Flowering Plants (Anthophyta) Few truly marine species Seagrasses entirely submerged most of the time; other marine angiosperms intolerant of prolonged immersion Secondary “invaders” of marine ecosystems Expend considerable energy coping with effects of salt water Seagrasses (66 species) Monocots Not true grasses (related to lilies) Hydrophytes (usually immersed) Roots, stems and shoots grow from horizontal rhizome Flowers typically small and inconspicuous (Why?) Pollen carried by water currents (hydrophilous pollination); No need to attract pollinators Highest diversity in Indo-West Pacific (lowest in Atlantic)

Fig. 7-15 - Lacunae: Gas transport and buoyancy - Nodes: Growth and lateral branching Sheath: Protects base of blade Roots: Root hairs for absorption of minerals

Fig. 7-17 Aerenchyme Gas transport Buoyancy Liquid not transported by lacunae Fig. 7-17

Eelgrass (Zostera marina)

Surf Grass (Phyllospadix scouleri)

Turtle Grass (Thalassia species)

Syringodium filiforme Fig. 7-16 Paddle Grass Halophila sp. Fig. 7-16 Leaves cylindrical Manatee Grass Syringodium filiforme Fig. 7-16 Leaves in pairs

Flowering Plants (Anthophyta) Seagrasses Leaves – periods of growth & senescence Small blades/rapid senescence  few epiphytes Large blades/slow senescence  more epiphytes Relatively weak attachment of leaves Protects rhizome from breakage Facilitates recovery following damage from storms, grazing Important in sediment deposition, stabilization Enhance deposition of fine particles Reduce flow, resuspension of sediment Support diverse ecosystem Many species inhabit seagrass beds Below sediment-water interface: rhizosphere Symbiotic associations with lucinid clams (Zostera) Roots oxygenate sediments Clams oxidize sulfide (van der Heide et al. 2012)

Flowering Plants (Anthophyta) Salt Marsh Plants Facultative halophytes Shallow roots and rhizomes Stabilize soils and sediments (esp. grasses & rushes) Cycle nutrients (esp. phosphorus) Food for terrestrial animals Cordgrass (Spartina) Salt-tolerant true grass Salt glands in leaves excrete excess salts Inhabit temperate soft-bottom coastal areas Important sources of Detritus for estuarine food webs Habitat for birds, fishes, etc. Primarily propagate vegetatively backbaybirds.com

Fig. 7-21

Cordgrass (Spartina alterniflora) Fig. 7-19

Flowering Plants (Anthophyta) Salt Marsh Plants Needlerushes Saltworts Glassworts Succulent leaves, cuticle help to retain water Pickleweed (Salicornia) Occurs at higher levels in marsh with less inundation by salt water Edible (sea beans)

Fig. 7-20 Needlerush (Juncus) Saltwort (Batis) Pickleweed (Salicornia) Glasswort (Sarcocornia) Fig. 7-20

Flowering Plants (Anthophyta) Mangroves Salt tolerant shrubs, trees, palms, ferns (54+ species) Tropical terrestrial plants living in protected areas with soft sediments, often organic-rich, anoxic Poor competitors All share certain characteristics Shallow, broad root system and aerial roots with pneumatophores (pores for gas exchange) Salt tolerance (halophytes) Salt exclusion at roots Tough, succulent leaves: thick cuticle, reduced stomata, storage of water & salt, senesce Salt glands: excrete excess salt Viviparity (mainly seaward spp.) Embryo grows on parent plant  propagule Hypocotyl develops, buoyant after separation from parent (red mangroves) Avicennia germinans eolspecies.lifedesks.org

Red Mangrove

Fig. 7-24 Red mangrove - Propagules w/hypocotyl Black mangrove Buttonwood - Floating seeds White mangrove - Floating seeds Fig. 7-24

Flowering Plants (Anthophyta) Mangroves Root systems designed for immersion in soft, anoxic sediments Mostly horizontal, shallow Pores for gas exchange

Black mangrove Red mangrove Fig. 7-22

Red mangrove - Prop root Black mangrove - Cable root Fig. 7-23

Flowering Plants (Anthophyta) Mangroves Mangrove forests = mangals Broad distribution in tropics Co-occur with coral reefs but more tolerant of temperature extremes than hermatypic corals and occur over a wider geographic range Maximum diversity in Indo-West Pacific Some mangals may contain up to 30 species Ten species in New World, three in Florida

Fig. 14-19

Flowering Plants (Anthophyta) Mangroves Mangrove forests (mangals) Extremely productive systems High levels of solar radiation, efficient nutrient recycling Provide important habitat for many spp., including larval and juvenile life stages Protect shorelines against erosion and wave action Create new land Ex: Marco Polo visited port city of Palembang (Sumatra) in 1292 when city was directly on coast - As of 1967, Palembang was 50 km inland, a land accumulation rate of 73 m y-1 over 675 y Ex: Java - Accumulation rates of ca. 200 m y-1 have been reported from Bodri Delta of east Java

Flowering Plants (Anthophyta) Mangroves Mangrove forests (mangals) Horizontal zonation: Transition from terrestrial to marine conditions Onshore-offshore zonation of mangroves also may represent stages in succession from offshore “pioneer zone” with early successional stages to later successional stages onshore

Flowering Plants (Anthophyta) Mangroves Mangrove forests (mangals) Vertical zonation: Transition from canopy to subtidal Above-water forest - Arboreal habitat (birds, reptiles, insects, crustaceans) - Senescing leaves fuel detrital food web Intertidal swamp - Includes mud flats, community shifts with tides - Mobile and sessile epibionts on/in stilt roots Subtidal zone - Burrowing fauna (worms, snails, shrimp, crabs) - Important nursery grounds Caroline Rogers

Fig. 14-24

Mangrove Food Web Fig. 14-22