Botany

• Mangroves


  Referred to as "mangals," "coastal woodlands," "tidal forests," and many more
• Mangroves


  • Littoral plant formations
  • Salt-tolerant woody plants that form low-diversity forests with complex food webs and ecosystem dynamics
• There are 80 described mangrove species
• Mangroves evolved


  114 million years ago
• The Indo-Malaysian region is considered the cradle of evolution of the mangrove ecosystems
• Mangroves originated in Southeast Asia and have been dispersed to India, Africa, Australia, and the Americas by ocean currents over millions of years
• Salt filtration


  Some mangrove species filter out salt at the root level and prevent most of it from entering the plant; they can exclude up to 90% of the salt from the seawater they absorb
• Water retention in leaves

  A method used by several mangrove species to dilute the salt they absorb
• Mangrove roots


  • Specialized roots that allow them to live in an oxygen poor sediment
  • Poorly developed below-ground root system but well developed Aerial Roots
  • Aerial Roots have pores called LENTICELS to allow the entry of oxygen
• Salt exclusion


  Mangroves have specialized roots that filter the salt concentration of seawater by taking up water but preventing entry of salt through root filtration
• The red mangrove is an example of a salt-excluding species
• Mangrove species in the Philippines

  • Major mangroves
  • Minor mangroves
• The Philippines holds at least 50% of the world's approximately 65 mangrove species
• Spalding (2010) reported 73 mangrove species (inclusive of hybrids) in which 38 were called core species
• All around the world, mangroves are referred to as "mangals," "coastal woodlands," "tidal forests," and many more. They are littoral plant formations.
• There are 80 described mangrove species. They are salt-tolerant woody plants that form low-diversity forests with complex food webs and ecosystem dynamics
• The Indo-Malaysian region is considered the cradle of evolution of the mangrove ecosystems
• It is a wide-spread belief that mangroves originated in Southeast Asia, and have been dispersed to India, Africa, Australia, and the Americas by ocean currents over millions of years
• Mangroves


  • They live in hostile environments with harsh conditions like high salinity, hypoxic (low oxygen)/waterlogged soil substrate, tidal pressures, etc.
• Salt filtration


  Some mangrove species filter out salt at the root level and prevent most of it from entering the plant; they can exclude up to 90% of the salt from the seawater they absorb
• Salt filtration


  • Rhizophora, Ceriops, Bruguiera
• Water retention in leaves

  A method used by several mangrove species to dilute the salt they absorb
• Water retention in leaves

  • Sonneratia apetala, Lumnitzera recemosa
• Salt glands


  The leaves of many mangrove species have special salt glands that actively secrete salt. Crystallized salt can sometimes be seen on the leaf surface.
• Salt glands


  • Avicennia, Sonneratia, Acanthus
• Salt deposition


  Some species deposit and concentrate the salt in the bark or in older leaves, which will soon detach and drop, bringing the salt with them when they do.
• Salt deposition


  • Lumnitzera, Avicennia, Ceriops, Sonneratia
• Aerial roots


  • Mangroves have specialized roots that allow them to live in an oxygen poor sediment. They have well developed aerial roots with pores called lenticels that allow the entry of oxygen.
• Aerial roots


  • Stilt roots, Pneumatophores, Knee roots
• Salt exclusion


  Mangroves have specialized roots that filter the salt concentration of seawater. They take up water but prevent the entry of salt through root filtration. Root membranes prevent salt from entering while allowing water to pass through.
• Salt exclusion


  • The red mangrove is an example of a salt-excluding species.
• Salt extrusion


  Mangroves get rid of stored salts by shedding via leaves, bark, or roots. They take up salt water and secrete salt.
• Salt extrusion


  • Salt secretion in leaves
• The Philippines is considered one of the top 15 most mangrove-rich countries in the world
• The Philippines holds at least 50% of the world's approximately 65 mangrove species
• It is difficult to resolve the issue of the exact number of mangrove species recognized worldwide due to taxonomic inconsistencies
• 11 true mangrove species in the Philippines qualified for the IUCN Red List categories of threat including two critically endangered, three endangered, and six vulnerable species
• Not a single mangrove species is included in the National Red List crafted by the Philippine Plant Conservation Committee
• Despite widespread knowledge of their value, mangroves are being lost globally at a mean rate of 1-2 per cent per year
• The global rate of mangrove loss has been declining over the last three decades