摘要
沉生植物对维护和提高湖泊生态系统的生物多样性和稳定性，控制湖泊富营养化具有重要生态价值。对于可在水面形成致密冠层的沉水植物，生物量过大时可能会对水体功能产生不利的影响。实验通过对菹草（Potamogeton crispus）＋金鱼藻（Ceratophyllum demersum）群落中菹草在春季暴发时采取不同菹草收割强度（100%、80%、60%、40%、20%和0%的收割）进行生物量控制。每种收割处理均在底泥厚度为15 cm，水深为110 cm独立实验池中（4 m长x2 m宽x2.5 m深）进行。实验研究生物量调控对冬季种菹草与春季种金鱼藻交替及水质的影响，探讨群落中菹草的最佳生物量控制强度，为草型湖泊进行沉水植物生态管理提供依据。结果表明：在40%、20%和0%（未收割）菹草收割强度处理下菹草容易产生断枝并且整株上浮，更高强度的收割减小了植株受到的浮力，促进了群落中菹草和金鱼藻的生长，并延长了菹草的生命周期，推迟了菹草的上浮时间。菹草遮光效应在一定程度上促进了金鱼藻的生长，中等偏高强度的菹草收割使得菹草和金鱼藻均处在较高的生物量水平，维持了群落的稳定性。在菹草生长期对其进行60%-80%收割可维持水体营养盐在较低的水平，并能实现冬季种沉水植物菹草与春季种沉水植物金鱼藻在群落中有效交替，可缓解存留菹草衰亡给水质带来的不利影响，强化沉水植物群落的水质净化功能。
Submerged macrophytes are extremely important because they serve multiple ecological functions. The submerged macrophytes, called canopy formers, are notorious for forming dense mats of “topped-out” vegetation that can displace native plants, impede navigation, and reduce the aesthetic enjoyment of affected aquatic systems because the biomass disproportionately concentrates near the water surface. An experiment of biomass regulation was conducted in the rapid growth stage of submerged macrophytes under different harvest intensities （100%, 80%, 60%, 40%, 20% and 0% harvesting Potamogeton crispus ） inP. crispus-Ceratophyllum demersum community. Each harvest intensity was manipulated in a separate concrete water pond （4 m long, 2 m wide and 2.5 m deep） independently, with sediment thickness of 15 cm, and water depth of 110 cm. The effects of biomass regulation on the alternation of winter-spring species, and the water quality by harvest was studied. The objectives of this study were to discuss the best harvest intensity in the community, and provide a scientific basis for ecosystem management of submerged plants in the submerged plants dominated lakes. The results showed thatP. crispus were floated on the water under harvest intensity of 40%, 20% and 0% （no harvesting）, and higher harvest intensity decreased the buoyancy ofP. crispus, extended the life cycle ofP. crispus and postponed the floating date. The proper shading on water bodies byP. crispus promoted the growth of C. demersum, and high harvest intensity promoted the growth of bothP. crispus andC. demersum to maintain the stability of the community. The nutrient of water can be maintained at a low level under harvest intensity of 60% to 80% in the growth phase of P. crispus which can achieve efficacious alternation of winter-species P. crispus and spring-species C. demersum in the community. Harvesting alleviated adverse effects of theP. crispus decline to water quality, and consolidated the water purification function of submerged plant comm
出处
《生态环境学报》
CSCD
北大核心
2015年第7期1222-1227,共6页
Ecology and Environmental Sciences
基金
国家自然科学基金项目(NSFC41230853)
国家水体污染控制与治理科技重大专项项目(2014ZX07101-011)
中国科学院重点部署项目(KZZD-EW-10)
关键词
生物量调控
收割强度
群落
金鱼藻
盖度
biomass regulation
harvest intensity
communities
Ceratophyllum demersum
coverage
