Global Trend Analysis for Phenology & Vegetation Productivity
SIGMA or Stimulating Innovation for Global Monitoring of Agriculture, is an international research project that aims to improve the large scale earth observation based monitoring of agriculture. In one of its research topics, carried by VITO Remote Sensing and project partner Geoville, long-term changes in plants phenology are analyzed on a global scale.
Vegetation phenology shows us impact on global agriculture
Vegetation phenology is an increasing interest of the scientific community. Interannual changes in phenological parameters like the start- end and length of season are indicators for natural (e.g. climatological) or unnatural (e.g. land degradation) drivers. Time series of earth observation based indices, like the well known NDVI, give a good idea of the vegetation behaviour in the course of the year. In this study, we applied a module from the SPIRITS software (developed by VITO Remote Sensing for EC – Joint Research Centre) to estimate the start- end and length of the growing season at a global scale for the last 30 years. Gradual changes of these seasonality parameters were further investigated by means of trend analyses. The resulting global maps indicate where on Earth the plant phenology is shifting and can be linked with underlying factors such as climate change, rainfall distribution, forest degradation etc. In this study, relations with trends in rainfall and soil moisture were examined and the results were interpreted locally with partners from Argentina, China and the African Sahel.
Climate changes effects growing seasons all over the world
Global trend analyses show the gradual change of the length of season over the last 30 years. A diverse picture with patterns of increasing (elongation of the growing season, in green) and decreasing (shortening of the growing season, in red) trends across the globe is revealed. The results for example confirm that the growing season are becoming longer and longer in the boreal regions. Also the greening of Sahelian band due to increasing rainfall in the last decades is clearly visible. Non-natural influences are shown in Argentina, where many forested areas where cleared for agricultural purpose, which have typically a shorter growing season.
Results help us explain changes in agricultural productivity
Such results, which should be interpreted with ancillary information on natural and unnatural changes, can help to explain changes in agricultural productivity and be used to support crop monitoring activities.
SIGMA is coordinated by VITO Remote Sensing. With 22 partners we contribute to the global monitoring initiative GEOGLAM (Group on Earth Observation Global Agricultural Monitoring).
VITO Remote Sensing