Process of succession in hydrosere.

Such water sources in Nepal are lots likewise, ponds, rivers, lakes and mountainers. These sources of water make the Nepal 2nd riches of water sources in the World. But Unfortunate Nepal still can't get success to utilize and the reason effects directly develop on country region.The process of succession occuring in water mass like ponds, pools or lakes is known as hydrosere. In pond, phytoplanktons (cyanobacteria, algae, diatoms and bacteria) are the pioneers to be invade in the early pond water. These phytoplanktons are consumed by zooplanktons (protozoans) or by smaller fishes etc. which after their death increase the organic content in the pond. These are decomposed by fungi and bacteria and the nutrients are released which supports the growth of rooted submerged hydrophytes (Hydrilla, Chara, Vallisneria, Utricularia, etc.) in the shallow water zone. The hydrophytes as well as submerged animal die and are decomposed by microbes thereby releasing nutrients. In due course of time, due to accumulation of organic matters and silting process water depth of pond is reduced and at the margin or edges there grow some rooted floating plants like Nymphaea, Nelumbo, trapa, etc and floating animals like Hydra, insect larvae, etc. Gradually the water depth is further decreased if drought or high evaporation rate occurs due to intense sun light but deposition of organic matters and concentration of nutrients increases. Then some freely floating plants like Azolla, Salvinia, Pistia, etc. increase in number in such condition of high nutrients. Gradually dead bodies increase in the pond resulting further build up of the substratum, ponds become further shallower. Ath this stage the pond becomes swampy so amphibious species such as Typa, Rumex, Sagittaria, etc. appear with roots in water and shoot are exposer to air.
             If water level further decreases then the conditions become unfavourable for the growth of amphibious species and favourable for plant of Cyperaceae, Graminae (e.g. Juncus, Cyperus, etc.). These plants are then replaced by mesic (moderately moist habitat) communities. As the soil becomes further drier for most of the time of year, then terrestrial plants like Salix, Cornus, etc. grow and the soil favours the growth of trees like Alnus, Populus etc. woodland community appear by the time there is much collection of humus with microbes and tree species in the area. Woodland community develops into the forest community which is the climax stage.