Can tropical Montane forest Acclimate to high temperature? Montane-Acclim

热带山地森林能适应高温吗？

• 批准号: NE/R001928/1
• 负责人: Lina Mercado
• 金额: $ 83.77万
• 依托单位: UNIVERSITY OF EXETER
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2017
• 资助国家: 英国
• 起止时间: 2017 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=NE%2FR001928%2F1
• 关键词: tropical; Montane; forest; Acclimate; temperature

Tropical forests play a critical role in global water, carbon and nutrient cycles, and currently absorb billions of tonnes of carbon, thus reducing rates of climate change. For this reason, computer models that are used to predict future climate change and the impacts of climate on plants and ecosystems, need to be able to represent tropical forest very well. In fact, the response of tropical forests to changes in temperature is one of the greatest uncertainties in climate change prediction. However, currently, scientists do not understand how these forests will respond to increasing temperatures. This is worrying because temperatures are increasing faster today than in the past, forcing forests to respond to unprecedented rates of warming. Critically, the lack of seasonal changes in temperature may mean that trees growing in these regions have a reduced capacity to deal with rapid climate change compared with more temperate and high-latitude species. If this is the case, then global warming may represent a considerable threat to these forests, the amazing amounts of biodiversity that they contain, and their role in reducing current rates of climate change. However, this suggestion is yet to be tested formally.The lack of understanding is even more worrying for tropical forest growing in mountains, as in these areas temperatures are increasing faster than in the lowlands. For example, scientists studying Andean forest in Colombia and Peru have observed that some tree species native to high elevations are dying out while others are moving to higher elevations. These scientists have suggested that these observations may be explained by the fact that trees are already seeing the impacts of climate change and are not able to withstand current temperatures. However, this explanation remains controversial and has not been tested formally. The major goal of this project is to determine if tropical Andean species can tolerate current temperatures and adjust to withstand the higher temperatures expected for the future. To answer this question, we will plant trees from high elevations in the Colombian Andes in their home environment but also at two lower elevations where temperatures are 5oC and 9oC higher, respectively. Our trees will be all planted in common soils and will have access to plenty of water, eliminating potential differences in water and nutrient access. We will monitor photosynthesis, respiration and growth at the three locations in other to understand how they respond to temperature. Compared to other experiments, our study is unique as it will: i) be the first to investigate the ability of large 3 - 4m tall trees planted in a common soil to respond to long-term (3 year) changes in temperature, ii) investigate a much greater number of species than all other field studies on this subject, and iii) measure a more complete set of key physiological and growth responses than in any other experiment. The measurements taken will be used to the derive mathematical equations that can represent the response of these tree montane species to elevated temperatures. Furthermore, to predict the response of tropical forest everywhere in the world to higher temperatures, we need data from high and low elevations in as many locations as possible. Scientists around the world are now starting to collect some of these measurements in forests from Costa Rica, Puerto Rico, Panama, Brazil, Peru, Rwanda and Australia. Although, no one of these investigations is as detailed as our study, by teaming up with all these groups we can use their data to test and extrapolate our equations across all tropics globally. We will then introduce these mathematical equations into a computer model to predict future behavior of the tropical forest under warming conditions. The outcome will represent a step change in our ability to accurately predict how this critically important biome will respond to global warming.

热带森林在全球水、碳和养分循环中发挥着关键作用，目前吸收了数十亿吨碳，从而降低了气候变化的速度。因此，用于预测未来气候变化以及气候对植物和生态系统影响的计算机模型需要能够很好地代表热带森林。事实上，热带森林对温度变化的反应是气候变化预测中最大的不确定性之一。然而，目前，科学家们还不知道这些森林将如何应对气温上升。这是令人担忧的，因为今天的气温上升速度比过去更快，迫使森林应对前所未有的变暖速度。重要的是，缺乏温度的季节性变化可能意味着与更温和和高纬度的物种相比，生长在这些地区的树木应对快速气候变化的能力降低。如果是这样的话，那么全球变暖可能会对这些森林、它们所包含的惊人数量的生物多样性以及它们在降低目前气候变化速度方面的作用构成相当大的威胁。然而，这一建议尚未得到正式验证。对生长在山区的热带森林缺乏了解更令人担忧，因为这些地区的气温上升速度比低地更快。例如，研究哥伦比亚和秘鲁安第斯森林的科学家们观察到，一些原产于高海拔地区的树种正在灭绝，而另一些树种正在向更高海拔地区迁移。这些科学家认为，这些观察结果可能是因为树木已经看到了气候变化的影响，无法承受目前的温度。然而，这一解释仍然存在争议，并没有得到正式的检验。该项目的主要目标是确定热带安第斯物种是否能够承受目前的温度，并适应未来预期的更高温度。为了回答这个问题，我们将在哥伦比亚安第斯山脉的高海拔地区种植树木，同时也在两个较低的海拔地区种植树木，那里的温度分别高出5摄氏度和9摄氏度。我们的树木将全部种植在共同的土壤中，并将获得充足的水，消除水和养分获取的潜在差异。我们将在其他三个地点监测光合作用、呼吸作用和生长，以了解它们对温度的反应。与其他实验相比，我们的研究是独一无二的，因为它将：i）是第一个调查种植在普通土壤中的3 - 4米高的大树对长期（3年）温度变化的反应能力的人，ii）调查的物种数量比关于这个问题的所有其他实地研究都要多得多，和iii）测量比任何其它实验更完整的一组关键生理和生长反应。所采取的测量将被用来推导数学方程，可以代表这些树山地物种的反应，以升高的温度。此外，为了预测世界各地热带森林对高温的反应，我们需要尽可能多的地点的高海拔和低海拔的数据。世界各地的科学家现在开始收集来自哥斯达黎加、波多黎各、巴拿马、巴西、秘鲁、卢旺达和澳大利亚的森林中的一些测量数据。虽然这些调查中没有一项像我们的研究那样详细，但通过与所有这些团体合作，我们可以使用他们的数据来测试和推断我们在全球所有热带地区的方程。然后，我们将把这些数学方程引入计算机模型中，以预测热带森林在变暖条件下的未来行为。这一结果将代表我们准确预测这一至关重要的生物群落将如何应对全球变暖的能力发生了重大变化。

项目成果

Differential nutrient limitation and tree height control leaf physiology, supporting niche partitioning in tropical dipterocarp forests

• DOI: 10.1111/1365-2435.14094
• 发表时间: 2022-06-29
• 期刊: FUNCTIONAL ECOLOGY
• 影响因子: 5.2
• 作者: Bartholomew, David C.;Banin, Lindsay F.;Rowland, Lucy
• 通讯作者: Rowland, Lucy

Acclimation of photosynthetic capacity and foliar respiration in Andean tree species to temperature change.

安第斯树种光合能力和叶呼吸对温度变化的适应。

• DOI: 10.1111/nph.18900
• 发表时间: 2023
• 期刊: The New phytologist
• 作者: Cox AJF

Nocturnal plant respiration is under strong non-temperature control.

• DOI: 10.1038/s41467-022-33370-1
• 发表时间: 2022-09-26
• 期刊: Nature communications
• 影响因子: 16.6

Large sensitivity in land carbon storage due to geographical and temporal variation in the thermal response of photosynthetic capacity.

• DOI: 10.1111/nph.15100
• 发表时间: 2018-06
• 期刊: The New phytologist
• 作者: Mercado LM;Medlyn BE;Huntingford C;Oliver RJ;Clark DB;Sitch S;Zelazowski P;Kattge J;Harper AB;Cox PM
• 通讯作者: Cox PM

Quantifying the temperature independent controls of nocturnal plant respiration

量化夜间植物呼吸的温度独立控制

• 发表时间: 2020
• 作者: Freya Newman