University of Minnesota, Department of Forest Resources, St. Paul, MN USA.
University of Florida Extension Education, Fort Lauderdale, FL, USA.
Ann Bot. 2021 Jan 7;127(2):203-211. doi: 10.1093/aob/mcaa156.
Warmer temperatures and altered precipitation patterns are expected to continue to occur as the climate changes. How these changes will impact the flowering phenology of herbaceous perennials in northern forests is poorly understood but could have consequences for forest functioning and species interactions. Here, we examine the flowering phenology responses of five herbaceous perennials to experimental warming and reduced summer rainfall over 3 years.
This study is part of the B4WarmED experiment located at two sites in northern Minnesota, USA. Three levels of warming (ambient, +1.6 °C and +3.1 °C) were crossed with two rainfall manipulations (ambient and 27 % reduced growing season rainfall).
We observed species-specific responses to the experimental treatments. Warming alone advanced flowering for four species. Most notably, the two autumn blooming species showed the strongest advance of flowering to warming. Reduced rainfall alone advanced flowering for one autumn blooming species and delayed flowering for the other, with no significant impact on the three early blooming species. Only one species, Solidago spp., showed an interactive response to warming and rainfall manipulation by advancing in +1.6 °C warming (regardless of rainfall manipulation) but not advancing in the warmest, driest treatment. Species-specific responses led to changes in temporal overlap between species. Most notably, the two autumn blooming species diverged significantly in their flowering timing. In ambient conditions, these two species flowered within the same week. In the warmest, driest treatment, flowering occurred over a month apart.
Herbaceous species may differ in how they respond to future climate conditions. Changes to phenology may lead to fewer resources for insects or a mismatch between plants and pollinators.
随着气候变化，预计气温将继续升高，降水模式也将发生变化。这些变化将如何影响北方森林草本多年生植物的开花物候，目前了解甚少，但可能会对森林功能和物种相互作用产生影响。在这里，我们研究了 5 种草本多年生植物对 3 年实验增温和夏季减少降雨的开花物候响应。
本研究是位于美国明尼苏达州北部两个地点的 B4WarmED 实验的一部分。三个增温水平（环境温度、+1.6°C 和+3.1°C）与两个降雨处理（环境和 27%的生长季降雨减少）交叉。
我们观察到物种对实验处理的特异性反应。单独增温使 4 个物种的开花提前。最值得注意的是，两种秋季开花的物种对增温表现出最强的开花提前。单独减少降雨使一种秋季开花的物种提前开花，而另一种则延迟开花，对三种早期开花的物种没有显著影响。只有一种植物，Solidago spp.，对增温和降雨处理的交互作用有反应，在+1.6°C 的增温中提前开花（无论降雨处理如何），但在最温暖、最干燥的处理中没有提前开花。物种特异性的反应导致物种之间的时间重叠发生变化。最值得注意的是，两种秋季开花的物种在开花时间上有显著的差异。在环境条件下，这两个物种在同一周内开花。在最温暖、最干燥的处理中，开花时间相隔一个月。
草本物种对未来气候条件的反应可能不同。物候变化可能导致昆虫资源减少或植物与传粉者之间不匹配。
