Mangrove Forests Dr. James A. Danoff-Burg Columbia University James A. Danoff-Burg, Columbia University, jd363@columbia.edu

Mangrove Forests Found in coastal areas all over the tropics Primarily in brackish water salty and fresh mix Cover approximately 22 million hectares in tropical and subtropical coasts James A. Danoff-Burg, Columbia University, jd363@columbia.edu

Ecosystem Functions & Threats Serve as an important buffer between sea and land Lessen impact of intense storms Reduce erosion and increase sedimentation Important coastal pioneer species Act as basis for a complex, biologically diverse, and productive ecosystem Increasingly threatened Human development is most intense along coasts James A. Danoff-Burg, Columbia University, jd363@columbia.edu

Mangroves Not a natural taxonomic group Convergence among several groups Possibly 16 convergent events Based on physiological attributes 54 species total world-wide 16 Families Principally: Avicenniaceae & Rhizophoraceae These two families include 25 spp. 20 Genera James A. Danoff-Burg, Columbia University, jd363@columbia.edu

Mangrove Location Found in tropical areas only Within the 20ºC isocline More southern on East side of continents Due to southward moving warm Equatorial currents there James A. Danoff-Burg, Columbia University, jd363@columbia.edu

Terminology Mangal Mangrove Pneumatophore Community of organisms in the mangrove habitat Mangrove Trees that flourish in the mangal Pneumatophore Vertical root structures for air exchange Lenticels - tiny pores for air exchange Aerenchyma – tissue for air storage James A. Danoff-Burg, Columbia University, jd363@columbia.edu

Characteristics of Mangal Inundation with tides Increasing salinity towards ocean Sandy clay soil Nutrient poor Nitrogen & Phosphorus are limiting Limiting mangrove growth only Organic nutrients deposited via siltation Fresh water streams & down-shore currents Most all are of terrestrial origin In sum: Mangal is a harsh place to live James A. Danoff-Burg, Columbia University, jd363@columbia.edu

Mangrove Adaptations Salt tolerance Frequent inundation Sequester in tissue (bark, stem, root) Secrete through leaves Exclusion by negative hydrostatic pressure Frequent inundation Aerenchyma tissue & aerial roots Tolerant of soils low in oxygen Hypoxic or anoxic James A. Danoff-Burg, Columbia University, jd363@columbia.edu

Mangrove Consequences of Adaptations Greater root mass Relative to rest of plant & relative to non-mangrove species For water exchange & air exchange Lower growth rates Consequence of salt & air exchange Tradeoff between salt tolerance & frequent inundation Can adapt for one or other Not both James A. Danoff-Burg, Columbia University, jd363@columbia.edu

Mangrove Pollination Pollination method varies by species Wind (Rhizophora) bat or hawk moth (Sonneratia) birds and butterflies (Bruguiera) bees (Acanthus, Aegiceras, Avicennia, Excoecaria, Xylocarpus) fruit flies (Nypa) other small insects (Ceriops, Kandelia) James A. Danoff-Burg, Columbia University, jd363@columbia.edu

Mangrove Reproduction Vivipary normal Reproduction and growth while still attached to plant Flowering Fertilization Propagule growth Mature propagule Young propagule a.k.a. Hypocotyl James A. Danoff-Burg, Columbia University, jd363@columbia.edu

Mangrove Dispersal Maturity -> Drop off maternal plant Float horizontally initially Dispersal to novel environments ideally Float vertically with appropriate environmental conditions Rooting and growth James A. Danoff-Burg, Columbia University, jd363@columbia.edu

Mangal Habitat Types (from inland to oceanfront) Riverine Often found in river deltas Constant influx of freshwater Great changes in salinity levels Basin Mangroves Inland, behind coastal mangroves Little change in tides, no wave action Often higher salinity than others (evaporation) Tide-Dominated Coastal front habitats Frequent sedimentation Unstable morphology due to coastal erosion James A. Danoff-Burg, Columbia University, jd363@columbia.edu

Intraspecific Differences in Environmental Tolerances Salinity variations and adaptations for excreting salt Varies within and between species Through growth stages Tidal Inundation and adaptations for gas exchange Pneumatophores and other aerial root extensions Low soil stability, Shore morphology, and adaptations for rooting Prop Roots Sedimentation rates and types James A. Danoff-Burg, Columbia University, jd363@columbia.edu

Mangrove Species Zonation Bruguiera gymnorrhiza Ceriops australis Rhizophora stylosa Avicennia marina All increase toward shore Salinity Inundation Decreasing Soil Stability Sedimentation Rate James A. Danoff-Burg, Columbia University, jd363@columbia.edu

Most Common Species Red Mangrove (Rhizophora mangle) Black Mangrove (Avicennia germinans) White Mangrove (Laguncularia racemosa) All are found throughout tropics James A. Danoff-Burg, Columbia University, jd363@columbia.edu

Bark Identification James A. Danoff-Burg, Columbia University, jd363@columbia.edu

Tree Characters James A. Danoff-Burg, Columbia University, jd363@columbia.edu

Pneumatophores James A. Danoff-Burg, Columbia University, jd363@columbia.edu

Epiphytes James A. Danoff-Burg, Columbia University, jd363@columbia.edu

For more information Go to http://www.earthisland.org/map/mngec.htm and read the ecology link A clearinghouse on information on mangrove ecology is available at http://www.ncl.ac.uk/tcmweb/tcm/mglinks.htm James A. Danoff-Burg, Columbia University, jd363@columbia.edu

Mangroves of Australia The mangrove plants of Queensland (from http://www.aims.gov.au/pages/reflib/fg-mangroves/pages/fgm-qld-15.html) Listed below are the true mangrove species that grow in Queensland. Hybrid plants are indicated by the use of an x in the scientific name (e.g. Lumnitzera x rosea). AcanthaceaeAcanthus ebracteatus Acanthus ilicifolius ArecaceaeNypa fruticans AvicenniaceaeAvicennia marina BignoniaceaeDolichandrone spathacea BombaceaeCamptostemum schultzii CaesalpiniaceaeCynometra iripa CombretaceaeLumnitzera racemosa, Lumnitzera x rosea, Lumnitzera littorea EbenaceaeDiospyros ferrea EuphorbiaceaeExcoecaria agallocha LythraceaePemphis acidula MeliaceaeXylocarpus granatum MyrsinaceaeXylocarpus mekongensis, Aegiceras corniculatum MyrtaceaeOsbornia octodonta PlumbaginaceaeAegialitis annulata PteridaceaeAcrostichum speciosum RhizophoraceaeBruguiera gymnorrhiza,Bruguiera sexangula, Bruguiera exaristata, Bruguiera parviflora, Bruguiera cylindrica, Ceriops australis, Ceriops decandra, Ceriops tagal, Rhizophora apiculata, Rhizophora x lamarckii, Rhizophora stylosa, Rhizophora mucronata RubiaceaeScyphiphora hydrophyllacea SonneratiaceaeSonneratia alba, Sonneratia x gulngai, Sonneratia caseolaris, Sonneratia lanceolata SterculaceaeHeritiera littoralis James A. Danoff-Burg, Columbia University, jd363@columbia.edu