中文摘要：

海草是分布于全球各地浅海中的重要沉水被子植物,具有极高的应用价值;海草与周围环境形成一个独特的生态系统——海草场生态系统,是生物圈中最具生产力的水生生态系统之一,且强大的吸收和固碳能力使其成为全球最大的碳库之一;海草场具有多种重要的生态服务功能;被广泛视为是理想的＂生态哨兵＂来衡量近海岸生态系统健康状况。如今由于自然因素和人为破坏活动的双重干扰,全球海草种的数量和海草场的覆盖面积正在急剧减少,海草生存状况面临严峻的考验,约14%的海草种处于灭绝的边缘,1/3的海草场彻底消失。目前,海草监测工程和以生境恢复与人工移植为主的海草保护恢复工程已经开始实施,并取得初步成效,对今后全球范围内海草保护恢复工作具有重要指导作用,但该工程还仅仅处于起步阶段,取得更多技术理论上的突破和政策上的支持才能实现挽救濒危海草种及缓解海草场生态系统破坏现状的目标。本文通过对全球海草及海草场生态系统研究成果的总结,阐述了海草和海草场对全球生物圈的重要性以及面临的严峻生存压力,以期提高公众对海草的认识,并唤起人们保护海草的意识。

英文摘要：

Seagrasses are underwater flowering plants widely distributed in shallow seas often forming vast seagrass based ecosystems.Seagrass ecosystems are one of the most productive aquatic ecosystems in the world and a globally significant carbon store due to the unique features of seagrass which allow efficient photosynthesis underwater.Seagrass ecosystems provide a range of important ecological service functions and they act as biological sentinels used to assess the health of coastal ecosystems.Recently,rapidly decreases in the number of individual seagrass species and the number of seagrass meadows caused by the multiple stressors including natural factors and human effects had led to a situation where 14% of all seagrass species are at risk of extinction and about one-third seagrass meadows have disappeared worldwide.In response to this decline,there has been a significant increase in the number of marine protected areas during the last decade,including seagrass monitoring and restoration projects which aim to prevent the extinction of individual seagrass species and prevent the large scale loss of seagrass meadows throughout the world.Current restoration projects involve habitat improvement through reduction in eutrophication or alteration of hydrology and the use of artificial transplantations which can be an effective method of restoration.Seagrass monitoring and restoration projects have achieved some positive preliminary results and provide useful guidelines for seagrass restoration.However there are challenges including limited theoretical approaches,appropriate technology,and uncertainty of outcome from seagrass transplantation and restoration projects and cost.This paper reviews the research on seagrasses and seagrass ecosystems globally,clarifies their importance to the biosphere and the risks to their survival to raise the awareness of the public,government and international agencies of the need to protect seagrass ecosystems.