CHAPTER ONEINTRODUCTION1.1 Background of the StudyWetlands are regarded as biodiversity isles because they support extensive food chains and rich biodiversity. In this sense, these ecosystems are important sites for conservation (Getzner, 2002). Almost 50% of the world’s wetlands have disappeared in the last century due to Agriculture and Urban Development (Shine and Klemm, 1999). In Europe, the situation is critical with the loss of almost 2/3 of wetlands by the beginning of the 20thcentury. (Santamarıa and Klaassen, 2002).Wetlands are important habitats for many species of plants and animals at both national and international levels (Hebb et al., 2013; Wetser et al., 2015). A contribution to our understanding of how a community is put together, how it works, what determines the relative proportions of community members, and their spatial and temporal relationships with each other might contain something of value for describing wetlands.Aquatic macrophytes, often also called hydrophytes, are key components of aquatic and wetland ecosystems. As primary producers, they are at the base of herbivorous and detritivorous food chains, providing food to invertebrates, fish and birds, and organic carbon for bacteria. Their stems, roots, and leaves serve as a substrate for periphyton, and a shelter for numerous invertebrates and different stages of fish, amphibians, and reptiles (Dvořák,1996). Biogeochemical processes in the water column and sediments are to a large extent influenced by the presence/absence and a type of macrophytes, and macrophytes can also have a profound impact on water movement and sediment dynamics in water bodies. Some macrophytes are of major importance for their direct contributions to human societies by providing food, biomass, and building materials (Engelhardt and Ritchie, 2001; Egertson et al., 2004; Bornette and Puijalon 2011). Good knowledge of the functions of aquatic macrophytes in wetlands and shallow lake ecosystems is critical for understanding the basic ecosystem processes. It is also important for numerous applied issues such as anthropogenic perturbations, wetland restoration, wastewater treatment, and management of invasive species (Lavoie, 2010; Casanova, 2011).Soils in wetlands are characterized by a high degree of spatial variability due to a combination of physical, chemical, and biological processes that operate with different intensities at different scales. These processes in wetland ecosystems include for example; surface run-off, erosion, overbank flooding, sediment deposition, groundwater inputs, fire, animal burrowing, litter production, and root activity (Bruland and Richardson, 2005). The distribution of plant species in wetlands varies along with different environmental conditions. For instance, flood-sensitive plants are usually distributed at higher-elevation sites because of their low tolerance to flooding, whereas flood-tolerant species usually occur at lower elevations (Luo et al., 2008). While some studies have shown that pedological attributes such as textural class, pH, and nutrients among others, play significant roles in regulating vegetation patterns (Ubom, et al., 2012; Kwon et al., 2007), others have shown that in studying macrophyte-environment used various techniques are used to assess aquatic macrophytes and most have reported measurements of diversity, richness, frequency, and community composition (Akasaka and Takamura, 2011).In view of the significant role played by macrophytes in freshwater ecosystems, understanding and quantifying the environmental factors that influence the distribution patterns of macrophytes is indispensable for integrated management practices of these ecosystems.