Perilous life at the xeric edge: drought-induced tree mortality in the Mediterranean

干旱边缘的危险生命：地中海干旱导致的树木死亡

• 批准号: NE/I011749/1
• 负责人: Maurizio Mencuccini
• 金额: $ 53.23万
• 依托单位: University of Edinburgh
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2011
• 资助国家: 英国
• 起止时间: 2011 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=NE%2FI011749%2F1
• 关键词: Perilous; life; xeric; edge; drought

During the recent two decades, drought has increased in intensity and frequency in some parts of the world and, in particular, in much of the Mediterranean. While many of the drought-adapted species of the Mediterranean have been reported to show reduced growth rates, the worry lies mostly with species, such as Scots pine, which are present across many of the mountain ranges of the Mediterranean (Pyrenees, Alps, Balcans, Anatolia), but are not really drought-adapted species. As a consequence, species such as Scots pine are currently the focus of much attention, as it has been shown to suffer from extensive mortality across the whole of the Mediterranean, with reported episodes of mortality spanning from Spain, Italy, Switezerland, Austria, Hungary up to Greece and Turkey. Many of these forests are now turning into scrublands consisting of small oaks and juniper, which possess a much higher resistance to drought, but with unknown consequences on the carbon and water cycles of these new ecosystems. In addition, the mortality of these forests is expected to accelerate in future decades, because increased drought is forecast as a result of climate change. Forests carry out a very important role in these countries, by regulating the water supply to the crowded cities of the coast. Forests in countries around the Mediterranean Sea are estimated to provide fundamental ecosystem services to ~0.4 billion people. Water supply in particular is dependent on the health, structure and functioning of forests, with the number of water-poor Mediterranean people now reaching ~180 million inhabitants. We aim to study the physiological causes underlining the observed processes of mortality for Scots pine across three sites spanning the whole of the Mediterranean, i.e., Spain, Switzerland and Turkey. This is of interest because 1) we need to understand exactly why trees die, and 2) we need to learn how to represent these mortality processes in global models, which are currently only very crudely include these processes. We also aim to study the degree by which the adaptations to heat and drought of this species vary across its various populations. For example, we want to know whether some of the populations from southern Scots pine (e.g., in Spain) are more adapted to heat and drought than more Nordic populations of Poland and of Finland. Because the range of this species is forecast to spread further north, it is of interest to understand whether the existing populations at any location in Europe will be well suited to the changed climatic conditions, or whether more Sourtherly populations will have to migrate Northward as the climate also shifts Northward. The findings of this project have direct interest to the strategies of conservation for other European countries, including the UK, because almost all plant species are forecast to move their ranges poleward and upward on the mountains as a result of climate change. In many of these cases, the movement is a direct result of the increased drought and heat conditions prevailing at the so-called trailing edge of the species distribution.

在最近20年里，世界一些地区，特别是地中海大部分地区，干旱的强度和频率都有所增加。虽然据报道，地中海的许多干旱适应物种的生长率下降，但令人担忧的主要是苏格兰松等物种，这些物种遍布地中海的许多山脉（比利牛斯山脉，阿尔卑斯山脉，巴尔坎山脉，安纳托利亚山脉），但并不是真正适应干旱的物种。因此，苏格兰松等物种目前是备受关注的焦点，因为它已被证明在整个地中海遭受广泛的死亡率，据报道，死亡率的事件跨越西班牙，意大利，瑞士，奥地利，匈牙利直到希腊和土耳其。这些森林中的许多现在正在变成由小橡树和杜松组成的灌木丛，它们具有更高的抗旱能力，但对这些新生态系统的碳和水循环产生了未知的后果。此外，预计未来几十年这些森林的死亡率将加快，因为气候变化导致的干旱预计会增加。森林在这些国家发挥着非常重要的作用，调节着沿海拥挤城市的供水。据估计，地中海沿岸国家的森林为约4亿人提供基本的生态系统服务。供水尤其依赖于森林的健康、结构和功能，地中海缺水人口现已达到约1.8亿。我们的目标是研究生理原因强调的死亡过程中观察到的苏格兰松在三个地点跨越整个地中海，即，西班牙、瑞士和土耳其。这很有趣，因为1）我们需要确切地了解树木死亡的原因，2）我们需要学习如何在全局模型中表示这些死亡过程，目前这些模型只是非常粗略地包括这些过程。我们还旨在研究该物种对高温和干旱的适应程度在其不同种群中的差异。例如，我们想知道来自苏格兰南部的一些松树种群（例如，在西班牙）比更多的北欧人口的波兰和芬兰更适应炎热和干旱。由于该物种的分布范围预计将进一步向北扩展，因此有必要了解欧洲任何地点的现有种群是否能够很好地适应变化的气候条件，或者随着气候向北转移，更多的南方种群是否必须向北迁移。该项目的研究结果对包括英国在内的其他欧洲国家的保护战略有直接的意义，因为几乎所有的植物物种都被预测会由于气候变化而在山上向极地和向上移动。在许多情况下，这种迁移是物种分布所谓的后缘普遍存在的干旱和炎热条件增加的直接结果。

项目成果

Coordination of physiological traits involved in drought-induced mortality of woody plants.

• DOI: 10.1111/nph.13461
• 发表时间: 2015-10
• 期刊: The New phytologist
• 作者: Maurizio Mencuccini;F. Minunno;Yann Salmon;J. Martínez‐Vilalta;T. Hölttä

Separating water-potential induced swelling and shrinking from measured radial stem variations reveals a cambial growth and osmotic concentration signal

• DOI: 10.1111/pce.12541
• 发表时间: 2016-02-01
• 期刊: PLANT CELL AND ENVIRONMENT
• 影响因子: 7.3
• 作者: Chan, Tommy;Holtta, Teemu;Nikinmaa, Eero
• 通讯作者: Nikinmaa, Eero

Manipulative experiments demonstrate how long-term soil moisture changes alter controls of plant water use

• DOI: 10.1016/j.envexpbot.2017.12.010
• 发表时间: 2018-08-01
• 期刊: ENVIRONMENTAL AND EXPERIMENTAL BOTANY
• 影响因子: 5.7
• 作者: Grossiord, Charlotte;Sevanto, Sanna;McDowell, Nate G.
• 通讯作者: McDowell, Nate G.

Dwarf trees, super-sized shrubs and scaling: why is plant stature so important?

• DOI: 10.1111/pce.12442
• 发表时间: 2015
• 期刊: Plant, cell & environment
• 作者: Maurizio Mencuccini

An empirical method that separates irreversible stem radial growth from bark water content changes in trees: theory and case studies.

• DOI: 10.1111/pce.12863
• 发表时间: 2017-03
• 期刊: Plant, cell & environment
• 作者: Mencuccini M;Salmon Y;Mitchell P;Hölttä T;Choat B;Meir P;O'Grady A;Tissue D;Zweifel R;Sevanto S;Pfautsch S
• 通讯作者: Pfautsch S