Journal of Ecology ( IF 5.3 ) Pub Date : 2022-08-08 , DOI: 10.1111/1365-2745.13978 Jorge Aldea 1 , Ricardo Ruiz‐Peinado 2, 3 , Miren del Río 2, 3 , Hans Pretzsch 4 , Michael Heym 4 , Gediminas Brazaitis 5 , Aris Jansons 6 , Marek Metslaid 7 , Ignacio Barbeito 8 , Kamil Bielak 9 , Gro Hylen 10 , Stig‐Olof Holm 11 , Arne Nothdurft 12 , Roman Sitko 13 , Magnus Löf 1
|
1 INTRODUCTION
Drought kills trees across Europe, affecting carbon balance and other ecosystem functions (Anderegg et al., 2015; Senf et al., 2020). Climate change is increasing the frequency of droughts, their intensity and duration around the globe, and European forests have recently endured unprecedented drought events (Buras et al., 2020; Spinoni et al., 2018). Drought stress predisposes trees to forest fires and damage from pest and diseases, leading to an emerging vulnerability of European forests (Forzieri et al., 2021). Therefore, new management strategies to increase forest drought resilience are urgently needed (DeSoto et al., 2020).
Drought frequency, intensity, duration and timing all affect tree growth (Anderegg et al., 2020; Bose et al., 2021; D'Orangeville et al., 2018), but their interactions are poorly understood. Huang et al. (2018) found that droughts during the dry season (DS) normally last longer and have larger impacts compared to droughts during other seasons. Trees with greater pre-drought growth can be more affected by long and intense droughts (Bose et al., 2020). In addition, other intrinsic and environmental drivers could modulate the impact of drought on growth (D'Orangeville et al., 2018). Intrinsic attributes include tree size, population age structure, species richness, evenness and diversity of communities. Extrinsic drivers are characteristics of the trees' environment such as topography and soil (Nimmo et al., 2015). Recent studies show that the tree response to extreme climate events may vary based on individual characteristics such as tree size or competition pressure (Nepstad et al., 2007; Pretzsch et al., 2018), while others point to minor or species-specific importance (Serra-Maluquer et al., 2021). Therefore, more evidence is needed in this regard.
Recent studies reveal several advantages of mixed over pure stands, including enhanced drought resilience (Fichtner et al., 2020; Jactel et al., 2017). In mixed stands, trees use water and light more efficiently than in single-species stands (Fichtner et al., 2017; Grossiord, 2019). This may result in higher growth and yield (Jactel et al., 2018; Pretzsch & Schütze, 2021), more stable growth (Schnabel et al., 2021), greater ecosystem service provision (Felton et al., 2020) and reduced disturbance impact (Jactel et al., 2017). On average, mixed stands are more resilient to drought than monospecific stands (Jansen et al., 2021), but exceptions are common (del Río et al., 2021; Forrester et al., 2016). Tree growth response to drought depends on the identity of neighbouring species and forest structure (Pardos et al., 2021). Therefore, which species combinations are more resilient to drought is an important question that needs more investigation.
Understanding the effects of perturbations on ecosystems requires the simultaneous measurement of multiple components of stability (Ingrisch & Bahn, 2018). Various indices used to characterize tree growth resilience to drought have been widely discussed in literature (van der Maaten-Theunissen et al., 2021). The most commonly used indices for this purpose have drawbacks and limitations which may lead to misleading results or misinterpretation of observed patterns (Schwarz et al., 2020). Therefore, the way in which growth-based resilience indices are calculated and how intrinsic and environmental predictors are considered are important factors for correctly evaluating tree growth response to drought.
Forests in most of Europe are dominated by two coniferous tree species: Norway spruce (Picea abies (L.) Karst) and Scots pine (Pinus sylvestris L.). They are widely distributed (Figure SM1), have great ecological significance and are of major commercial importance for European forestry. Low summer water availability combined with high temperatures strongly reduces growth for both of these species, suggesting that they may be unable to cope with prolonged and frequent dry conditions in Europe (Lévesque et al., 2014; Zang et al., 2012). In fact, there is clear evidence that extreme growth reductions (GRs) due to drought in Europe increased after 1990 for both species (Treml et al., 2021). Norway spruce is regarded as more vulnerable to drought than other coexisting species (Pretzsch et al., 2020; Vitasse et al., 2019; Zang et al., 2014), with significant wood damage and economic loss (Rosner et al., 2018). Accordingly, Treml et al. (2021) showed that Norway spruce is more vulnerable to drought than Scots pine at low altitudes in Central Europe. Other studies have shown that both Scots pine and Norway spruce can benefit from mixtures with other species (Pardos et al., 2021; Pretzsch et al., 2020), but it is still not known how these two species will respond to drought when growing together.
In this study, we used tree-ring data from 22 sites covering a large part of the distribution ranges of Scots pine and Norway spruce in Europe. We analysed their tree-level growth responses to drought in mixed and pure stands to identify: (1) differences in species-specific growth responses, (2) differences in tree-growth response to drought between mixed and pure stands and (3) how drought characteristics (intensity, duration and timing) and other environmental and intrinsic factors influence tree growth responses. Our ultimate goal is to better understand and identify the individual tree, site and environmental conditions which influence growth resilience to drought in Scots pine and Norway spruce.
中文翻译：
干旱的时间和持续时间调节苏格兰松和挪威云杉纯林和混合林的树木生长反应
1 简介
干旱杀死了整个欧洲的树木，影响碳平衡和其他生态系统功能（Anderegg 等人， 2015 年；Senf 等人， 2020 年）。气候变化正在增加全球干旱的频率、强度和持续时间，欧洲森林最近经历了前所未有的干旱事件（Buras 等人， 2020 年；Spinoni 等人， 2018 年）。干旱胁迫使树木容易遭受森林火灾和病虫害的破坏，导致欧洲森林日益脆弱（Forzieri 等人， 2021 年）。因此，迫切需要新的管理策略来提高森林的抗旱能力（DeSoto 等人， 2020 年）。
干旱频率、强度、持续时间和时间都会影响树木的生长（Anderegg 等人， 2020 年；Bose 等人， 2021 年；D'Orangeville 等人， 2018 年），但它们之间的相互作用却知之甚少。黄等人。（2018 年）发现，与其他季节的干旱相比，旱季（DS）的干旱通常持续时间更长，影响更大。干旱前生长较大的树木可能更容易受到长期严重干旱的影响（Bose 等人， 2020 年）。此外，其他内在和环境驱动因素可能会调节干旱对增长的影响（D'Orangeville 等， 2018）。内在属性包括树木大小、种群年龄结构、物种丰富度、群落的均匀性和多样性。外在驱动因素是树木环境的特征，例如地形和土壤（Nimmo 等人， 2015 年）。最近的研究表明，树木对极端气候事件的反应可能因树木大小或竞争压力等个体特征而异（Nepstad 等人， 2007 年；Pretzsch 等人， 2018 年），而其他人则指出次要或特定物种的重要性（Serra-Maluquer 等人， 2021 年）。因此，这方面需要更多的证据。
最近的研究揭示了混合林分优于纯林分的几个优点，包括增强的抗旱能力（Fichtner 等人， 2020 年；Jactel 等人， 2017 年）。在混合林分中，树木比单一林分更有效地利用水和光（Fichtner 等人， 2017 年；Grossiord， 2019 年）。这可能会导致更高的增长和产量（Jactel 等人， 2018 年；Pretzsch & Schütze， 2021 年）、更稳定的增长（Schnabel 等人， 2021 年）、更大的生态系统服务提供（Felton 等人， 2020 年）和减少干扰影响（Jactel 等人， 2017）。平均而言，混合林分比单一林分更能抵御干旱（Jansen 等人， 2021 年），但也有例外情况（del Río 等人， 2021 年；Forrester 等人， 2016 年）。树木对干旱的生长反应取决于邻近物种的特性和森林结构（Pardos 等人， 2021 年）。因此，哪些物种组合更能抵御干旱是一个需要更多研究的重要问题。
了解扰动对生态系统的影响需要同时测量稳定性的多个组成部分（Ingrsch & Bahn， 2018 年）。文献中广泛讨论了用于表征树木生长抗旱能力的各种指标（van der Maaten-Theunissen 等人， 2021 年）。为此目的最常用的指数存在缺陷和局限性，可能会导致误导性结果或对观察到的模式的误解（Schwarz 等人， 2020 年）。因此，计算基于生长的弹性指数的方式以及如何考虑内在和环境预测因素是正确评估树木生长对干旱反应的重要因素。
欧洲大部分地区的森林以两种针叶树种为主：挪威云杉 ( Picea abies (L.) Karst) 和苏格兰松 ( Pinus sylvestris L.)。它们分布广泛（图 SM1），具有重要的生态意义，对欧洲林业具有重要的商业意义。夏季用水量低加上高温严重降低了这两种物种的生长，这表明它们可能无法应对欧洲长期和频繁的干旱条件（Lévesque 等人， 2014 年；Zang 等人， 2012 年）。事实上，有明确的证据表明，1990 年后欧洲干旱导致的极端生长减少 (GRs) 对这两个物种都有所增加（Treml 等人， 2021）。挪威云杉被认为比其他并存的树种更容易受到干旱的影响（Pretzsch 等人， 2020 年；Vitasse 等人， 2019 年；Zang 等人， 2014 年），造成严重的木材破坏和经济损失（Rosner 等人， 2018 年） ）。因此，Treml 等人。（2021 年）表明，在中欧低海拔地区，挪威云杉比苏格兰松更容易受到干旱的影响。其他研究表明，苏格兰松和挪威云杉都可以从与其他物种的混合中受益（Pardos 等人， 2021 年；Pretzsch 等人， 2020 年），但目前尚不清楚这两个物种在生长时将如何应对干旱一起。
在这项研究中，我们使用了来自 22 个地点的树木年轮数据，涵盖了欧洲苏格兰松和挪威云杉的大部分分布范围。我们分析了它们在混合林分和纯林分中对干旱的树木水平生长反应，以确定：（1）特定物种生长反应的差异，（2）混合林分和纯林分之间树木生长对干旱的反应差异以及（3）如何干旱特征（强度、持续时间和时间）和其他环境和内在因素会影响树木的生长反应。我们的最终目标是更好地了解和识别影响苏格兰松和挪威云杉生长抗旱能力的个体树木、场地和环境条件。
京公网安备 11010802027423号