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Mangroves as organic records Miguel Ángel Mateo Mínguez - Centro de Estudios Avanzados de Blanes - CSIC Máster Universitario en Cambio Global Doctorado.

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Presentation on theme: "Mangroves as organic records Miguel Ángel Mateo Mínguez - Centro de Estudios Avanzados de Blanes - CSIC Máster Universitario en Cambio Global Doctorado."— Presentation transcript:

1 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

2 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

3 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

4 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

5 Mangroves Application examples Quantification of whole- ecosystem 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. Donato et al Miguel Ángel Mateo Mínguez - Centro de Estudios Avanzados de Blanes - CSIC

6 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. Twin Cays, Belize McKee et al Miguel Ángel Mateo Mínguez Centro de Estudios Avanzados de Blanes - CSIC

7 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 record of sea-level change currently known. Chronology of selected events that occurred over the time period recorded in mangrove peat cores Video: outube_gdata Miguel Ángel Mateo Mínguez Centro de Estudios Avanzados de Blanes - CSIC

8 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 Wooller et al Miguel Ángel Mateo Mínguez Centro de Estudios Avanzados de Blanes - CSIC

9 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 Depth (m) Wooller et al Miguel Ángel Mateo Mínguez Centro de Estudios Avanzados de Blanes - CSIC

10 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) Wooller et al Miguel Ángel Mateo Mínguez Centro de Estudios Avanzados de Blanes - CSIC

11 Mangroves Application examples a b c d a Leaf fragment area (mm²) b stable nitrogen-isotope c stable carbon-isotope d stable oxygen-isotope Composition of leaf fragments 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 Wooller et al Miguel Ángel Mateo Mínguez Centro de Estudios Avanzados de Blanes - CSIC

12 Mangroves as a paleo-record Literature and web sites 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: 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: Wooller et al (2007) A multiproxy peat record of Holocene mangrove palaeoecology from Twin Cays, Belize. The Holocene. 17, 8: 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: Video:http://www.youtube.com/watch?v=1o4nz0hbR8U&feature=youtube_gdatahttp://www.youtube.com/watch?v=1o4nz0hbR8U&feature=youtube_gdata Miguel Ángel Mateo Mínguez - Centro de Estudios Avanzados de Blanes - CSIC

13 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


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