ATLAS OF MANGROVE WETLANDS OF ANDHRA PRADESH
Title | ATLAS OF MANGROVE WETLANDS OF ANDHRA PRADESH |
Publication Type | Monograph |
Year of Publication | 2025 |
Authors | Ramasubramanian R, Nagarajan R, Niklesh S., Preethi G., Pandey SPriya |
Publisher | M S Swaminathan Research Foundation |
Keywords | Andhra pradesh, Atlas, India, Mangrove Wetlands |
Abstract | Mangrove wetlands are unique coastal ecosystems characterised by salt-tolerant trees and shrubs typically found in the tropical and subtropical coastlines, especially in estuarine areas where the water is saline. Mangrove ecosystems are one of the important natural resources that offer both ecological and economic benefits to coastal communities. Mangrove ecosystems occur on approximately 75% of the world’s tropical coastlines, between 25°N and 25°S. However, the extent of mangroves extends beyond these areas due to the movement of warm waters from the equator, as seen on the east coast of Africa, Australia, and New Zealand, where mangrove wetlands are found between 10° and 15° farther south. Similarly, in Japan, Florida, Bermuda, and the Red Sea, mangroves extend between 5° and 7° farther North. Mangrove plants possess structural adaptations, such as prop roots, pneumatophores, and knee roots, as well as buttressed stems, which allow them to survive in waterlogged, anoxic soils. These adaptations anchor them firmly in muddy, waterlogged, saline soils. Another notable feature of a few mangrove plants, particularly in the Rhizophoraceae and Acanthaceae families, is vivipary, where seeds germinate while still attached to the parent plant. Some mangrove species prevent salt from entering their roots, while others excrete salt through specialised glands. Mangrove ecosystems support biodiversity, with 341 threatened species that rely on these habitats. They support the livelihoods of 4.1 million small-scale fishers globally. Mangrove ecosystems reduce disaster risks effectively than artificial barriers in dissipating wave energy, trapping sediment, reducing erosion, and stabilising shorelines (Schoonees et al., 2019; Karimi et al., 2022). The mangrove forests and certain other coastal vegetation can significantly mitigate the impact of tsunamis on coastlines (Hiraishi, 2003). Few analytical models suggest that a density of 30 trees per 100 m² in a 100-meter-wide belt could reduce tsunami waves up to 90% (Hiraishi and Harada 2003), suggesting that these coastal bioshields are both sustainable and more cost effective compared to artificial barriers such as sea walls and groins (Hiraishi and Koike 2001;Hiraishi 2003). Mazda et al. (1997) observed the effectiveness of mangrove forests in coastal protection in Vietnam. Kelty et al. (2021) demonstrated that dense and healthy mangrove forests can significantly mitigate the impacts of tsunamis. The dense aboveground mangrove canopy and robust root structure influence wave attenuation, slowing water flow and dissipating wave energy (Gijsman et al., 2021). Studies proved that mangroves can attenuate wind and swell waves under 70 cm in height by 50% to 99% across a 500-meter-wide mangrove forest (Quartel et al., 2007; Vo-Luong and Massel, 2008; Bao, 2011). The Rhizophora mangrove forests reduced the impacts of hurricanes by up to 24% where the mangrove forests were less than 1 km wide, while more extensive mangrove areas were relatively unaffected (Del Valle et al., 2020). Several factors affect wave height as waves pass through mangroves, including water depth, wave height, mangrove species, tree age and size (McIvor et al., 2012). The surface waves travelling through a mangrove forest experience significant energy loss due to two primary dissipation mechanisms: multiple interactions with mangrove trunks and roots, and bottom friction. Projected sea level rise (0.26 m to 0.98 m by 2100) is likely to aggravate storm impacts by accelerating flooding in the low-lying areas (Jones et al., 2021). However, mangrove ecosystems can trap sediments and grow vertically reducing the effects of rising sea levels. Given the right sediment type, Chow (2018) noted that mangroves can proliferate and mitigate the impacts of sea level rise. |
Citation Key | 1056 |