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通过现场调查取样和室内理化分析,研究了西藏东部主要河谷地区不同土地利用方式下土壤肥力性质及其随土地利用方式变化的机制。结果表明:不同土地利用方式下土壤理化性质有明显的差异,耕地和裸地土壤砂粒含量高于其他利用方式,本区域土壤砂质特征明显;受有机质积累影响,乔木林地、灌丛地土壤具有相对较高N素养分;受施肥等因素影响,农耕地土壤具有相对较高P、K养分;在所有利用方式中,裸地土壤尽管具有相对较高的粉粒含量,但所有养分指标均最低,显著低于林地土壤。总之,对于西藏脆弱生境而言,耕作使得有机质更易于消耗。由于有机质与植被之间存在明显互相促进的作用,因此维持土壤有机质平衡对于恢复植被、保护青藏高原东缘生态屏障具有重要的意义。
Through on-site sampling and indoor physical and chemical analysis, the paper studied the characteristics of soil fertility under different land use patterns in the major river valleys in eastern Tibet and their changes with land use patterns. The results showed that there were obvious differences in soil physicochemical properties under different land use patterns. Soil contents in arable land and bare land were higher than those in other ways. The characteristics of soil sandy soil were obvious. Under the influence of organic matter accumulation, Relatively high N nutrients; affected by fertilization and other factors, the cultivated soils had a relatively high P and K nutrient content; in all utilization modes, bare soil had the lowest content of all nutrients despite its relatively high silt content , Significantly lower than the woodland soil. In conclusion, for Tibet’s fragile habitat, cultivation makes organic matter more consumable. Due to the obvious mutual promotion of organic matter and vegetation, maintaining the balance of soil organic matter is of great significance for the restoration of vegetation and protection of the ecological barrier on the eastern edge of the Tibetan Plateau.