Fenologie

Fenologie, known in English as phenology, is the science of the timing of recurring biological events in plants and animals and how these timings are influenced by seasonal and climatic factors. Commonly tracked events include budburst and leaf unfolding, flowering and fruiting, insect emergence, bird migration, and breeding or hibernation. Phenology provides important indicators of seasonal climate and ecosystem health and is sensitive to temperature, photoperiod, precipitation, and extreme weather.

The field has a long historical lineage, with systematic observations expanding in the 18th–19th centuries. Modern phenology combines long-term field records with remote sensing, weather data, and citizen science. Data are collected through in situ observations, phenological cameras, and satellite-derived indices such as NDVI. Metrics include first leaf, first flower, peak flowering, green-up, and migration timing, often linked to accumulated heat units, or growing degree days.

Applications include agriculture and horticulture for crop development and pest forecasting, forestry for timber planning, and biodiversity research to study phenological mismatches between interacting species. Climate change has accelerated shifts in phenological timing, sometimes altering synchrony between species and affecting ecosystem services and agricultural yields.

Challenges include natural variability, regional differences, and biases in volunteer-based data, along with gaps in legacy records. Ongoing efforts aim to standardize protocols, expand networks, and integrate phenology with climate and ecological models to improve forecasting and policy-relevant assessments.