Remote sensing of phenological changes

Project aim: The project is focused on the calibration of remote sensing data, collected to identify phenological changes in woody plants, including the beginning, course, and end of phenophases with special reference to poplars as a source of allergenic pollen.

 

About the project: Long-term monitoring of phenology is the basis for an understanding of the external factors’ influence on the life cycle of plants. The spectral responses data set of selected plant species provides the basis for the selection of an appropriate approach for remote sensing detection and continuous monitoring of phenological changes. Simultaneous monitoring using different methods enables in situ measurements to serve as indicators of the course and changes in phenophases. Although the research was focused on trees, the established connections between the results of in situ measurement and remote sensing apply to herbaceous plants as well, since they are the result of physiological processes present in the life cycle of every plant species.

 

The focus of fieldwork is broadband and hyperspectral vegetation indices, with special attention to the analysis of differences in the spectral response between the lower, middle, and upper parts of the canopy in relation to flowering, leafing, and fruiting phenophases as well as their correlation with satellite imaging results.

 

The application of remote detection in the monitoring of phenological changes provides efficient and accurate information, which is detrimental for detecting the effects of climate change but also for planning activities related to individual phenophases (moving hives to pasture, pesticides application, managing allergic symptoms by avoiding allergens and starting therapy, etc.). Therefore, it is especially evaluated how the analyzed indices correlate with the course of the flowering season, which is described directly, by phenological observation, and indirectly, by the time series of atmospheric pollen concentrations.

 

An accurate system for detecting and monitoring phenological changes enables the improvement of the quality of phenological models’ forecasts which are the basis for planning the activities of foresters, farmers, and people allergic to pollen.