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Mangroves Ecosystems
IANA F GRULLÓN P
801-09-2856
WEDNESDAY 14 OCT 2015
Mangroves ecosystems Mangroves
Structure
Distribution
Function
Mangroves as sinks
Mangroves as providers
Challenges mangroves ecosystems are facing
Climate change
Mangroves are: “…an assemblage of tropical trees and shrubs that grows in the intertidal zone. Mangroves include approximately 16 families and 40 to 50 species (depending on classification).
(K. McKee, 1996)
Criteria to be a mangrove:
1. Complete fidelity to the mangrove environment.
2. Plays a major role in the structure of the community and has the ability to form pure stands.
3. Morphological specialization for adaptation to the habitat.
4. Physiological specialization for adaptation to their habitat.
5. Taxonomic isolation from terrestrial relatives.
(P. Tomlinson, 1986)
Mangroves Ecosystems that are located in the Tropical and Subtropical parts of the Globe.
Most of the flora in this ecosystem is capable of tolerating high salinity levels.
Have the capacity to resist low oxigen levelsin the soils.
Can survive in completly floaded conditions.
(Kathiresan and Bingham, 2001)IFGP 2014
Mangroves structureMangroves forests have the following attributes in terms of their structure: ◦ species richness
◦ canopy height
◦ basal area
◦ tree density
◦ age/size class distribution
◦ low understory development
( K. Mckee, 1996 )
Mangroves fallow the detrital type of food web in terms of trophic structure.
(Odum & McIvor 1990)
Mangrove distributionThe mangrove infauna consists of species that spend most or all of the adult life within the substrate, boring into hard substrates or burrowing in soft sediments
“The mangrove epifauna consists of animals that may move over, or are attached to, hard or soft substrates.”
(Levinton, 2001)
Infauna Sessile Epifauna
Mangroves distributionMangrove distribution is controlled by:
climate salinity tidal fluctuation sedimentation wave energy
Distribution of this ecosystems has been highly reduced due to human activities.
World Atlas of Mangroves by ITTO
Mangroves functions and services ECOLOGICAL FUNCTIONS
◦ Transitional zones
◦ Provide shelter
◦ Serve as nursery spots
◦ Sink many contaminants before reaching the ocean
◦ Highly productive areas
◦ Sites for accumulation of carbon, nutrients and sediments.
ANTHROPOGENIC SERVICES
◦ Provide wood*
◦ Protect inland areas from tides and major events such as hurricanes
◦ Host many species of fish
◦ Provide food and medicine resources*
* When used in a sustainable manner.
Mangroves as sinks“Sediments in the coastal zone are normally dominated by terrigenous particles due to the supply of continental material. With growing industrial activity, contaminants are released into the coastal environment causing undesirable effects on the marine ecosystem.”
(Natesan et al., 2014)
Mangroves serve as sinks for multiple contaminants including heavy metals. They cause a good effect by trapping them before they reach the marine environment but affect the delicate balance of the mangroves themselves and alter quality in which they can develop appropriately and healthy.
Mangroves as providersThey provide resources for species development:
“The infauna of mangrove associated Spartina marshes was investigated by Braga et al. (2009), who found that increasing macrofaunal diversity and abundance is associated with greater plant density”
(Beasley et al., 2010)
They provide habitat:
“The sediment surface, roots, living and dead plant material such as logs, branches and leaves are habitat for the epifauna”
(Beasley et al., 2010)
Mangroves challenges Humans ◦ Construction ◦ Deforestation ◦ Overfishing ◦ Padding
Climate Change ◦ Sea level rise ◦ Temperature rise ◦ Salinity rise
Natural disasters and phenomena ◦ Increase in intensity *◦ Decrease in frequency *
* As a result of climate change.
Human impact on mangroves Mangroves are very resilent organisms. Although they have been under constant preasure through the years.
Mangroves have to face humans and survive: ◦ Deforestation:
“...mangrove deforestation is occurring at a rate of 1–2 % per year...”
(Alongi, 2002)
◦ Construction:
Many mangrove ecosystems have been destroy for urban development.
◦ Padding:
Mangroves were pad in the past because they were consider a threat for human health, they were poorly valued, and necesary for the development of coastal urban sites.
IFGP 2014
Human Impact on Mangroves
“…20% decline in last 25 years due mainly to conversion and coastal development 3-4 times faster than terrestrial forest coastal development…”
(World Atlas of Mangroves by ITTO)
“Despite high rates of destruction, mangroves still play an important role in human sustainability and livelihoods in developing nations where poverty is rife and population growth is high”
( Alongi, 2015)
Climate Change The ICPP predicted several changes in terms of global climate change and among others they found that for 2081-2100 the measurements of salinity, precipitation and sea level will fallow the below patterns:
( Alongi, 2015 )
Mangroves and Climate ChangeResponse to rise in temperatures
“Temperature increases alone are likely to result in faster growth, reproduction, photosynthesis, and respiration, changes in community composition, diversity, and an expansion of latitudinal limits.”
( Tittensor, 2010)
“An experimental study has shown that juvenile mullet (Liza vaigiensis) and crescent terapon(Terapon jarbua) frequenting tropical seagrass beds can be acclimated to higher water temperatures, approaching the critical limits for marine vertebrates. Other organisms such as tropical gastropods may respond actively by seeking cooler sites to survive when temperatures exceed 33 °C.”
(Alongi, 2015)
Mangroves and Climate Change Responses to rising CO2 :
“Higher CO2 concentrations can enhance the growth of mangroves, but responses are species-specific...”
“The simulation analysis suggests that temperature changes will be a more important driver than increasing CO2 and that different mangrove species will differ in their sensitivity to increases in both drivers.”
( Alongi, 2015)
“Furthermore, feedbacks may exist between CO2 concentrations, root biomass, and elevation gain”
(Saintilan, 2014)
Mangroves and Climate ChangeResponse in rising sea level
“Over geological time, as sea level has waxed and waned in relation to alternating periods of glaciation and warming, mangroves have had to adjust (or not) to rises and falls in sea level.”
(Alongi, 2015)
The key issue with the current rate of sea rising is that mangroves will not have the time they need to migrated so safer zones or make the physiological and morphological adaptations to survive in the new conditions.
Nor they will have space to migrate because of urban development which varies from past periods of glaciation and warming.
Discussion Questions 1) Which attributes of mangroves can benefit both humans and the environment, and how can we manage them in good manner?
2) How can we establish the level of sustainability in which activities involving mangroves are done and what management approaches can be taken to assure the best possible practices in this ecosystem?
3) Which do you think is the best approach in the debate for mangrove protection ?
4) Having in consideration the lack of space for mangroves to migrate inland as consequence of sea level rise, what do you propose it should be done ?
5) What technical measurements can we propose for the reduction of sedimentation in the mangrove ecosystems and the other environment linked to this one?
6) How are mangroves important for the economy and how their best state and health favors Puerto Rican economy?
References Alongi, D. M. 2015. The Impact of Climate Change on Mangrove Forests. Curr. Climate Change Repository. Springer International Publishing.
Alongi, D. M. 2002. Present state and future of the world’s mangrove forests. Environ Conserv. 29:331–49
C.R. Beasley, M.E.B. Fernandes, E.A.G. Figueira, D.S. Sampaio, K.R. Melo, and R.S. Barros. 2010. Mangrove Dynamics and Management in North Brazil. Volume 211 of the series Ecological Studies. 109-123
Janzen, D. H. 1985. Mangroves: where’s the understory. Journal of Tropical Ecology 1: 89-92.
Kathiresan, K., and B. L. Bingham. 2001. Biology of mangroves and mangrove ecosystems. Advances in Marine Biology, Vol 40 40:81-251.
McKee, K. 1996. Mangrove Ecosystems: Definitions, Distribution, Zonation, Forest Structure, Trophic Structure, and Ecological Significance. Smithsonian Environmental Research Center, Smithsonian Institution.
Natesan, U., Kumar, M., Deepthi, K. 2014. Mangrove sediments a sink for heavy metals? An assessment of Muthupet mangroves of Tamil Nadu, southeast coast of India. Springer-Verlag Berlin Heidelberg.
Odum, W.E. and C.C. McIvor. 1990. Mangroves.. In Ecosystems of Florida, R. L. Myers and J. J. Ewel (eds.). University of Central Florida Press.517-548
Saintilan N., Rogers K. 2014. Woody plant encroachment of grasslands: a comparison of terrestrial and wetland settings. New Phytol.
Tittensor DP, Mora C, Jetz W, Lotze HK, Ricard D, Vanden Berghe E, et al. 2010. Global patterns and predictors of marine biodiversity across taxa. Nature, 466:1098–101.
Tomlinson, P. B. 1986. The botany of mangroves. Cambridge University Press, Cambridge, United Kingdom.
