Assessing the impacts of climate change on reproductive phenology in tropical rainforests of Southeast Asia

In humid forests in Southeast Asia, many species from dozens of plant families flower gregariously and fruit synchronously at irregular multi-year intervals 1–4 . Little is known about how climate change will impact these community-wide mass reproductive events. Here, we perform a comprehensive analysis of reproductive phenology and its environmental drivers based on a monthly reproductive phenology record from 210 species in 41 families in peninsular Malaysia. We find that the proportion of flowering and fruiting species decreased from 1976 to 2010. Using a phenology model with inputs obtained from general circulation models, we show that low-temperature flowering cues became less available during the monitoring period and will further decrease in the future, leading to decreased flowering opportunities in 57% of species in the Dipterocarpaceae family. Our results highlight the vulnerability of and variability in phenological responses across species in tropical ecosystems that differ from temperate and boreal biomes.