An ecological assessment of coastal vegetation along the Gulf of Guinea highlights specific environmental stressors, including unstable muddy substrate, periodic anaerobic waterlogging, and high ambient salinity. Which combination of anatomical and physiological adaptations enables the red mangrove (*Rhizophora racemosa*) to establish dominance in the intertidal mangrove swamp biome of southern Nigeria?
- Stilt roots for mechanical support in soft mud, pneumatophores with lenticels for aerial gaseous exchange, and root cell membranes capable of ultrafiltration to exclude saltAnswer
- BDeep subterranean taproot systems reaching freshwater aquifers, reduced microphyllous leaves with sunken stomata, and stem bark that secretes excess sodium chloride
- CNon-lignified stem tissues for extreme flexibility, finely dissected submerged leaves for dissolved gas uptake, and total absence of vascular tissue
- DEpidermal cells capable of bidirectional translocation of mineral salts, feathery aerial roots absorbing atmospheric vapor, and leaf abscission driven by photoperiodism
Answer
Stilt roots for mechanical support in soft mud, pneumatophores with lenticels for aerial gaseous exchange, and root cell membranes capable of ultrafiltration to exclude salt
The red mangrove (*Rhizophora racemosa*) is a dominant plant species in the coastal mangrove biomes of southern Nigeria. It possesses arched stilt roots that anchor the tree firmly in soft, muddy intertidal soils against tidal movements. To overcome the anaerobic (oxygen-deficient) conditions of waterlogged mud, it uses respiratory roots (pneumatophores) covered with lenticels for atmospheric gaseous exchange. Furthermore, ultrafiltration in the root cell membranes prevents high concentrations of salt from entering the vascular system.
Step-by-Step Solution
Key Concept
Structural and physiological adaptations of halophytes in mangrove swamp biomes
Estimated Time:1m 30s