COMBINING CITIZEN SCIENCE PHENOLOGICAL OBSERVATIONS WITH REMOTE SENSING DATA

摘要

Citizen science is efficient to collect data about plant phenology across large areas such as Canada and independently for each species. However, such time series are often discontinuous and observations are not evenly distributed. On the other hand, remote sensing provides a synoptic view on phenology but does not inform about inter-species differences in phenological response to climate variability.Existing interactions between the two types of data are so far essentially limited to the evaluation of remote sensing methods by citizen science data, which proved quite efficient. Here we first use such an approach to show that one remote sensing method green-up date relates to the leaf-out date of woody species but also to the whole plant community phenology at the regional level, including flowering phenology. Second we use a remote sensing time series to constrain the analysis of citizen data to overcome the main drawbacks that is the incompleteness of time series. We analyze the interspecies differences in phenology at the scale of so-called “pheno-regions” delineated using remote sensing green-up maps.