盐沼植物群落研究进展：分布、演替及影响因子

盐沼是全球温带及亚热带地区的主要滨海湿地类型之一,在我国分布广泛。盐沼湿地生态系统敏感、脆弱且具有重要的生态系统服务功能。理解盐沼植物群落时空分布动态的一般规律与生态学机制,是开展盐沼生态系统研究的基础与关键。海陆交界的特殊环境特征是影响盐沼湿地植物群落的空间分布及演替过程的主要因素。在海洋潮汐作用下,盐沼湿地中的盐度、水淹强度、氧化还原电位等非生物因子往往呈梯度分布,这也导致了生物群落中种内、种间关系的变化。在非生物及生物因子的共同作用下,盐沼植物群落也往往沿高程梯度呈带状分布。环境变化是盐沼植物群落演替的驱动因素,在海岸线相对较为稳定的盐沼,植物群落的演替多属自发演替,而在靠近的大型河口的一些持续淤涨的盐沼,植物群落演替通常属于异发演替。沿海地区的水产业、流域上游及沿海地区的工程、污染及生物入侵等直接或间接的人类活动已对盐沼湿地植物群落的产生了深刻影响。经过数十年发展,国际上盐沼植物群落学研究的热点领域主要包括盐沼植物群落与其他生物群落的相互关系、植物群落在盐沼生态系统过程中的作用等。在全球变化背景下,盐沼植物群落对气候变化与海平面升高也日益成为盐沼植物群落学相关的热点。

Review on salt marsh plant communities: distribution, succession and impact factors

Salt marsh,as a common coastal wetland,is widely distributed in temperate and subtropical regions of the world.Salt marsh plays an important role in the coastal food web and exporting of nutrients to the sea,which provides great valuable ecosystem services for human society.Understanding the general pattern and ecological mechanisms of temporal and spatial dynamics of salt marshes is the important basis in the salt marshes ecological studies.Salt marsh lies at the sea-land interface,and the special environmental characteristics lead to the special patterns of spatial distribution and succession process of salt marsh plant communities.Affected by the sea tides periodically,abiotic factors such as salinity,water depth and redox potentials vary along the elevation gradient.Thus,the intra-and interspecific relationships of biotic communities are altered gradually.Due to the interactions between abiotic and biotic factors along the elevation gradient,plant zonation is found very common in salt marshes in the world.Environmental change is the driving factor of the succession of salt marsh plant communities.Generally,the autogenic successions of plant communities occur on the relatively stable coastline,while allogenic successions occur in the silting and developing salt marshes near by the large estuaries.Salt marshes are fragile and sensitive to environmental changes.In the past decades,direct and indirect human activities,such as aquaculture,physical destruction of habitat,pollution and biological invasions have had great impacts on the salt marshes in the world.At present,salt marsh plant communities’ researches are focused on the relationships between salt marsh plant communities and other biotic communities,and the functions of plant community in salt marsh ecosystem process.In the context of global climate change,the responses of salt marsh plant communities to the global warming and sea-level rising become a hot spot as well.