Growth of water hyacinth biomass and its impact on the floristic composition of aquatic plants in a wetland ecosystem of the Brahmaputra floodplain of Assam, India

• DOI: 10.7717/peerj.14811
• Publication Date: 2023-02-03T09:28:00Z
• Authors: Durlov Lahon; Dhrubajyoti Sahariah; Jatan Debnath; Nityaranjan Nath; Gowhar Meraj; Majid Farooq; Shruti Kanga; Suraj Kumar Singh; Kesar Chand
• Keywords: Spatial information sciences; Biomass (ecology); QH301-705.5; Hybrid Wetlands; 01 natural sciences; Industrial and Manufacturing Engineering; Environmental science; Agricultural and Biological Sciences; Importance of Mangrove Ecosystems in Coastal Protection; Floodplain; Biological Control of Invasive Species Management; Water hyacinth; Humans; Application of Constructed Wetlands for Wastewater Treatment; Biomass; Biology (General); Agroforestry; Water Hyacinth; Biology; Ecosystem; 0105 earth and related environmental sciences; Ecology; Geography; Statistics; R; Life Sciences; Paleontology; Biodiversity; 15. Life on land; Plants; Pollution; 6. Clean water; Floristics; Macrophyte; Aquatic plant; Eichhornia; 13. Climate action; Wetlands; Insect Science; FOS: Biological sciences; Environmental Science; Physical Sciences; Wetland; Hyacinth; Medicine; Species richness

Inland water plants, particularly those that thrive in shallow environments, are vital to the health of aquatic ecosystems. Water hyacinth is a typical example of inland species, an invasive aquatic plant that can drastically alter the natural plant community’s floral diversity. The present study aims to assess the impact of water hyacinth biomass on the floristic characteristics of aquatic plants in the Merbil wetland of the Brahmaputra floodplain, NE, India. Using a systematic sampling technique, data were collected from the field at regular intervals for one year (2021) to estimate monthly water hyacinth biomass. The total estimate of the wetland’s biomass was made using the Kriging interpolation technique. The Shannon-Wiener diversity index (H′), Simpson’s diversity index (D), dominance and evenness or equitability index (E), density, and frequency were used to estimate the floristic characteristics of aquatic plants in the wetland. The result shows that the highest biomass was recorded in September (408.1 tons/ha), while the lowest was recorded in March (38 tons/ha). The floristic composition of aquatic plants was significantly influenced by water hyacinth biomass. A total of forty-one plant species from 23 different families were found in this tiny freshwater marsh during the floristic survey. Out of the total, 25 species were emergent, 11 were floating leaves, and the remaining five were free-floating habitats. Eichhornia crassipes was the wetland’s most dominant plant. A negative correlation was observed between water hyacinth biomass and the Shannon (H) index, Simpson diversity index, and evenness. We observed that water hyacinths had changed the plant community structure of freshwater habitats in the study area. Water hyacinth’s rapid expansion blocked out sunlight, reducing the ecosystem’s productivity and ultimately leading to species loss. The study will help devise plans for the sustainable management of natural resources and provide helpful guidance for maintaining the short- to the medium-term ecological balance in similar wetlands.