New paper on tree phenology and microclimate in Agricultural and Forest Meteorology
Cedric Zahnd, Günter Hoch and co-authors published a new study on how vertical microclimatic canopy gradients cause phenological variations within mature tree crowns.
Tree crowns are exposed to strong vertical gradients in light, temperature and humidity. In this study, Cedric Zahnd, Günter Hoch and co-authors explored how these gradients influence the leaf phenology within mature, temperate tree crowns. At the Swiss Canopy Crane II site near Basel, Switzerland, they measured microclimate and phenology in the upper and lower crown areas of nine species over three years. During summer and autumn, conditions in the upper crown were sunnier, hotter and drier than in the lower crown areas, but these differences were negligible outside the growing season. Accordingly, leaf flushing in spring occurred synchronously within the crowns, while the hotter and drier summer conditions led to earlier autumn senescence of upper leaves in many species. The results highlight small-scale phenological variations as a potential mechanism for optimising carbon uptake within tree crowns.
Link to the paper: