Abstract :
[en] Using various data sources, we addressed the diversity of phenological strategies and trends witnessed across Africa, and the consequences for forest management. Using field observations in several sites (n=11) across Central Africa, the size at reproduction, a key aspect of species life history, was evaluated for most major timber species (n=31 species). Diameter at reproduction strongly varied among species and was correlated with adult stature (maximum diameter and height). For some species, reproductive diameter thresholds showed substantial variation between sites, and crown exposure to light had a significant positive effect on reproductive status. The majority of minimum cutting diameter limits (MCDLs, imposed by national forest administration) was found to be suitable, trees having high probability for being seed trees at MCDL. Using field and herbarium data, the spatial variation in flowering phenology was examined across the whole range of species, and using remotely-sensed data of vegetation activity (EVI from MODIS satellite), the reversed phenology on both side of the climatic hinge, the area in Atlantic Central Africa where the rainfall seasonality reverses, was specifically examined. Herbarium data can be used to derive phenological information, and specifically the onset of flowering, probably because most central African tree species have a regular and annual phenology. She also found strong support for the spatial variation in tree phenology associated with the shift in rainfall seasonality, for flowering (field and herbarium data) and for forest functioning (EVI seasonality), with however, differences among species.
