1. Global Vegetation Monitoring Unit, Joint Research Centre, TP 440, 21020 Ispra, Italy.
2. Land Use–Land Cover Unit, Joint Research Centre, TP 263, 21020 Ispra, Italy.
3. Conservation Technology Limited, 4 Old Tarnwell, Somerset BS18 4EA, UK.
4. Science Strategy Directorate, Joint Research Centre, European Commission, B-1049 Bruxelles, Belgium.