Abstract
Wetlands show a diversity of appearances like salt marshes, tidal wetlands, inland freshwater wetlands, riparian wetlands, peat lands, and many other types. Each of the types host diverse biotic communities of flora and fauna. This biodiversity changes according to the physical and chemical properties of wetlands, climate, and the geological location. This biodiversity regulates the local ecosystem, carbon sequestration, fuelwood supply, fishery-based industries, and on many other ecological and socioeconomic aspects. In addition, the wetlands have other ecological aspects like maintaining freshwater quality by sedimentation, nutrient conservation, etc. However, around the world, the wetlands are subjected to several types of threats like both anthropogenic and natural. This study is a short review work on some of the outcomes of the studies of researchers around the world to see the importance of different types of wetlands, the threats to them by anthropogenic or natural causes, and focus areas for management strategy development.
TopIntroduction
Each of the wetlands can be an individual ecosystem. They are different by species composition, geologic location, their exposure to the different types of landscapes, climate and many other factors. Their surroundings, water sources, atmosphere etc. can regulate them as wetlands can regulate them also. Brinson (1993) pointed out that though wetness of wetlands are usually studied for understanding their function, but these functions can be potentially effected by drainage network, size of wetland, source of water, biogeochemical inflow and outflow etc. Hence to understand the function of wetlands, each wetland can be studied while considering these and many other factors, according to the uniqueness of the wetland. The biodiversity, climate, water and hydrological regime, ecosystem services, soil and sediments, anthropogenic dependence and activity, pollution status etc. in and around the wetlands are interdependent. So, trying to identify a particular cause of degradation of wetland ecosystem and applying a restoration strategy may or may not result into complete success depending on the other regulating factors as well as factors that were remained unstudied. The understanding of total biotic and abiotic setup is necessary for the conservation strategy development. This particular study is a review of the outcomes of the efforts of researchers to understand the ecological and economic importance of the wetlands and the major causes of their vulnerability. Separate headings and subheading are used to focus on individual factors, however interconnection of these factors are well established by the researchers and in this literature review some of those connections are mentioned. The examples mentioned here to establish the importance and role of different factors in regulation of the wetland ecosystem are only some of the vast research works that have already been done, and yet some factors may remain unmentioned here which may be of equivalent importance to develop conservation strategy for conservation and restoration of the wetlands.