Young Alyssa L, Bloodworth Kathryn J, Frost Morgan D T, Green Curtis E, Koerner Sally E
Department of Biology, University of North Carolina Greensboro, Greensboro, NC USA.
Plant Ecol. 2022;223(3):339-351. doi: 10.1007/s11258-021-01212-7. Epub 2021 Nov 26.
The longleaf pine (LLP) savanna ecosystem once covered ~ 92 million acres of the Southeast USA, but due to anthropogenic activities such as logging and fire suppression, only 3% of its once widespread historic range remains. While many restoration efforts are underway to conserve this biodiverse ecosystem, restoration must be done in the context of climate change. In the last few decades, heatwaves have increased in frequency and intensity across the Southeastern USA with further increases predicted. To expand our understanding of LLP savanna restoration in light of these changes, we ran a series of three simulated heatwave greenhouse experiments through a Course-based Undergraduate Research Experience (CURE) incorporating ~ 150 undergraduate researchers per experiment. We measured plant growth metrics for four understory grasses commonly used in LLP savanna restoration efforts. We found that while most grass plug individuals survived heatwave conditions, aboveground production was reduced due to heatwaves. This productivity decrease could result in less biomass available for the essential vegetation fire feedback loop, where fire increases grass biomass, and in turn, more grass provides more fuel for fire. These results imply that land managers can proactively compensate for biomass loss due to heatwaves by planting more grass plugs during initial restoration.
The online version contains supplementary material available at 10.1007/s11258-021-01212-7.
长叶松稀树草原生态系统曾经覆盖了美国东南部约9200万英亩的土地，但由于伐木和灭火等人为活动，其曾经广泛分布的历史范围如今仅剩下3%。尽管目前正在进行许多恢复工作以保护这个生物多样的生态系统，但恢复工作必须在气候变化的背景下进行。在过去几十年里，美国东南部的热浪在频率和强度上都有所增加，预计还会进一步加剧。为了根据这些变化扩展我们对长叶松稀树草原恢复的理解，我们通过一个基于课程的本科研究经验（CURE）开展了一系列三个模拟热浪温室实验，每个实验纳入了约150名本科研究人员。我们测量了长叶松稀树草原恢复工作中常用的四种林下草本植物的生长指标。我们发现，虽然大多数草块个体在热浪条件下存活了下来，但地上部分的产量因热浪而减少。这种生产力下降可能导致基本植被火反馈循环中可用的生物量减少，在这个循环中，火会增加草的生物量，反过来，更多的草又会为火提供更多燃料。这些结果表明，土地管理者可以在初始恢复阶段通过种植更多草块来主动补偿因热浪造成的生物量损失。
在线版本包含可在10.1007/s11258-021-01212-7获取的补充材料。
