Mangroves

Extract

[...] The emblematic mangrove tree is the mangrove. This term conceals several families of macrophytes which, thanks to a mechanism of evolutionary convergence, are all adapted to the living conditions of mangroves (Taureau, 2017). To survive in a salty environment, some species use high osmotic pressure to expel salt through their roots. Others accumulate salt in certain leaves that are sacrificed, or have salt glands at the base of the leaves (Taureau, 2017). To survive immersion, the reproductive system has also adapted to allow fruit to be transported by water (Taureau, 2017). [...]

[...] (2014) that mangroves act as an environmental buffer, notably by reducing temperature, the main factor affecting the development of invertebrates. The animal biodiversity of mangroves is therefore highly dependent on neighbouring ecosystems. But species have had to adapt to these particular living conditions. Vertebrates have adapted to salinity by developing nasal glands and skin pores that restrict exchanges (Luther and Greenberg, 2009). Morphological changes have been made in terrestrial species to adapt to aquatic life: birds, for example, tend to have longer, narrower beaks (Luther and Greenberg, 2009). [...]

[...] Abiotic parameters governing ecosystem equilibrium Mangroves are subject to particular climatic factors. Firstly, they are subject to rapid fluctuations in temperature (Hendy et al., 2014). Light levels vary according to the closure of the canopy (Taureau, 2017). Secondly, their location between land and sea means that they experience alternating immersion and emersion, and therefore strong variations in salinity, hydromorphy (also variable according to rainfall, which is also a vector of biodiversity in mangroves (Le Loeuff, in Cormier-Salem, 1999)) and anoxia (Guiral, in Cormier-Salem, 1999). [...]

[...] The animal biodiversity of mangroves is characterised by various metazoans. First of all, there is an epifauna thanks to the mangroves, with sponges in particular. The sub-decade Eumetazoa includes the phylum Cnidaria (Myxozoa cited by Knockaert et al. (2019)). The sub-region Bilaterians includes: - for the infra-region of Protostomians, the sub-branch of Crustacea (super-branch of Ecdysozoa, phylum of Arthropoda) represented by the class Malacostraca (Isopoda, Mysidacea, Decapoda and Amphipoda cited by Cormier-Salem (1999)) and that of Maxillopoda (Copepoda and Cirripoda cited by Cormier-Salem that of the Molluscs (super-branch of the Lophotrochozoans) including gastropods and bivalves (Le Loeuff, in Cormier-Salem, 1999) including the mangrove oyster, Crassostrea cucullata (Knockaert et al. [...]

[...] It also serves as a nursery. In this way, the biotic hydric factor influences the presence of Teredinidae, since they are less present in mangroves exposed to long emergence times, and the latter in turn modify the conditions of temperature, humidity and supply of organic matter. This also has impacts on neighbouring ecosystems by exporting nitrogen and carbon from the mangroves via processed wood associated with tissues and faeces (Hendy et al., 2014). We could also mention crabs, which play a role in the mechanical fractionation of organic matter and the oxygenation of sediments when they dig their burrows (Guiral, in Cormier-Salem, 1999). [...]