Plant phenology and climate change

Phenology, the timing of annually recurrent reproductive biological events, provides a critical signal of climate variability and change effects on plants. Considerable work over the past five decades has quantified the extent to which plant phenophases are responding to local changes in temperature and rainfall. Originally undertaken through the analysis of ground-based phenological observations, the discipline has more recently included phenophase indicators from satellite images and digital repeat photography. With research advances it has become evident that the responses of plant phenology to climate variability and change are both location- and species-specific. The extent to which plants are affected by changes in temperature and rainfall, their intrinsic adaptation capacity, will ultimately determine the potential for sustained ecological stability and food security. We review methodological approaches to plant phenological-climate change over time, analyse the regions and phenophases for which climate variability demonstrates a clear causal role, and finally reflect on the applications of phenological climate change investigations in broader biogeographical contexts.