基于挂网喷播绿化的岩质边坡植物多样性及影响因素分析

【目的】通过对江苏省3种岩质边坡植物群落的调查,研究基于挂网喷播绿化技术的岩质边坡植物多样性及影响因素,为岩质边坡生态治理和植被恢复提供科学依据。【方法】利用多元统计分析方法计算岩质边坡土壤养分指数,采用灰色关联度表征边坡植物多样性与土壤因子的耦合程度,借助RDA法分析边坡植物多样性与环境因子的关系。【结果】①在3种岩质边坡植物群落中,蔷薇科、豆科、木犀科、菊科和禾本科植物共占总物种数的54.4%,表明这5科植物在岩质边坡生态修复过程中所起作用最大; ②不同坡位的植物多样性指数差异较大,Margalef指数、Shannon-Wiener指数、Pielou指数、Simpson指数均呈现上坡<中坡<下坡; Margalef指数在坡向上呈现阳坡<阴坡; ③土壤有机质、全氮、速效磷、速效钾是对岩质边坡植被恢复起关键作用的因子; ④3种岩质边坡植物多样性与土壤因子的耦合协调程度以弱协调为主,各种岩质协调关系大小依次为花岗岩边坡<灰岩边坡<砂岩边坡,与边坡土壤肥力变化一致。【结论】通过挂网喷播绿化的岩质边坡自然恢复6 a后,边坡植物多样性逐渐上升但尚未达到稳定状态。绿化施工时应充分考虑乡土植物如蔷薇科、禾本科等作为喷播植物种,适量施肥并加强上坡的人工管护。
Abstract: 【Objective】 By means of plant community investigation based on greening technique of net-suspended spray seeding,the plant diversity and its influencing factors on three types of rocky slope were studied to provide scientific references for ecological management and vegetation restoration on rocky slopes in Jiangsu Province.【Method】 The soil nutrient index was calculated using a multivariate statistical analysis method. The gray relational degree was used to characterize the degree of coupling between slope plant diversity and soil factors. The relationships between slope plant diversity and environmental factors were analyzed by RDA.【Result】①In the plant communities of the three rocky slope types, plants from Rosaceae, Leguminosae, Oleaceae, Compositae and Gramineae accounted for 54.4% of the total species, indicating that these five families played the most important role in the eco-restoration. ②Plant diversity indices were significantly different among the different slope positions. The Margalef, Shannon-Wiener, Pielou and Simpson indices all showed a consistent trend, i.e., upper slope < middle slope < lower slope. The Margalef index indicated a sunny slope < shady slope tendency for the slope aspect. ③The organic matter, total nitrogen, available phosphorus, and available potassium were the key indices in the process of eco-restoration. ④The degree of systematic coupling coordination between plant diversity and soil factors was given priority at a weak level, i.e., granite slope < limestone slope < sandstone slope. It was consistent with soil fertility of the slopes.【Conclusion】 After 6 years of natural restoration on the rocky slopes based on net-suspended spray seeding, the plant diversity of slopes increased gradually and had not reached the steady state. Full consideration should be given to local plants when greening project, especially the Rosaceae and Poaceae families, and fertilizer enhances the artificial management of the upper slope