SOIL EROSION AND SILTATION |
Solutions to this part of soil erosion problem may come from searching for suitable plants that could grow well at aforesaid ecotone. In estuarine wetlands this problem is even more severe than inland reservoirs because of stronger wave action. However, nature has a solution in the form of mangrove vegetation. Experiments with available and speculated-to-be suitable plant species can be tried.
Species like Ipomoea carnea, Ipomoea biloba, Ipomoea aquatica, Saccharum sps, Terminalia arjuna, many other aquatic and semi-aquatic plants (creepers-cum-floaters), Cyperus species etc can also be tried. The riverbeds of fluctuating water levels could be looked for suitable plant species. Even mangrove plants like Clerodendron inerme, Ipomoea biloba, Derris sp., etc. could be tried. The difference between estuarine wetlands and the reservoirs is that mangrove plants have a very long evolutionary history compared to the plants interacting with inland reservoirs. This is because the dams and reservoir (wetlands with highly fluctuating water level) are of recent origin from the point of view of evolutionary time scale. Flood-tolerant species like Holigarna, Madhuca neriifolia, Elaeocarus and Pandanus etc can be tried. Among the colonizers on the exposed area below the Full Reservoir Level, three species were noticed besides other plants; these were Cynodon, Eupatorium and Cleome. Even if some species from these plants start growing well in this exposed area, the erosion will reduce. This ecotone zone should be searched whether suitable plants have evolved. Plants suitable for such erosion prone areas may be propagated. Cynodon is good for cattle but here it should not be allowed to be grazed. Eupatorium is a difficult exotic weed and not good except for its low quality biomass. Cleome is a weed as well as a crop. (Please note that no plants can grow in submerged state, except hydrophytes). The others grow seasonally, only when the water level goes down. Grasses are the best option, because of their spreading nature).
