三峡库区消落带观赏草植物适生研究及对土壤氮磷的富集特征分析

Evaluation of Adaptability and Nitrogen,Phosphorus Absorption from Soil of Ornamental Grasses in Water-Fluctuation-Zone of the Three Gorges Reservoir

根据三峡库区消落带的环境特征,3年间通过在库区消落带实验基地的种植及实地淹没实验,对10种备选用于生态修复和景观提升的观赏草植物进行了适生性研究,并根据生态修复的需要,研究观赏草植物对氮磷养分的富集特征及其种间差异,为消落带高效截污植被的筛选提供基础数据.结果表明:①对于消落带的生态恢复和景观提升,可优先选择的观赏草植物有狗牙根、长芒稗,耐水淹,覆盖度高,145~175 m水位线之间生长良好;花叶芦竹、水烛香蒲、五节芒、结缕草,有一定耐淹性,可用于165~175 m水位线的造景区域;细叶芒、金叶菖蒲、芦苇、狼尾草,耐淹性差,仅可在175 m水位线周围生长.②不同观赏草植物的氮磷吸收富集能力差异有统计学意义.根据观赏草对氮磷的富集系数、累积吸收量和其地上生物量,可将消落带观赏草分为5类:氮磷富集系数较高型植物(花叶芦竹、五节芒);氮富集型植物(芦苇、水烛香蒲);磷富集型植物(细叶芒、狼尾草、结缕草);中氮磷富集型植物(狗牙根、长芒稗);弱氮磷富集型植物(金叶菖蒲).

Experiments were conducted for the purpose of choosing adaptable ornamental grasses to restore and reconstruct the ecosystem in Water-Fluctuation-Zone(WFZ)of the Three Gorges Reservoir(TGR)in Wanzhou,Chongqing.According to the needs of ecological restoration,research on ornamental grasses species'absorption capacity and their interspecific differences of soil nitrogen(N)and phosphorus(P)would provide important preliminary data for screening and rebuilding vegetation with high efficiency of pollutant interception in the TGR.Results show that,①Cynodon dactylon and Echinochloa caudata could complete their growth at 145-175 m water level;Arundo donax var.versicolor Stokes,Typhaangustifolia L.,Miscanthus floridulus and Zoysia japonica Steud could complete their growth at 165-175 m water level;Miscanthus sinensis,Acorus gramineus‘Ogon’,Phragmites communis and Pennisetum alopecuroides could complete their growth above 175 m water level,were considered as the candidate species for ecosystem restoration in WFZ.②There were significant differences of nutrients absorption ability among those ornamental grass species in WFZ.Ten ornamental grasses were classified into five types by plants'enrichment coefficient,cumulative uptake quantities and above-ground biomass.Arundo donax var.versicolor Stokes and Miscanthus floridulus were classified into a strong nitrogen and phosphorus enrichment group;Phragmites communis and Typhaangustifolia L.were in strong nitrogen enrichment group;Miscanthus sinensis and Arundo donax var.versicolor Stokes belonged to high phosphorus enrichment type;Cynodon dactylon and Echinochloa caudata were medium strength enrichment type;Acorus gramineus‘Ogon’was attached to low nitrogen and phosphorus enrichment group.