Phenology studies the seasonal cycle of plants and describes it through key events such as flowering and bud-burst (in spring) and leaf coloration and fall (in autumn). These events are crucial for the annual growth of the plants, with implication for ecosystem biomass production and biogeochemistry (for example, carbon and nitrogen cycling). Therefore phenology allows us to understand plant functioning, interactions between terrestrial ecosystem and atmosphere, and the services that ecosystems provide us. Phenology is also an excellent indictors of climatic changes. For instance, the earlier bud-burst of deciduous trees has been one of the first clear signs of the impact of climate warming on temperate forests.
Within PLECO, we primarily focus on phenology of temperate deciduous trees. Since 10 years we investigate the impact of temperature and light (daylength) on bud-burst of common trees such as beech, oak and birch. Since 2016, we started also extensive research on autumn phenology (see project LEAF-FALL), investigating the still unknown environmental triggers of leaf senescence, the process allowing the relocation of leaf nutrients to the wood before leaf shedding. At the same time, we started to study phenology also of wood and fine roots, that also start (and stop) to growth at precise periods in spring (and autumn). Finally, since 2019, we investigate the winter “dormancy” of trees, to understand (also at molecular level) what happen to buds and trees during their resting phase and how winter conditions might effect next spring. At PLECO, we studies plant phenology also in herbs, for example, to understand impact of climate changes on grasslands.
All these different aspects are investigated mainly through eco-physiological experiments manipulating the growth environment of trees (warmed greenhouses, rain shelter to induce drought etc.), and long-term observations on mature tress across European forests. Moreover, we have also projects on remote sensing detection of phenology (for example, regional greening in spring) and integrate our results in models, applied to individual tree, forest stand and up to the global level.