Understory plant communities show resistance to drought, hurricanes, and experimental warming in a wet tropical forest
Understory plant communities show resistance to drought, hurricanes, and experimental warming in a wet tropical forest
复制标题
DOI：
10.3389/ffgc.2022.733967
复制
发表时间：
2022-07
期刊：
影响因子：
--
通讯作者：
A. M. Alonso-Rodríguez;T. Wood;Jamarys Torres‐Díaz;M. Cavaleri;S. Reed;B. Bachelot
中科院分区：
文献类型：
--
作者：
A. M. Alonso-Rodríguez;T. Wood;Jamarys Torres‐Díaz;M. Cavaleri;S. Reed;B. Bachelot
全球气候变化导致气温上升以及风暴和干旱等气候事件更加频繁和强烈。气候变化和干扰机制可能对植物群落产生非累加性影响，并导致我们尚未了解的复杂遗产。对于热带森林来说尤其如此，热带森林在调节全球气候方面发挥着重要作用。我们使用波多黎各热带气候变化响应实验 (TRACE) 的林下植被数据来评估植物群落如何应对气候变暖和干扰。 TRACE 林下植被经历了严重干旱（2015 年）、两年的实验性变暖（2016-2017 年和 2018-2019 年，一半地块温度高于环境温度 4°C），以及两次重大飓风（艾尔玛和玛丽亚，2017 年 9 月）。 2015年至2019年，每年对木本幼苗和幼树进行普查，并于2015年干旱结束后进行额外普查。我们评估了个体发育过程中干扰驱动的物种丰富度、多样性和组成的变化。然后，我们使用贝叶斯预测性状模型来评估物种如何应对干扰以及这如何影响植物群落的功能结构。我们的结果表明，飓风干扰后幼苗丰富度下降，而变暖后幼苗丰富度和多样性增加。我们发现幼苗和幼树的物种组成随时间发生变化，但每次干扰的个体影响并不显着。在这两个个体发育阶段，我们观察到对实验变暖做出反应的物种数量大约是对干旱和飓风做出反应的物种数量的两倍。功能结构的预测变化表明干扰驱动的功能向快速生长和耐旱物种的混合转变。我们的研究结果表明，热带森林林下群落对气候压力的抵抗力比预期更强，特别是在幼苗阶段。然而，物种组成变化的早期迹象表明，在气候变暖、干旱和飓风频繁发生的情况下，植物群落可能会随着时间的推移转向快速生长或耐旱的物种。
Global climate change has led to rising temperatures and to more frequent and intense climatic events, such as storms and droughts. Changes in climate and disturbance regimes can have non-additive effects on plant communities and result in complicated legacies we have yet to understand. This is especially true for tropical forests, which play a significant role in regulating global climate. We used understory vegetation data from the Tropical Responses to Altered Climate Experiment (TRACE) in Puerto Rico to evaluate how plant communities responded to climate warming and disturbance. The TRACE understory vegetation was exposed to a severe drought (2015), 2 years of experimental warming (4°C above ambient in half of the plots, 2016–2017 and 2018–2019), and two major hurricanes (Irma and María, September 2017). Woody seedlings and saplings were censused yearly from 2015 to 2019, with an additional census in 2015 after the drought ended. We evaluated disturbance-driven changes in species richness, diversity, and composition across ontogeny. We then used Bayesian predictive trait modeling to assess how species responded to disturbance and how this might influence the functional structure of the plant community. Our results show decreased seedling richness after hurricane disturbance, as well as increased sapling richness and diversity after warming. We found a shift in species composition through time for both seedlings and saplings, yet the individual effects of each disturbance were not significant. At both ontogenetic stages, we observed about twice as many species responding to experimental warming as those responding to drought and hurricanes. Predicted changes in functional structure point to disturbance-driven functional shifts toward a mixture of fast-growing and drought-tolerant species. Our findings demonstrate that the tropical forest understory community is more resistant to climatic stressors than expected, especially at the sapling stage. However, early signs of changes in species composition suggest that, in a warming climate with frequent droughts and hurricanes, plant communities might shift over time toward fast-growing or drought-tolerant species.