575
Mangrove communities, with their unique adoptive features form different zonations, according to physiography, topography, tidal inundations, salinity regimes
etc. Each species of mangroves has its own solutions to cope with the problems of
anoxia, high salinity and frequent tidal inundation. This may also be the reason why
on some coastlines mangrove tree species show distinct zonations. Small variations
within a mangal may lead to highly varying methods for coping with the environment. Therefore, the mix of species is partly determined by the tolerance of the
individual species to the prevailing physical conditions, such as salinity, tidal inundation, but may also be influenced by other factors such as predation of plant seedlings by crabs.
19.1.1 Importance of Mangroves
Mangroves perform many important functions in the context of the coastal and
marine environment as well as provide vital and unique ecosystem goods and services to the human society. It helps in reduction of coastal erosion, stabilizing the
shore-lines and protecting the coast by acting as wind breakers and barriers against
storm surges and heavy tides (Bahuguna et al. 2008; Giri et al. 2007; Kathiresan and
Rajendran 2006; Dahdouh-Guebas et al. 2005). Its massive root systems are efficient at dissipating wave energy. Mangrove forest play important role in transferring
organic matter and energy from the land to marine ecosystem through the detritus
from the fallen leaves and branches. Bacteria breaks down the detritus, releasing
useful nutrients in to water and thus forms the base of the highly productive marine
food chain. The dense root system forms a home for fish, crabs, shrimps and mollusc. They also serve as nursery grounds for the larvae and juveniles of marine
inhabitants. In addition, mangrove forests are nesting and migratory sites for a large
number of bird’s species as well as home to a variety of reptile, amphibian and
mammal species. For example, the Sunderbans mangroves are the home to Bengal
tigers, spotted deer, saltwater crocodiles, fishing cats and several dolphin species.
Mangroves also contribute to the livelihood of coastal people in terms of forest
produce and fishery resources. A balance exists between the complex biological
system of mangrove forests and the local people who exploit the system without
destroying it. In addition to serving as a habitat to support the faunal biodiversity in
the coastal areas, mangrove wetlands also serve as potential recreation site for fishing, boating, bird watching, sightseeing and photography. Mangroves are selfgenerating, self-perpetuating and highly resilient littoral formations, playing a
major role in the global cycle of carbon, nitrogen and sulphur. They act as sink for
detritus and sediments draining from coastal catchments and help in territory assimilation of waste.
The exact number of mangrove species is still a matter of debate and ranges from
50 to 70 according to different classification systems (Spalding et al. 2010; FAO
2007; Aksornkoae et al. 1993; Tomlinson 1986; Saenger et al. 1983; Lugo and
Snedaker 1974), with the highest species diversity found in Asia, followed by
19 Mangrove Inventory, Monitoring, and Health Assessment
Mangrove communities, with their unique adoptive features form different zonations, according to physiography, topography, tidal inundations, salinity regimes
etc. Each species of mangroves has its own solutions to cope with the problems of
anoxia, high salinity and frequent tidal inundation. This may also be the reason why
on some coastlines mangrove tree species show distinct zonations. Small variations
within a mangal may lead to highly varying methods for coping with the environment. Therefore, the mix of species is partly determined by the tolerance of the
individual species to the prevailing physical conditions, such as salinity, tidal inundation, but may also be influenced by other factors such as predation of plant seedlings by crabs.
19.1.1 Importance of Mangroves
Mangroves perform many important functions in the context of the coastal and
marine environment as well as provide vital and unique ecosystem goods and services to the human society. It helps in reduction of coastal erosion, stabilizing the
shore-lines and protecting the coast by acting as wind breakers and barriers against
storm surges and heavy tides (Bahuguna et al. 2008; Giri et al. 2007; Kathiresan and
Rajendran 2006; Dahdouh-Guebas et al. 2005). Its massive root systems are efficient at dissipating wave energy. Mangrove forest play important role in transferring
organic matter and energy from the land to marine ecosystem through the detritus
from the fallen leaves and branches. Bacteria breaks down the detritus, releasing
useful nutrients in to water and thus forms the base of the highly productive marine
food chain. The dense root system forms a home for fish, crabs, shrimps and mollusc. They also serve as nursery grounds for the larvae and juveniles of marine
inhabitants. In addition, mangrove forests are nesting and migratory sites for a large
number of bird’s species as well as home to a variety of reptile, amphibian and
mammal species. For example, the Sunderbans mangroves are the home to Bengal
tigers, spotted deer, saltwater crocodiles, fishing cats and several dolphin species.
Mangroves also contribute to the livelihood of coastal people in terms of forest
produce and fishery resources. A balance exists between the complex biological
system of mangrove forests and the local people who exploit the system without
destroying it. In addition to serving as a habitat to support the faunal biodiversity in
the coastal areas, mangrove wetlands also serve as potential recreation site for fishing, boating, bird watching, sightseeing and photography. Mangroves are selfgenerating, self-perpetuating and highly resilient littoral formations, playing a
major role in the global cycle of carbon, nitrogen and sulphur. They act as sink for
detritus and sediments draining from coastal catchments and help in territory assimilation of waste.
The exact number of mangrove species is still a matter of debate and ranges from
50 to 70 according to different classification systems (Spalding et al. 2010; FAO
2007; Aksornkoae et al. 1993; Tomlinson 1986; Saenger et al. 1983; Lugo and
Snedaker 1974), with the highest species diversity found in Asia, followed by
19 Mangrove Inventory, Monitoring, and Health Assessment