,而后建立Logistic预测模型探讨土壤肥力未来25a的变化情况。结果]微生物量与其他肥力因子间的灰色关联度均大于其他肥力因子相互之间的灰色关联度,可作为主要肥力因子来表征土壤的肥力水平;2005—2040年上述边坡土壤微生物量(肥力水平)总体表现为:天然林天然次生林植被混凝土边坡厚层基材框格梁回填土客土喷播弃渣地。结论]随着时间的推移,各边坡土壤的微生物量(肥力水平)将最终趋向稳定,在人工营造的边坡植被生境中,植被混凝土边坡的土壤肥力表现最佳。

Trend Prediction of Soil Fertility of Various Substrate Slopes -A Case Study of Xiangjiaba Hydropower Project Area

Objective] Soil fertilities of seven substrate slopes in Xiangjiaba hydropower project area were measured in the years from 2005 to 2014. The changing trend of soil fertility was predicted to provide theoretical and technical support for slope vegetation restoration in large water conservancy and hydropower project. Methods] Grey theory and logistic equation were integrated to establish a structurally sound and high-precision logistic model for forecasting the future trend of main soil fertility. The main soil fertility was decided by Grey correlation degree among various soil fertility factors in different slopes. Results] Grey correlation degrees between microbial biomass and other fertility factors were all larger than the ones among other fertility factors, and thereby the soil microbial biomass can be regarded as the main soil fertility factor and denote the soil fertility level. Soil fertilities indicated by microbial biomass were predicted having an overall order in 2005-2040 that is natural forest(NF) >natural secondary forest(NSF) >vegetation-growing concrete gunning(VGCG) >thick layer substrate(TLS) >framed beams and soil covered(FBSC) >external-soil spray seeding(ESS) >discarded residue(DR). Conclusion] Soil microbial biomass on different substrate slopes will eventually get stable with the time pass by. The VGCG slope''s fertility level is the best.