黔西北不同演替阶段植物群落养分质量诊断与经营策略

Nutritional Quality Diagnosis and Management Strategy of Plant Community at Different Succession Stages in Northwest Guizhou

以黔西北5个演替阶段的植物群落为研究对象,测定12项有关土壤和凋落物养分的指标,分析养分含量变化规律,同时运用主成分分析评价法对各植物群落进行养分质量评价。结果表明:1)黔西北地区各演替阶段植物群落土壤有机质、全氮和碱解氮含量均为灌木阶段>乔林阶段>灌丛阶段>乔灌阶段>乔幼林阶段,随着演替的正向进行,其他土壤养分指标无明显变化规律,凋落物养分总体呈升高趋势;2)养分质量综合指数为灌木阶段(1.510)>乔林阶段(0.938)>灌丛阶段(-0.737)>乔幼林阶段(-0.771)>乔灌阶段(-0.940)。结合植物群落养分差异分析和养分质量评价结果,可采取凋落物原位保护、植物群落结构调整等经营措施提高森林生态系统养分质量。

The sustainable degradation of plant communities accelerates the process of rocky desertification in the karst area of northwest Guizhou. So it is of great significance to evaluate the plant communities' nutrient quality for its sustainable management at this region. In this paper,The plant communities in five successional stages were used to study the 12 kinds of nutrient indicators of soil and litter to analyze the nutrient changing laws further. Besides,the integrated fertility index of each plant community was evaluated by principal component analysis to provide scientific basis for forest restoration and protection of karst degraded ecosystem. The results showed that: 1) The contents of soil organic matter,total nitrogen and available nitrogen in plant communities were followed by Rhododendron simsii-Populus alba( RP) > Betula luminifera( B) > Quercus variabilis + Corylus heterophylla( QC) > Pinus yunnanensis + Populus alba-Betula luminifera( PPB) > Populus alba + Betula luminifera( PB). With the evolving of succession in the positive direction,the other soil indexes did not show any specific characteristics,and the nutrient of litter was increasing; 2) The comprehensive index of nutrient quality was RP( 1. 510) > B( 0. 938) > QC(-0.737) > PB(-0. 771) > PPB(-0. 940). Based on the analysis of nutrient diversity and nutrient quality of plant community,the management measures such as litter protection and plant community structure improvement could be used to improve the nutrient quality of forest ecosystem.