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8/12/14! Mangroves - - a - plants that grow in tidal areas! mangrove can describe a single plant or it can refer to! whole community of plants! halophytes! Mangal Distribution! What can you infer about mangroves just by looking at their distribution?! !1 8/12/14! General Characteristics! 1. Species restrictions 2. Community structure 3. Morphological specializations 4. Exhibit salt- exclusion physiology 5. Taxonomic isolation Mangrove Forest Classification! occur in a depression, connected to streams or tidal creeks! along streams and rivers, may extend several miles inland! inland wetlands, fw isolated! severe abiotic conditions are severe, limited water! low intertidal! along protected shorelines! 2! 8/12/14! So, overall, where do Mangroves grow?! - best in sheltered areas with! low wave energies ! = high wave energies destroy! shallow root systems, prevent! seedling establishment ! - build up of fine sediments! needed for growth! So, what effects will human impacts and severe natural conditions (which could be what?) have on mangrove environments?! Adaptations of Mangroves! 1. Mechanical adaptations! 2. Aerial roots= common & specialized! ! ! 3. Vivipary= germination of seedlings! ! ! 4. Seeds & seedlings = survive in & disperse! ! 5. Xerophytic modifications! ! 6. Halophytic modifications! 3! 8/12/14! Adaptations:! Mangrove Leaves! evergreen! thick outer walls & cuticles! salt is accumulated in leaves = salt glands = succulence! glandular hairs- function in salt excretion! lenticles- cork warts secrete water & chloride ! hypodermis = tannins! lower layer = hydrocytes = water containing cells! Adaptations: Mangrove Trunks & Bark! ! Lenticles = dense masses of cells that results in breaks in the bark = cork warts! - function in gas exchange! - critical for root survival! 4! 8/12/14! Mangrove Root Types! unusual root system = stability in loose soil, oxygen intake! Mangrove Zonation! Upper limit Lower limit 5! 8/12/14! Rhizopora mangle - Red mangrove! red bark ! leathery leaves = dark green, pale underneath! vivipary = seedling germinate from fruit while! !attached to tree! stilt roots - prop roots, air supply to underlying roots, develop from seed and grow downward! lacunae - gas exchange! closest to water = highest salt tolerance! Avicennia germinans - black mangrove black/brown bark! hair on leaves- salt secretion! cryptovivipary - embryo grows out of the seed but not the fruit! aerenchyma tissue- gas exchange! cable root with pneumatophores- extend 10-20 cm above root, function in gas exchange! 6! 8/12/14! Avicennia marina - white mangrove! pale bark! stilt or cable roots = no prop roots or pneumatophores! nectaries at base of leaves secrete sugar! hair on leaves - salt secretion! generally live upland from red and black mangroves! Mangal Macroalgae important primary producers epiphytic algae on roots = to the leaf litter from the tree 7! 8/12/14! ! Ecological Roles of Mangals! ! ! 1. Filtering land runoff! 2. Stabilization of sediments! 3. Trapping sediments, leaf detritus! 4. Primary Production! 5. Habitats! Loss of Mangals! ! Extraction, pollution and coastal development! ! Has lead to declines of finfish & commercial shrimp! ! Long term pollution from oil spills cause mutations in the trees! 8!
