滇池流域富磷区退化山地马桑-蔗茅植物群落的生态修复效能评价

Assessment of ecological restoration function of the Coriaria nepalensis-Erianthus rufipilus community in the phosphorus-enriched degraded mountain area in the Lake Dianchi Watershed, Southwestern China

滇池流域富磷区退化山地面源污染的防控是滇池富营养化综合治理的重点区域和关键环节。为了了解富磷区退化山地典型植物群落的生态修复效能,该文以马桑(Coriaria nepalensis)-蔗茅(Erianthus rufipilus)群落为例,从群落构建过程、优势种的面源防控能力、形成群落的面源污染防控效能三个方面对该群落的生态修复效能进行研究。结果表明,马桑、蔗茅及其形成的马桑-蔗茅群落均可有效地降低地表径流量,悬浮颗粒,及土壤氮、磷流失,但马桑、蔗茅种群数量水平低,种群之间不存在显著的空间关联性。基于以上研究结果,建议在后期的生态修复过程中,通过增加马桑、蔗茅的数量,使二者之间达到空间正关联性,群落结构的完善不仅可以有效地抑制紫茎泽兰(Eupatorium adenophorum)的入侵,还可以进一步提高对退化山地面源污染的防控效能。

Aims Understanding the ecological restoration functions of the Coriaria nepalensis-Erianthus rufipilus commu- nity in phosphorus-enriched degraded mountain areas can guide ecological restoration and community assembly in degraded mountain areas. Our aim was to assess the degree of ecological restoration of the Coriaria nepalensis- Erianthus rufipilus community in three aspects： community assembly process and non-point source pollution con- trol of dominant species and the community. Methods We conducted a point pattern analysis of three dominant species （Coriaria nepalensis, Erianthus rufipilus and Eupatorium adenophorum） in a plot located on a degraded mountain of the phosphorus-enriched area in the Lake Dianchi Watershed in Kunming, Yunnan Province, China. The effects of dominant species and the reconstructive community on surface runoff and soil nutrient loss were monitored using runoff plots in the wet season. We compared surface runoff and nitrogen and phosphorus loss in these plots under natural rainfall condi- tions with reference plots. 1mportantfindings Coriaria nepalensis, Erianthus rufipilus and the reconstructive community of these two spe- cies effectively decreased surface runoff, soil loss and nutrients loss. The individual number of dominant species was low, and no significant associations were found in species pairs, which suggest each species＇ distribution patterns may be associated with specific habitats. These results indicate that the reconstructive community of C. nepalensis and Erianthus rufipilus could lead to effective ecological restoration in the phosphorus-enriched degraded mountain area of the Lake Dianchi watershed, but individual numbers of dominant species should be increased in this recon-structive community in order to develop community structure and control non-point source pollution loss.