Forest Monitoring: Chapter 9. Tree PhenologyThe chapter describes methodologies for harmonized phenological assessments based on a limited set of development phases: flushing, flowering, secondary flushing, color change, and leaf/needle fall. Manual phenological observations are based on a brief examination in the forest stands. More recently, the use of terrestrial digital image photography for forest phenology monitoring has been adopted. Vegetation indices, such as the normalized difference vegetation index (NDVI) have been used for many years to quantify the phenology of different ecosystems. For satellite-based remote sensing of vegetation phenology, phenological metrics are derived from time series of optical data and represent the only possible assessment of phenology over large and inaccessible regions. All indirect methods using optical vegetation indices from digital camera or NDVI sensors need to be validated against ground observations, for which manual tree phenological observations from the forest monitoring plots are often used. Examples from phenological monitoring in Slovenia, France, United Kingdom, and Finland are presented. |
Common terms and phrases
Agr Forest Meteorol AgroParisTech approach which potentially associated with field-based Autumn coloring autumn leaf coloring budburst canopy structure climate change Conifers d'Etude des Ressources Davi H deciduous forest difference vegetation index different ecosystems digital camera systems digital image photography ecosystems Elsevier European beech evergreen forests Fagus sylvatica FIGURE Finland flowering forest ecosystems forest monitoring plots forest stands France green-up ground observations Ground-based NDVI growing season length ICP Forests individual tree level intensive forest monitoring intensive monitoring plots Intergovernmental Panel key phenological events Larix decidua Leaf fall leaf unfolding Ljubljana main phenological events Manual Phenological Observations models NDVI time series needle appearance normalized difference vegetation Norway spruce optical vegetation indices Panel on Climate phenological phase phenology of different Picea abies plot level predicted Punkaharju quantify the phenology Random Forests Scots pine secondary flushing Slovenia Slovenian Forestry Institute Terrestrial Digital Image tree species United Kingdom University of Paris vegetation phenology