Ecological 'Tipping Points'? - How invasion of a potential canopy dominant affects landscape-scale ecosystem patterns

生态“临界点”？

• 批准号: NE/I011234/1
• 负责人: Brian Huntley
• 金额: $ 52.03万
• 依托单位: Durham University
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2012
• 资助国家: 英国
• 起止时间: 2012 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=NE%2FI011234%2F1
• 关键词: Ecological; Tipping; Points; How; invasion

When climatic conditions change by a relatively large amount and relatively rapidly, as they are projected to do this century, species' principal response is to adjust their geographical distributions so that they continue to occupy areas with suitable conditions. As a result, species invade regions and landscapes where they previously were absent. In the case of species with the potential to be ecosystem dominants (e.g. trees that can dominate forest canopies), such invasions are likely to lead to marked changes in the ecosystems of the invaded area. Most landscapes support a range of ecosystems occupying areas differing in environmental conditions because of the relief of the landscape or the presence of different substrates for soil development. Such heterogeneity contributes to the ability of a landscape to support a range of species, biodiversity being higher in more heterogeneous landscapes. This heterogeneity also enables a wider range of species to move through the landscape as they respond to climatic changes. More homogeneous landscapes, or those where some habitat types have been lost, act as barriers to the movement of species and thus limit their ability to adapt to climatic change. Reliable projections are needed of how invasions by potential ecosystem dominants may affect ecosystem patterns and landscape heterogeneity. Such projections will inform the development of landscape management plans and biodiversity conservation strategies that together will maximise species' opportunities to adapt to climatic changes. We will collect data documenting the impacts of a past invasion on ecosystem patterns in three landscapes. We will apply the techniques of palaeoecology, principally pollen analysis and radiocarbon dating, to sediments that have accumulated in small basins in the landscapes since the end of the last glacial stage. By examining a series of such small basins in each landscape, as well as one larger basin in each case, we will obtain records of the changing composition of individual stands of vegetation, as well as records of the shifting regional vegetation composition. Together, these data will allow us to reconstruct ecosystem patterns on the landscapes through time. We will focus our attention on the invasion of Scots Pine into the Western Highlands of Scotland between about 8800 and 5800 years ago. Prior to this invasion the forests of this region generally had mixed canopies of Oak and Elm, with a Hazel understorey. Some stands of such mixed woodland persist, but Pine now dominates most of the remaining forests. The data we will collect will allow us to determine which parts of the landscape Pine invaded and how its invasion impacted upon ecosystem patterns and overall landscape heterogeneity. We will also use a state-of-the-art vegetation model to simulate the Pine invasion. This model uses as inputs, amongst other things, simulations of climatic conditions during the period when the invasion took place. We will compare simulated changes in ecosystem character and patterns on the landscapes associated with the invasion with patterns reconstructed from the palaeovegetation data. This will enable us to evaluate the model's ability reliably to simulate the consequences of such an invasion. This is important because such models provide one of the few tools available to project the potential consequences of invasions arising from species' responses to anthropogenic climatic change. In order to illustrate its potential for such applications, we will apply the model to simulate one such potential future invasion of a canopy dominant tree into these landscapes. Our results will be of direct relevance to various stakeholders, informing the development of landscape management and biodiversity conservation strategies. We will ensure that they are communicated to such stakeholders, as well as to the scientific community and to the wider public.

当气候条件变化相对较大且相对较快（预计本世纪）时，物种的主要反应是调整其地理分布，以便它们继续占据适当条件的区域。结果，物种入侵了以前没有的地区和景观。对于具有生态系统主导因素的物种（例如，可以主导森林檐篷的树木），这种入侵可能会导致入侵区域的生态系统发生明显变化。大多数景观都支持一系列生态系统占据环境条件不同的地区，因为景观的缓解或存在不同的底物以进行土壤发育。这种异质性有助于景观支持一系列物种，在更异质的景观中生物多样性较高。这种异质性还使更广泛的物种在响应气候变化时可以通过景观移动。更均匀的景观，或者丢失了一些栖息地类型的景观，是物种运动的障碍，从而限制了它们适应气候变化的能力。需要可靠的预测，即潜在的生态系统主导力可能影响生态系统模式和景观异质性。这样的预测将为景观管理计划和生物多样性保护策略的制定提供信息，这些策略将共同提高物种适应气候变化的机会。我们将收集记录过去入侵对三种景观生态系统模式的影响的数据。我们将应用古生态学的技术，主要是花粉分析和放射性碳年代的技术，以自上次冰川阶段结束以来在景观中积累的沉积物。通过检查每个景观中的一系列小盆地，以及在每种情况下一个较大的盆地，我们将获得各个植被林分的成分的记录，以及不断变化的区域植被组成的记录。这些数据一起将使我们能够随着时间的推移在景观上重建生态系统模式。我们将把注意力集中在大约8800年至5800年前的苏格兰派恩（Scots Pine）进入苏格兰西部高地的。在入侵之前，该地区的森林通常具有橡木和榆树的混合檐篷，并带有榛树底层。这种混合林地的某些摊位持续存在，但派恩现在占据了其余的大多数森林。我们将收集的数据将使我们能够确定景观松树的哪些部分入侵，其入侵如何影响生态系统模式和整体景观异质性。我们还将使用最先进的植被模型来模拟松树的入侵。该模型在进行入侵期间用作输入的气候状况模拟。我们将比较与入侵相关的景观中生态系统特征的模拟变化，并与从古植物数据中重建的模式进行比较。这将使我们能够可靠地评估模型的能力，以模拟这种入侵的后果。这很重要，因为这样的模型提供了可用于投影物种对人为气候变化的反应引起的入侵后果的少数工具之一。为了说明其用于此类应用的潜力，我们将应用该模型来模拟一种可能将来对树冠占主导地位的潜在入侵到这些景观中的潜在入侵。我们的结果将与各种利益相关者直接相关，并告知景观管理和生物多样性保护策略的发展。我们将确保将他们传达给此类利益相关者，以及科学界和更广泛的公众。

项目成果

Holocene expansion of the Caledonian pinewoods: spatial and temporal patterns at regional and landscape scales

喀里多尼亚松林的全新世扩张：区域和景观尺度的时空格局

• DOI: 10.1080/17550874.2021.1984601
• 发表时间: 2021
• 期刊: Plant Ecology & Diversity
• 影响因子: 1.5
• 作者: Huntley B

Joint palaeoclimate reconstruction from pollen data via forward models and climate histories

通过正演模型和气候历史从花粉数据联合重建古气候

• DOI: 10.1016/j.quascirev.2016.09.007
• 发表时间: 2016
• 期刊: Quaternary Science Reviews
• 影响因子: 4
• 作者: Parnell A

Bayesian Inference for Palaeoclimate with time Uncertainty and Stochastic Volatility

古气候随时间不确定性和随机波动的贝叶斯推断

• DOI: 10.1111/rssc.12065
• 发表时间: 2015
• 期刊: Applied Statistics
• 作者: Parnell A

Frequency selection in paleoclimate time series: A model-based approach incorporating possible time uncertainty

古气候时间序列中的频率选择：基于模型的方法，考虑了可能的时间不确定性

• DOI: 10.1002/env.2492
• 发表时间: 2018
• 期刊: Environmetrics
• 影响因子: 1.7
• 作者: Franke P

Climatic Disequilibrium Threatens Conservation Priority Forests

气候不平衡威胁着​​优先森林保护

• DOI: 10.1111/conl.12349
• 发表时间: 2017
• 期刊: Conservation Letters
• 影响因子: 8.5
• 作者: Huntley B