Ecosystem services of floodplain grasslands: Defining fodder production  in the Tana delta Crystèle Léauthaud 16 August 2011
Introduction <ul><li>Importance of floodplain grasslands </li></ul><ul><ul><li>Potential natural vegetation of grasslands ...
Study zone:  the Tana delta <ul><li>Importance of the Tana river </li></ul><ul><ul><li>Only permanent river in an extremel...
Methodology <ul><li>Couple a hydrological model of the Tana river and a grass production model </li></ul><ul><ul><li>Simpl...
Results and discussion:  hydrology <ul><li>The model of flood dynamics upstream of the delta has been constructed </li></u...
Grassland modeling Living root biomass Stem Leaves Dead aerial biomass Gross photosynthesis Growth respiration Growth resp...
Experimental plot: data acquisition for calibration and validation <ul><li>Simulation of floods </li></ul><ul><ul><li>Grow...
Analysis <ul><li>…  still ongoing! </li></ul><ul><li>NDVI  of grasslands higher than surroundings but need to investigate ...
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Ecosystem services of floodplain grasslands: Defining fodder production in the Tana delta

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Presented by Crystele Leauthaud, ILRI, Nairobi, 16 August 2011


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Ecosystem services of floodplain grasslands: Defining fodder production in the Tana delta

  1. 1. Ecosystem services of floodplain grasslands: Defining fodder production in the Tana delta Crystèle Léauthaud 16 August 2011
  2. 2. Introduction <ul><li>Importance of floodplain grasslands </li></ul><ul><ul><li>Potential natural vegetation of grasslands represent 25% of terrestrial surface (Shantz 1954 in Daily & Matson 2008) </li></ul></ul><ul><ul><li>Vulnerable ecosystems: development projects, climate change (Johnson et al. 2010) etc. </li></ul></ul><ul><ul><li>Degraded (Leyer 2005; MEA 2005) : </li></ul></ul><ul><ul><ul><li><1990 : - 53% of flooded grasslands and savannas </li></ul></ul></ul><ul><ul><ul><li><2050 : - 11% (MEA, 2005) </li></ul></ul></ul><ul><ul><li>Many ecosystem services: </li></ul></ul><ul><ul><ul><li>Fodder production, fish production, flood attenuation, ground-water recharge, improvement water quality etc. </li></ul></ul></ul>Objective: quantify the ecosystem service of fodder production of tropical floodplain grasslands This ES is defined by the quality of the fodder but also its quality and seasonnality 
  3. 3. Study zone: the Tana delta <ul><li>Importance of the Tana river </li></ul><ul><ul><li>Only permanent river in an extremely dry region </li></ul></ul><ul><ul><li>Vital water resource for local communities </li></ul></ul><ul><li>Qualifies as a RAMSAR site/biodiversity hotspot </li></ul><ul><ul><li>Many threatened and vulnerable animal and plant species, including endemic primates (Tana river Colobus and Mangabey) </li></ul></ul><ul><li>Important for the livestock keepers of the whole region </li></ul><ul><ul><li>>75 000 TLU were grazing in the Tana delta grasslands (June 2010, DRSRS) </li></ul></ul><ul><ul><li>> 2.5million livestock depend on the Tana’s grasslands for dry-season pasture and water (CADP 1991 in Emerton 2003) </li></ul></ul><ul><li>Many threats: </li></ul><ul><ul><li>biofuels and large-scale agricultural projects: important to quantify the current value of the ecosystems </li></ul></ul><ul><ul><li>Past and future hydro-electrical dams have and will again modify the flow regime of the Tana river, on which rely the ecosystems and the local communities </li></ul></ul>TLU density Floodplain grasslands
  4. 4. Methodology <ul><li>Couple a hydrological model of the Tana river and a grass production model </li></ul><ul><ul><li>Simple conceptual models </li></ul></ul><ul><li>Calibrate and validate the models with field and RS data at different scales </li></ul><ul><li>Simulate the productivity of the grasslands in the past ten years </li></ul>Scale Model Calibration Validation Data Experimental plot Plant ✔ ✔ Field Transect Plant ✔ Field Grassland Plant ✔ RS Delta Hydrological ✔ ✔ RS
  5. 5. Results and discussion: hydrology <ul><li>The model of flood dynamics upstream of the delta has been constructed </li></ul><ul><li>The flood dynamics within the delta still needs to be modelled </li></ul><ul><ul><li>Using MODIS 500m, 8 days synthesis products (MOD09A1) </li></ul></ul>97-98 El Nino 2002 2006 2009 drought
  6. 6. Grassland modeling Living root biomass Stem Leaves Dead aerial biomass Gross photosynthesis Growth respiration Growth respiration Growth respiration Translocation Maintenance respiration Maintenance respiration Grazing Senescence Senescence Senescence Maintenance respiration Soil and water model
  7. 7. Experimental plot: data acquisition for calibration and validation <ul><li>Simulation of floods </li></ul><ul><ul><li>Growth model must be able to simulate grass growth during floods, even though most biomass is not consumed (animals out of delta) </li></ul></ul><ul><ul><li>Here simulating a 4 month flood </li></ul></ul><ul><li>Simulation of non flooded conditions </li></ul><ul><ul><li>Different rain (red blocks, 0/4/8mm irrigated water/per day) and grazing scenarios (blue sub-blocks, cuttings every 2/4/8weeks) </li></ul></ul><ul><ul><li>Post-flood most important period to simulate as the animals return to the Tana to graze </li></ul></ul>irrigation Daily r ain, temperature measurements controls
  8. 8. Analysis <ul><li>… still ongoing! </li></ul><ul><li>NDVI of grasslands higher than surroundings but need to investigate further (SPOT vegetation) </li></ul><ul><li>Experimental plot: </li></ul><ul><ul><li>Shows significant effect of irrigation on grass productivity </li></ul></ul><ul><ul><li>Ends December 2011 </li></ul></ul>
  9. 9. Thank-you

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