Dispersers and environment drive global variation in fruit color syndromes

The colors of fleshy fruits play a critical role in plant dispersal by
advertising ripe fruits to consumers. Fruit colors have long been
classified into syndromes attributed to selection by animal dispersers,
despite weak evidence for this hypothesis. Here, we test the relative
importance of biotic (bird and mammal frugivory) and abiotic (wet season
temperatures, growing season length, and UV-B radiation) factors in
determining fruit color syndrome in 3,163 species of fleshy-fruited
plants. We find that both dispersers and environment are important, and
they interact. In warm areas, contrastive, bird-associated fruit colors
increase with relative bird frugivore prevalence, whereas in cold places
these colors dominate even where mammalian dispersers are prevalent. We
present near-global maps of predicted fruit color syndrome based on our
species-level model and our newly developed characterizations of relative
importance of bird and mammal frugivores.

肉质果实的颜色通过向取食者宣传成熟果实的存在，在植物传播过程中发挥关键作用。长期以来，果实颜色被归为一类由动物传播者选择塑造的果实色彩综合征（fruit color syndrome），尽管支持这一假说的证据较为薄弱。本研究针对3163种肉质果实植物，检验了生物因子（鸟类与哺乳动物食果作用）和非生物因子（湿季温度、生长季长度以及UV-B辐射）在决定果实色彩综合征方面的相对重要性。研究发现，传播者与环境因子均发挥重要作用，且二者存在交互效应。在温暖区域，与鸟类相关的对比鲜明的果实颜色会随鸟类食果动物占比的提升而增多；而在寒冷区域，这类果实颜色即使在哺乳动物传播者占比较高的情况下仍占据主导地位。本研究基于物种级模型，以及我们新构建的鸟类与哺乳动物食果动物相对重要性特征，绘制了近全球尺度的果实色彩综合征预测地图。