Wetland diversity – A reference to lacustrine macrophyte species

1.1 Wetlands in general

On the Earth's surface, water and life are inextricably connected. The earliest life originated from water and the first organism on the earth was aquatic. Water has numerous distinct characteristics that make it suited for life (Vijayan et al., 2018). Wetlands are regions of our landscape that are defined by the presence of water, where water dictates or influences the majority, if not all, of a field's biogeochemistry, or the biological, chemical, and physical characteristics of a specific site (Gardner et al., 2015). Wetlands serve as the interface and ecotone habitat between the terrestrial ecosystem and the aquatic ecosystem. It indicates that wetlands are neither entirely aquatic nor terrestrial; depending on seasonal fluctuation, they may be both at a similar moment, which contains the water and aquatic life, two essential components of the ecosystem (Walton et al., 2020). Wetlands are geologically young and ecologically delicate; they exist in all climates and vary sporadically with the passage of time and season. Wetlands are found across the world except in the Antarctica region. The Earth has 5.3 to 12.8 million km² of wetland area (Gardner et al., 2018). Wetlands are natural water bodies, that support a huge number of floral and faunal diversity. Due to the diverse geographical location, dominant species, their genesis, water chemistry, and sediment or soil characteristics; wetlands express rich biodiversity (Barbier, 2011). Globally, wetlands are a highly adaptive, productive, and biologically rich ecosystem, provides many significant private and public services to society with both consumptive and non-consumptive benefits. Wetlands are known as “Biological Supermarket”, “Cradles of Biodiversity”, “Kidney of Nature” and “Repository of Resources” because wetlands are multifaceted in terms of ecological nature,  hydrological processes, environmental relevance, management boundaries, as well as economic and therapeutic value (Garg, 2015; Sarkar & Das, 2016; Mengesha, 2017; Burdick, 2018; Ghosh et al., 2018). Wetland ecosystems are a natural wonder and a source of future prosperity; agriculturists, botanists, ecologists, and others have been interested in the study of wetlands for many years, but it wasn't until the 1970s that they realized the importance of wetlands. Since then, the image of wetlands has transformed from a mosquito-infested wasteland to a vital natural region. Natural and social scientists, landscape scientists, landscape architectures, environmental managers, urban designers, and many others are now paying close attention to wetlands.