1. MANGROVES
True mangroves (sensu Tomlinson 1986) are tropical trees restricted to intertidal and adjacent communities, growing in saline, generally anoxic soils, under climatic conditions characterized by a combination of high temperature and irradiance (Stewart and Popp 1987)
Mangrove forests constitute the sea-land interface in all tropical and subtropical coastlines protected against wave impact, and without frost
Mangrove forests play critical roles in coastal biological productivity, coastal protection, and processing of organic matter transported in terrestrial run-off

2. - Mangroves are typical halophytes developing up to reproductive stage in sea water, accumulating large amounts of sodium chloride in their cell vacuoles (Walter and Steiner 1936)
- Salt, water, and energy balances, constitute simultaneous constraints for mangrove photosynthetic productivity, particularly in mangal habitats where supply of fresh water through rainfall or riverine flow is restricted
- Nutrient supply modulates the responses of mangroves to environmental stresses (Boto 1983)
- Nutrient supply to mangrove ecosystems is predominantly associated with terrestrial drainage,comparatively richer than sea water (Lugo et al. 1976)

3. Asimetric distribution of mangrove forests in South America
Along the western coast the Humboldt current transports cool waters northwards causing lack of rain. Along the east coast warm equatorial Atlantic water flow southwards

4. requirements of saline environments (from Tomlinson 1986)
Family and Genera No. of species American species
Avicenniaceae
Avicennia A. germinans
A. schaueriana
A. bicolor
Combretaceae
Laguncularia 1 L. racemosa
Lumnitzera 3
Conocarpus C. erectus
Meliaceae
Xylocarpus 3
Myrsinaceae
Aegiceras 2
Pellicieraceae
Pelliciera P. rhizophoreae
Plumbaginaceae 2
Aegialitis
Rhizophoraceae
Bruguiera 6
Ceriops 2
Kandelia 1
Rhizophora R. mangle
R. racemosa
Sonneratiaceae
Sonneratia 5
Total: 13 genera species 8 American species
Families and genera of true mangroves based on their distribution and apparent
requirements of saline environments (from Tomlinson 1986)

5. Types of aerial root systems in strict mangroves (Gill and Tomlinson 1975)
Morphological adaptations of the Mangrove genera
root system to flooding
Stilt roots Rhizophora, Bruguiera, Ceriops
Avicennia (sporadically)
Pneumatophores Avicennia, Sonneratia,
Laguncularia (facultative)
Root knees Bruguiera and Ceriops
Lumnitzera, Xylocarpus
Plank roots Xylocarpus
Fluted buttresses Pelliciera
Without special aerial roots Aegiceras, Aegialitis, Kandelia

6. Samples from natural mangrove communities in the Caribbean

7. Bruguiera gymnorrhiza Avicennia marina Lumnitzera racemosa
Leaf anatomy of mangroves showing thickness of “water parenchyma” (Walter and Steiner 1936)
Sonneratia alba
Rhizophora mucronata
Ceriops tagal
Bruguiera gymnorrhiza
Avicennia marina
Lumnitzera racemosa D F E
0.2 mm

8. Accumulation of ions in leaves is compensated by simultaneous water uptake: ion concentration per unit leaf area increases as the leaf ages, but the ion concentration pero unit tissue water remains constant

9. Differential accumulation of ions in leaf tissues of R.m.
(after Werner & Stelzer 1990)
Upper epidermis
Differential accumulation of ions in leaf tissues of R.m.
Upper hypodernis
Mesophyll
Lower hypodermis
Lower epidermis

10. Concentration of salt in xylem sap (Scholander et al. 1962)
NaCl g l-1 Leaves with salt
secreting glands
Rhizophora mucronata
Sonneratia alba
Bruguiera cf. exaristata
Aegiceras corniculatum
Avicennia marina
Aegialitis annulata
Species

11. Selectivity ratios (SK.Na = (Ktissue/Natissue)/(Kcult.solution/Nacult.solution) in leaf and root tissues of Avicennia marina and Rhizophora stylosa cultivated under different salinities (from Clough 1984)
Species and tissue SK.Na
% sea water
Avicennia marina
leaves
roots
Rhizophora stylosa
leaves
roots

12. Concentration of organic solutes of low molecular weight in mangroves (from Stewart and Popp 1987)
Species Solute mol m-3 tissue water
Aegialitis annulata pinitol chiroinositol 150
proline
Aegiceras corniculatum mannitol
Avicennia marina glycinbetaine
Bruguiera gymnorrhiza 1D-1-O-methyl-muco-inositol
Ceriops tagal 1D-1-O-methyl-muco-inositol 150
Lumnitzera littorea mannitol
Rhizophora apiculata 1D-1-O-methyl-muco-inositol 220
Sonneratia alba mannitol
Xylocarpus mekongensis proline

15. Variation in the leaf inclination with the degree of exposure in five mangrove species in Hinchinbrook Island, North Queensland (Ball et al. 1988). (The projected fraction of leaf area= cos a, where a is the angle of the leaf respective to the horizontal; exposure is expressed as shade (Sh), medium sun (MS), and full sun (FS)
Species Exposure Leaf Area Projected Succulence
(cm2) fraction (g m-2)
B. gymnorrhiza Sh ± ± ± 8.0
MS ± ± ± 35.4 FS
R. apiculata Sh ± ± ± 21.9
MS ± ± ± 16.8
FS ± ± ± 41.1
R. stylosa Sh ± ±
MS ± ± ± 11.2
FS ± ± ± 35.5
C. tagal Sh ± ± ± 9.2
MS ± ± ± 33.9
FS ± ± ± 55.4

16. Variations of apparent quantum yield of leaves grown under full exposure or partial shade of mangrove species on northern Australia (Björkman et al. 1988)
Species Exposure  f O2
(mmol O2 mol-1 photons)
Aegialitis annulata Partial shade
Exposed
Aegiceras corniculatum Shade
Exposed
Avicennia marina Partial shade
Exposed
Rhizophora stylosa Partial shade
Exposed
Sonneratia alba 80º leaf angle
47º

17. Optimum salinity for mangrove growth (Clough et al)

18. Range of water utilization in marine coastal mangroves in Florida (Sternberg)

19. Decrease in leaf area associated with osmotic concentration of leaf sap

20. Decrease of leaf conductance of several Rhizophora species in relation to salinity of water at the root level (Clough et al.)

21. Light dependence of CO2 uptake of mangrove species growing in hypersaline(Tacuato) and low (Ricoa) salinity sites (Watzka 1999)

22. Mangrove occurrence in wet and dry coastal habitats
(after Walter & Steiner 1936)

23. Leaf characteristics of mangrove species from humid and dry habitats in north-eastern Venezuela
Species Habitat Area SLA Osmolality Nitrogen Chlorophyll d13C
cm m2 kg mmol kg ‰
Laguncularia Humid (2.5) 7.8 (0.4) 957 (52) 906 (43) 3.2 (0.2) (0.2)
racemosa
(n=16-2) Dry (9.4) 5.7 (0.4) (42) 864 (76) 2.3 (0.5) (0.6)
p= 0.05* ** **
Rhizophora Humid (4.7) 6.5 (0.3) 1068 (38) 960 (46) 3.3 (0.3) (0.4)
racemosa +
mangle Dry (5.3) 5.3 (0.3) 1558 (64) 895 (82) 1.9 (0.4) (1.1)
(n=17- 4)
p= ** ** * 0.693
Avicennia Humid (6.0) 9.2 (0.4) 1253 (103) 1720 (143) 4.4 (0.4) (0.5)
germinans
(n=8-8) Dry (2.8) 6.8 (0.4) 1762 (141) 1488 (116) 3.4 (0.4) (0.3)
p= ** ** 0.012* **

24. Seasonal variations of gas exchange characteristics, cell sap osmolality and Na+ and Cl- content in Avicennia germinans and Conocarpus erectus growing in salt flats (From Smith et al. 1989). * Photosynthetic active radiation > 1 mmol m-2 s-1
Avicennia germinans Conocarpus erectus
Rainy season Dry season Rainy season Dry season
Osmolality (mmol kg-1)
Cl- (mol m-3) Na K
Na+/K
Photosynthetic rate near
saturation * (µmol m-2 s-1)
Total net CO2 uptake during the
light period (mmol m-2 12 h-1)
Total transpiration per light
period (mol H2O m-2 12 h-1)
Water-use efficiency during the
light period
mol CO2 mol-1 H2O x 10-3

25. Dwarf and scrub mangroves: Salinity vs Nutritional Stress
Dwarf mangrove forests of Rhizophora mangle in the Caribbean are associated to low availability of P (Feller 1995)
Scrub mangrove communities of Avicennia germinans occur in low rainfall areas with interstitial water salinities 2-3 times larger than sea water

26. Nutrient concentrations (mmol m-2) of fresh leaves of Rhizophora mangle after two years of fertilization with NPK (10:15:15 as NH4:P2O5:K2O), P (0:45:0 as P2O5); N (45:0:0 as NH4(SO4)2) (Data modified from Feller 1995)
Nutrient NPK P N Control C N P K Ca Mg Na
Leaf-water
g m-2
Leaf A/W
m2 kg-1

27. Thickness (µm) of tissue layers of leaves in basal and penapical stem positions on fertilized Rhizophora mangle trees after two years of specified treatments. In a row * numbers are significantly different from control (Feller 1996)
Fertilizer treatments
Leaf-tissue layers NPK P N Control
Penapical leaf
Cuticle
Upper epidermis
Hypodermis * 231*
Palisade mesophyll
Spongy mesophyll
Basal leaf
Cuticle
Upper epidermis
Hypodermis * 594*
Palisade mesophyll
Spongy mesophyll * 236*