【作者】 陈祖拥；

【导师】 刘方；

【作者基本信息】 贵州大学 ， 土壤学， 2009， 硕士

【摘要】 为给喀斯特脆弱生态系统的植被恢复提供理论依据,对贵州南部喀斯特森林退化过程中土壤理化性质、土壤酶活性及土壤呼吸强度进行了分析,主要得出以下结论:喀斯特原始森林生态系统不同小生境类型土壤理化性质、酶活性及土壤呼吸强度变化差异较大。各小生境土壤以壤土为主,土壤团聚体数量较多,石洞和石缝土壤粘粒含量平均相对较高,而石坑土壤砂粒含量较高。在石缝和石坑土壤中的有机质含量较高,分别是石洞土壤的5.54倍和4.87倍。原生林中不同小生境土壤,有机质、全氮、碱解氮、有效磷、速效钾含量变化均有相同的变化趋势,即石缝>石坑>石沟>土面>石洞。除土壤脲酶和蛋白酶之外,石缝土壤呼吸强度、过氧化氢酶活性、碱性磷酸酶活性和蔗糖酶活性都相对其他四类小生境土壤要高。而整体上来讲石沟、石缝和石坑这三种负地形小生境土壤的各种酶活性和土壤呼吸强度要比石洞和土面土壤要高。在喀斯特森林由原生林→次生林→灌木林→灌丛草地演替的过程中,每个样地的土面、石沟及石洞三者的面积之和都超过了95%;石沟、石洞和土面土壤砂粒含量没有明显的差异,而粉粒和粘粒含量略有增加,土壤由壤土或粉砂质壤土发展为粘壤土或壤质粘土。石沟、土面土壤有机质、全氮、速效氮、磷、钾含量明显下降,其中灌丛草地和原生林地相比石沟土壤分别下降了28.88%、29.77%、23.80%、31.17%、61.74%和49.21%,土面土壤分别下降了45.12%、37.39%、15.86%、36.24%、69.44%和48.00%。石洞土壤养分含量没有明显的下降趋势。在喀斯特森林由原生林→灌丛草地演替过程中,石沟和土面土壤脲酶活性、土壤呼吸强度都逐步下降,灌丛草地和原生林地相比,石沟土壤呼吸强度、脲酶、蛋白酶和碱性磷酸酶活性分别下降了34.49%、52.83%、37.50%和27.80%,土面土壤则分别下降了24.09%、74.71%、63.13和43.20%;而石沟土壤过氧化氢酶和蔗糖酶活性分别增强了5.57%和78.36%,土面土壤则分别增强了19.90%和211.11%。灌丛草地和原生林地相比,石洞土壤呼吸强度、脲酶和蛋白酶活性分别下降了6.87%、35.89%和39.27%,而过氧化氢酶和蔗糖酶活性则分别增强了8.51%和63.40%。因子分析表明在喀斯特森林由原生林→灌丛草地演替的过程中,第一主因子主要由磷酸酶活性、土壤呼吸强度、有机质、全氮、全磷、缓效钾、碱解氮、速效磷和速效钟决定,第二主因子主要由脲酶活性和pH值决定,第三主因子主要由蛋白酶活性决定,第四主因子主要由粘粒含量决定。进行相应计算表明,原生林地、次生林地、灌木林地和灌丛草地石沟土壤土壤退化指数(DI)分别为0%、-14.32%、-25.59%和-37.72%,石洞土壤土壤退化指数分别为0%、2.16%、7.63%和-9.77%,土面土壤土壤退化指数分别为0%、-28.80%、-41.19%和-45.72%;而石沟土壤质量综合指数(QI)分别为83.48%、63.18%、42.35%和10.64%,石洞土壤质量综合指数分别为42.43%、60.83%、75.30%和27.22%,土面土壤质量综合指数分别为83.97%、38.64%、28.62%和24.70%。更多还原

【Abstract】 The soil physical and chemical properties, the soil enzyme activities and the soil respiration during the process of forest degradation were studied to provide the theoretical baswas for revegetation in Karst region with the frail ecosystem. And mainly draws following conclusion:There was great difference between each micro-habitats for the soil physical and chemical properties, the soil enzyme activities and the soil respiration in the karst virgin forest ecosystem. Most of the texture were loam soil in each micro-habitats, the quantity of the soil aggregate were many, the content of the soil clay particle in the Stone cave and Rocky crevice were high in mean relative, besides the soil sand particle in the Stone pit were high. The content of organic matter were high in the soil of the Rocky crevice and Stone pit, it was 5.54 and 4.87 times of the Stone cave respectively. In the original forest, there was a same trend between the content changes of organic matter, total nitrogen, available nitrogen, Available P and the Available K in each micro-habitats, it was that Rocky crevice > Stone pit > Rocky gully > Soil surface > Stone cave. Except for the soil urease and Proteinase the soil respiration, the soil Catalase activities, alkaline Phosphatase activities and the soil alkaline activities were higher in Rocky crevice than which in other four kind of micro-habitats. In a word the soil respiration and each of the soil enzyme activities in Rocky gully, Rocky crevice and Stone pit which were negative orography micro-habitats were higher than which in Stone cave and Soil surface.During the process degradation of Karst forest from original forest to secondary forest to bush forest to bush-grass land, the werea sum for the three of the Rocky gully, Stone cave and Soil surface was more than 95% in every type place. There were no obvious difference of the soil sand particle content between the Rocky gully, Stone cave and the Soil surface, but there was a little increased of the soil silt particle and the soil clay particle. There was a trend of the albic soils from silty loam or loam to clay loam or loamy clay. The content of the organic matter, total nitrogen, alkalyswas N, available P, active K were obviously decreased during the process degradation. Among of them the content of the soil Rocky gully in bush-grass land decreased respectively by 28.88%, 29.77%, 23.80%, 31.17%, 61.74% and 49.21%,and the soil surfaced decreased respectively by 37.39%, 15.86%, 36.24%, 69.44% and 48.00%, Compared to which in original forest .There was no obviously decreased of the soil nutrient content in Stone cave.During the process degradation of Karst forest from original forest to bush-grass land, the soil urease activities and the soil respiration were gradually decreasing in the soils Rocky gully and Soil surface. Compared to which in original forest, the soil respiration, the soil urease activities, the Proteinase activities and the alkaline Phosphatase activities of the soil Rocky gully in bush-grass land decreased respectively by 34.49%,52.83%,37.50% and 27.80%, while the soil respiration and the three soil enzyme activity of the soil surface in bush-grass land decreased respectively by 24.09%,74.71%,63.13 and 43.20%. Contrast with the soil Catalase activities and the Invertase activities of the Rocky gully in bush-grass land increased respectively by 5.57% and 78.36%, Compared to 19.90% and 211.11% of the Soil surface. Compared to which in original forest, the soil respiration, the soil urease activities and the Proteinase activities of the soil Stone cave in bush-grass land decreased respectively by 6.87%,35.89% and 39.27%,oppositely the soil Catalase activities and the Invertase activities increased respectively by 8.51% and 63.40%.The result of the principal factor analysis demonstrates that: during the process degradation of Karst forest from original forest to bush-grass land, the first principal factor determined by Phosphatase activities, the soil respiration, organic matter, total nitrogen, total phosphorus, slowly available K, available nitrogen, Available P , the Available K; the second principal factor determined by the soil urease activities and pH; the third principal factor determined by Proteinase activities; the forth principal factor determined by soil clay particle content. The result of the corresponding calculation analysis demonstrates that: The Soil Deterioration Index of soils rocky gully in original forest land, secondary forest land, bush forest land and the bush-grass land were 0%, -14.32%, -25.59% and 37.72% respectively. While the Soil Deterioration Index of Stone cave soils respectively were 0%, 2.16%, 7.63% and -9.77%, the Soil Deterioration Index of Soil surface respectively were 0%、-28.80%、-41.19% and -45.72%. Compared with this, the Soil Quantity Index of rocky gully soils in original forest land, secondary forest land, bush forest land, bush-grass land were 83.48%, 63.18%, 42.35% and 10.64% respectively. The Soil Quantity Index of Stone cave soils were 42.43%, 60.83%, 75.30% and 27.22% respectively. The Soil Quantity Index of Soil surface were 83.97%, 38.64%, 28.62% and 24.70% respectively.更多还原