黔中白云岩石漠区小流域土地利用变化及生态效益

为明析灰质白云岩石漠区和砾质白云岩石漠区综合治理工程中植被恢复模式的治理效果,采用科研示范和工程治理相融合、遥感影像和实地调查相结合的方法,在黔中不同白云岩组石漠化小流域分析了相应研究区及不同林草恢复模式的生态效益变化。结果表明:(1)普定研究区属灰质白云岩石漠区,凯里研究区属砾质白云岩石漠区,2016年2个研究区农林地景观基质相似度较高,普定研究区石漠化趋势性较强。(2)2016—2020年,普定研究区和凯里研究区林地面积转入量>转出量、耕地面积转入量<转出量。植被覆盖率增加、土壤侵蚀模数降低和石漠化等级面积率降低,普定研究区综合治理生态效益显著。(3)普定研究区和凯里研究区植被覆盖率增加量、土壤侵蚀模数降低率和石漠化等级面积降低率呈生态修复模式>封山育林模式>草地畜牧业模式的变化趋势,生态修复模式和封山育林模式的生态效益呈普定研究区>凯里研究区的变化趋势。综上,具有相似景观背景的石漠化小流域经综合治理后,呈植被覆盖率增加、土壤侵蚀模数降低和石漠化等级面积率降低的趋势,石漠化治理效果呈生态修复模式>封山育林模式>草地畜牧业模式的变化趋势,灰质白云岩石漠区治理效果比砾质白云岩石漠区显著。

Changes in Land Use and Ecological Benefits in Different Small Watersheds with Dolomite Rock Desertification in Central Guizhou Province

To analyse the governance effect of the vegetation restoration mode of the comprehensive treatment project in various calcareous dolomite deserts and gravelly dolomite deserts, the changes in the ecological benefits of different forest and grass restoration modes in small watersheds with dolomite rocky desertification in central Guizhou Province were analysed using a method integrating scientific research, engineering management, remote-sensing imagery, and field investigations. The results showed that:(1)The Puding research area(PDRA)belongs to a calcareous dolomite rocky desertification area, and the Kaili research area(KLRA)belongs to a gravelly dolomite rocky desertification area. The landscape matrix similarity of the agriculture and forests in PDRA and KLRA is high, and the rocky desertification trend in PDRA was strong in 2016.(2)From 2016 to 2020, in both PDRA and KLRA, the input amount was higher than that of the output in forestland, while the relative value was to the contrary in farmland. Additionally, the vegetation coverage rate increased and the soil erosion modulus and the rate of development of the rocky desertification grade areas decreased. The ecological benefit of the comprehensive control in PDRA was remarkable.(3)It was observed that as the vegetation coverage increases, the soil erosion modulus decreases, and the rocky desertification grade area decreases most in the ecological restoration model and least in the grassland animal husbandry model. The ecological benefits of the ecological restoration model and the closed forest model in PDRA are higher than those in KLRA. In general, after comprehensive treatment in similar small watersheds with rocky desertification, it was observed that the vegetation coverage rate increased and the soil erosion modulus and the rate of development of the rocky desertification grade areas decreased. The governance effect of rocky desertification was observed most in the ecological restoration model and least in the grassland animal husbandry model, ergo, the governance effect of calcareous dolomite desert was better than that of gravelly dolomite desert.