Climate change is predicted to impact the global distribution and richness of pines (genus Pinus) by 2070

Aim: Climate change is altering habitat suitability for many organisms and modifying species ranges at a global scale. Here we explored the impact of climate change on 112 pine species (Pinus), fundamental elements of Northern terrestrial ecosystems.

Location: Global.

Methods: We applied a novel methodology for species distribution modelling that considers uncertainty in climatic projections and taxon sampling, and incorporates elements of species’ recent evolutionary history. We based our niche calculations on climate and soil data and computed projections across multiple algorithms and IPCC scenarios, which were ensembled into one single suitability map. We then used phylogenetic methods to account for recent evolution in climatic requirements by estimating the evolution of climatic niche. Edaphoclimatic and evolutionary analyses were then combined to calibrate the projections in areas showing high uncertainty. We validated our models using naturalized occurrences of invasive pine species.

Results: Our models predicted that by 2070 most pine species (58%) might face important reductions of habitat suitability, potentially leading to range losses and a decrease in species richness, particularly in some regions such as the Mediterranean Basin and South North America, albeit migration might mitigate these shifts in some cases. In contrast, our projections showed increased habitat suitability for approx. 20% of species, which may undergo range expansions under climate change. Moreover, the consideration of recent evolutionary trends modified projected scenarios, decreasing range loss and increasing range expansion for some species. The independent validation endorsed our models for many species and the influence of recent evolution in some cases.

Conclusions: We predict that climate change will impose drastic changes in pine distribution and diversity across biogeographical regions, but the magnitude and direction of change will vary significantly across regions and taxa. Species-level responses are likely to be influenced by regional conditions and the recent evolutionary history of each taxon.

**研究目的**：气候变化正以全球尺度改变诸多生物的栖息地适宜性，并重塑物种种群的分布范围。本研究聚焦北半球陆地生态系统的基础组成类群——112种松属（Pinus）植物，探讨气候变化对其产生的影响。

**研究区域**：全球范围。

**研究方法**：本研究采用一种全新的物种分布建模（species distribution modelling）方法，该方法可考量气候预测与类群采样中的不确定性，并纳入物种近期演化历史相关要素。本研究基于气候与土壤数据开展生态位（niche）计算，结合多种算法与政府间气候变化专门委员会（IPCC，Intergovernmental Panel on Climate Change）情景开展分布投影，并将多模型结果集成为单一的栖息地适宜性分布图。随后，通过系统发育学（phylogenetic）方法估算气候生态位的演化历程，以此纳入物种近期演化在气候需求方面的影响。此外，本研究结合土壤-气候（edaphoclimatic）与演化分析手段，对不确定性较高的区域的预测结果进行校准。最后，利用归化入侵松类物种的自然分布记录对模型进行独立验证。

**研究结果**：本模型预测，至2070年，多数松属物种（58%）的栖息地适宜性可能出现显著下降，进而可能导致其分布范围缩减以及区域物种丰富度降低，这一效应在地中海盆地、北美洲南部等区域尤为突出；不过部分情况下物种的迁移可缓解此类分布变化。与之相对，本研究预测约20%的物种的栖息地适宜性将得到提升，这类物种在气候变化情境下可能实现分布范围扩张。此外，纳入近期演化趋势的分析修正了原预测情景，使得部分物种的分布范围缩减幅度降低、扩张幅度提升。独立验证结果表明，本模型对多数物种的预测效果良好，且部分物种的响应确实受到近期演化历程的影响。

**研究结论**：本研究预测，气候变化将对全球各生物地理区域内松属植物的分布与多样性造成剧烈改变，但变化的幅度与方向在不同区域与类群间存在显著差异。物种种群的响应可能受区域环境条件以及各分类单元自身近期演化历史的共同调控。