Mangroves as organic records
Miguel Ángel Mateo Mínguez - Centro de Estudios Avanzados de Blanes - CSIC
Máster Universitario en Cambio Global
Doctorado
Programa Oficial de Posgrado adaptado al EEES
Mangroves
Distribution of the record
Mangroves:
The word 'Mangroves'' refers to a
diverse group of unrelated plants
that share a common ability to live
in waterlogged saline soils
subjected to regular flooding. They
are highly specialised and adapted
plants in order to survive in
unstable conditions.
Global Mangrove distribution:
Mangroves are distributed
circumtropically, and are largely
restricted to latitudes between 30°
N and 30° S. Total mangrove
coverage is 18 million hectares,
which represents only 0.45% of
world forests & woodland.
Miguel Ángel Mateo Mínguez - Centro de Estudios Avanzados de Blanes - CSIC
Mangroves
Mangrove types
Of the 80 different species most common are:
Red Mangrove:
It usually grows near the shore of the water,
has red roots that raise over the water.
Black Mangrove:
It grows in higher areas than the red
mangrove and its roots spread near the trunk
in shapes of fingers.
White Mangrove:
It grows in higher areas than the black
mangrove and the roots are not visible.
Miguel Ángel Mateo Mínguez - Centro de Estudios Avanzados de Blanes - CSIC
Mangroves
Structure, formation, dynamics
Mangrove soils develop through a
combination of mineral sediment
deposition and organic matter
accumulation.
The mangrove peat is composed
primarily of refractory roots.
Because mangrove soils are
waterlogged and nutrient
availability is low, decomposition
of mangrove roots and other
plant tissues is extremely slow
(only a few mm per year).
Miguel Ángel Mateo Mínguez
Centro de Estudios Avanzados de Blanes - CSIC
Donato et al. 2011
Mangroves
Application examples
Quantification of wholeecosystem carbon storage:
Measured:
- tree and dead wood biomass
-soil carbon content
- soil depth
in 25 mangrove forests in the
Indo-Pacific region
Mangroves are among the most
carbon-rich forests in the
tropics, containing on average
1,023 Mg carbon/ha.
Organic-rich soils accounted for
49–98% of carbon storage in
these systems.
Mangrove deforestation
generates about 10 % of
emissions from deforestation
globally.
Miguel Ángel Mateo Mínguez - Centro de Estudios Avanzados de Blanes - CSIC
Twin Cays, Belize
Mangroves
Application examples
Mangroves and Sea-Level
Change in Belize
The mangrove islands in Belize
contain deep deposits of peat
(organic matter formed from
plants) as much as 11 m.
These peat deposits have
accumulated over thousands of
years as the climate has warmed
and sea level has risen. The peat
is composed of the decaying parts
of mangroves, that are preserved
in the flooded and anoxic soil.
Miguel Ángel Mateo Mínguez
Centro de Estudios Avanzados de Blanes - CSIC
McKee et al. 2007
Mangroves
Application examples
Mangroves and Sea-Level Change
in Belize
The collected peat sections are
radiocarbon-dated to determine
their age. The peat record at Twin
Cays spans almost the entire
Holocene Epoch (10,000 years) and
the rise of human civilization.
Botanical and chemical analyses
show which plants were present
and what the environmental
conditions were like at various
times.
This is longest continuous peat
Chronology of selected events that occurred over the
record of sea-level change currently time period recorded in mangrove peat cores
known.
Video:
Miguel Ángel Mateo Mínguez
Centro de Estudios Avanzados de Blanes - CSIC
http://www.youtube.com/watch?v=1o4nz0hbR8U&feature=y
outube_gdata
Mangroves
Application examples
Multiple proxies of past
mangrove ecosystems
-780 cm long peat core
recorded palaeoecological
changes since ~8000 years
Proxies included:
- Pollen
- stable-isotope (C, N and O)
compositions of mangrove
leaf fragments
- Accumulation rate and
relative peat hardness
Mangrove peat core
Light microscope images of Rhizophora (red mangrove)
pollen
Miguel Ángel Mateo Mínguez
Centro de Estudios Avanzados de Blanes - CSIC
Wooller et al. 2007
Miguel Ángel Mateo Mínguez
Centro de Estudios Avanzados de Blanes - CSIC
Mangroves
Application examples
Pollen diagram:
- Shows the vegetation groups and pollen concentrations at different depths of the core
- Rhizophora mangle (red mangrove) has been dominant at this site for over ~8000 years
- The presence of mangrove pollen in the sediments indicates a warm climate and a nearby
shoreline at the time the pollen were deposited
Mangroves
Other trees and herbs
Wooller et al. 2007
Mangroves
Application examples
Peat accumulation rates:
A decline in peat
accumulation rate at ~7200
cal. yr BP correlates with a
decrease in the rate of rise in
sea level.
Hardness of peat:
Provides physical
characteristics of a peat and
and is a potential correlation
tool with other proxies.
a) Peat-accumulation rates between radiocarbon dates
b) Relative hardness and softness of peat (Penetrometer)
Miguel Ángel Mateo Mínguez
Centro de Estudios Avanzados de Blanes - CSIC
Wooller et al. 2007
a
b
c
d
Mangroves
Application examples
Stable-isotope (C, N and O) :
Stable carbon and nitrogen
isotope analyses are useful
to track past changes in
mangrove floral
composition, stand structure
and nutrient limitations.
Stable-oxygen-isotope
composition recorded
variations in the proportion
of seawater versus
precipitation taken up by
past mangroves  due to
changes in sea-level rise
Miguel Ángel Mateo Mínguez
Centro de Estudios Avanzados de Blanes - CSIC
a Leaf fragment area (mm²)
b stable nitrogen-isotope
c stable carbon-isotope
d stable oxygen-isotope
Composition of
leaf fragments
Wooller et al. 2007
Mangroves as a paleo-record
Literature and web sites
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Buillon (2011) Carbon cycle: Storage beneath mangroves. Nature Geoscience. 4: 282–283.
Donato et al (2011) Mangroves among the most carbon-rich forests in the tropics. Nature
Geoscience. 4: 293–297.
Ellison (2008) Long-term retrospection on mangrove development using sediment cores and
pollen analysis: A review. Aquatic Botany. 89, 2: 93-104.
McKee et al (2007) Caribbean mangroves adjust to rising sea level through biotic controls on
change in soil elevation. Global Ecology and Biogeography. 16, 5: 545-556.
Wooller et al (2007) A multiproxy peat record of Holocene mangrove palaeoecology from
Twin Cays, Belize. The Holocene. 17, 8: 1129-1139
Wooller et al (2009) Late Holocene hydrologic and vegetation changes at Turneffe Atoll, Belize,
compared with records from mainland Central America and Mexico. Palaios. 24, 10: 650-656.
http://www.nt.gov.au/nreta/wildlife/nature/pdf/mangroves/2_mangrove_ecosystem.pdf
http://www.nwrc.usgs.gov/factshts/2004-3126/2004-3126.htm
Video:http://www.youtube.com/watch?v=1o4nz0hbR8U&feature=youtube_gdata
Miguel Ángel Mateo Mínguez - Centro de Estudios Avanzados de Blanes - CSIC
Acknowledgements:
Special thanks are due to Kathrin Bacher for her strong
contribution in the elaboration of this presentation.
Miguel Ángel Mateo Mínguez - Centro de Estudios Avanzados de Blanes - CSIC