Data from: Solar irradiance as the proximate cue for flowering in a tropical moist forest

We compared flowering times predicted by six possible proximate cues involving seasonal changes in rainfall and irradiance and flowering times observed over 30 years of weekly censuses for 19 tree and liana species from Barro Colorado Island (BCI), Panama. Hypotheses concerning variation in the timing and intensity of rainfall failed to predict flowering times in any species. In contrast, 10 to 12 weeks of consistent high levels of irradiance predicted flowering times well for eight species, and six or seven weeks of rapidly increasing levels of irradiance predicted flowering times well for two species. None of the six possible proximate cues predicted flowering times adequately for the nine remaining species. We conclude that high and increasing levels of irradiance are the proximate cues for flowering in many BCI species. The seasonal movements of the Intertropical Convergence Zone cause strong seasonal changes in cloud cover, atmospheric transmissivity and irradiance reaching the BCI forest. Inter-annual variation in the timing of movements of the Intertropical Convergence Zone is the most likely cause of inter-annual variation in the timing of flowering in these species. Much work remains to be done as the physiological mechanisms linking flowering and irradiance are unknown and the proximate cues for flowering remain to be identified for many other BCI species.我们对比了基于六种潜在近因触发信号所预测的开花时间——这些信号涉及降雨与辐照度（irradiance）的季节性变化——以及基于30年每周野外普查所观测得到的19种巴拿马巴罗科罗拉多岛（Barro Colorado Island, BCI）树木与藤本植物的开花时间。针对降雨时间与强度变化的相关假说，无法准确预测任一物种的开花时间。与之相反，8个物种的开花时间可通过持续10至12周的高水平辐照度实现准确预测，另有2个物种的开花时间则可通过持续6至7周的快速升高辐照度水平得到准确预测。剩余的9个物种则无法通过上述六种潜在近因触发信号中的任何一种实现开花时间的充分预测。本研究据此得出结论：高水平且持续升高的辐照度，是巴罗科罗拉多岛诸多物种开花的近因触发信号。热带辐合带（Intertropical Convergence Zone）的季节性移动，会导致抵达巴罗科罗拉多岛森林的云量、大气透射率以及辐照度出现显著的季节性变化。热带辐合带移动时间的年际变化，极有可能是这些物种开花时间出现年际差异的核心诱因。目前仍有大量研究工作亟待开展：连接开花过程与辐照度的生理机制尚未明确，且巴罗科罗拉多岛诸多其他物种的开花近因触发信号仍有待探明。