Ecological Impacts of the Tsunami: Field observations from Sri Lanka

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1 Ecological Impacts of the Tsunami: Field observations from Sri Lanka Dr. Jane Carter Ingram, Dr. Cristina Rumbaitis del Rio, Dr. Guillermo Franco, Dr. Bijan Khazai

2 Affected zones and sites assessed by Earth Institute team in Sri Lanka

3 Post tsunami tsunami ecological questions What were the impacts of the tsunami on ecosystems and natural resources? What factors contribute to ecological resistance and resilience to a disturbance like the tsunami? What was the role of ecosystems in providing protection for human communities? How can these lessons be incorporated into reconstruction and future coastal zone planning?

4 Coastal ecosystems of Sri Lanka Terrestrial Human impacted landscapes Palm plantations Home gardens Dune systems Agricultural areas Protected areas Scrub forest Herbs and Grasses Dune systems Coastal/Marine (protected and unprotected) Coral reefs Seagrass Lagoons/estuaries Mangroves

5 Major ecological impacts of the tsunami Sand migration Sedimentation Beach erosion Loss of topsoil Invasive species outbreaks Prickly pear (Opuntia sp.) and mesquite (Prosopis juliflora) Uprooting, breaking and dying of coastal vegetation Soil salinisation Affects coastal vegetation and agricultural plots Debris Salinity intrusion into freshwater sources

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9 Ecological resistance to tsunami Sand dunes Seagrass Resistant tree species Coconut (Cocus Nucifera)* Eucalyptus sp. Neem (Azaradichta indica)* Tulip (Thespia populnea)*

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17 Ecological vulnerability to the tsunami Mangroves (in isolated clumps or on the front rows of dense patch)* Herbs and grasses* Shrub layers* Runners and creepers* Palmyrah *Evidence of resilience in the form of regeneration or recovery

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21 Landscape scale factors that contribute to damage Location of bay Elevation Coastal bathymetry Presence of lagoons/inland waterways

22 Ecological factors that contributed to resistance and resilience in tsunami zone Resistance Vegetation: : stem diameter (thick/tall or thin/very tall), height, elasticity, type of root system, salinity tolerance, type of leaves (drag) Tree resistance =f (stem diameter, height, elastic properties, salt tolerance, tap root depth, lateral root extent, leaf area index) Coral reefs: : Intactness, structure (branching Acropora sp., was damaged), degree of bleaching, depth Dunes: Intactness, height, degree of vegetation cover, location in relation to apex of bay Resilience Vegetation: : growth rate, salinity tolerance, degree of mechanical damage/ability to regenerate after breakage

23 Does ecological resistance/resilience influence social resistance/resilience? Sand dunes: : physical buffer Coral reefs: : physical buffer, support fish populations, influence sand budget on beaches Seagrass: : feeding grounds for fish, protect against shoreline erosion Mangroves : large stands act as physical buffers, serve as important nursery areas for fish populations; however, Sri Lanka has few dense stands of mangroves Resistant terrestrial tree species do not provide physical protection but have been crucial in post tsunami tsunami phases for food, drink, fibers, timber

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25 Post tsunami tsunami ecological impacts Increased fishing pressure in estuaries Increased demand for building materials in reconstruction process lime, sand, wood Resettlement sites have been located in ecologically sensitive areas and/or near protected areas Dumping of debris in lagoons

26 Incorporating ecological lessons learned into rebuilding process Utilize ecological portfolios of resistance and resilience for replanting in the coastal zone Protect important wave buffering ecosystems Utilize ecologically sustainable rebuilding materials Address tsunami threat on contextual basis, using site based factors that contribute to vulnerability