Tree phenology and abiotic variables 1998-2017 at Ngogo, Kibale National Park, Uganda

Fruit production in tropical forests varies considerably in space and
time, with important implications for frugivorous consumers.
Characterizing temporal variation in forest productivity is thus critical
for understanding adaptations of tropical forest frugivores, yet long-term
phenology data from the tropics, in particular from African forests, are
still scarce. Similarly, as the abiotic factors driving phenology in the
tropics are predicted to change with a warming climate, studies
documenting the relationship between climatic variables and fruit
production are increasingly important.  Here we present data from
19 years of monitoring the phenology of 20 tree species at Ngogo in Kibale
National Park, Uganda. Our aims were to characterize short- and long-term
trends in productivity and to understand the abiotic factors driving
temporal variability in fruit production. Short-term (month-to-month)
variability in fruiting was relatively low at Ngogo, and overall fruit
production increased significantly through the first half of the study.
Among the abiotic variables we expected to influence phenology patterns
(including rainfall, solar irradiance, and average temperature), only
average temperature was a significant predictor of monthly fruit
production. We discuss these findings as they relate to the resource base
of the frugivorous vertebrate community inhabiting Ngogo.