Curd Amelia, Chevalier Mathieu, Vasquez Mickaël, Boyé Aurélien, Firth Louise B, Marzloff Martin P, Bricheno Lucy M, Burrows Michael T, Bush Laura E, Cordier Céline, Davies Andrew J, Green J A Mattias, Hawkins Stephen J, Lima Fernando P, Meneghesso Claudia, Mieszkowska Nova, Seabra Rui, Dubois Stanislas F
IFREMER, Centre de Bretagne, DYNECO LEBCO, Plouzané, France.
School of Biological and Marine Sciences, University of Plymouth, Drake Circus, Plymouth, UK.
Glob Chang Biol. 2023 Feb;29(3):631-647. doi: 10.1111/gcb.16496. Epub 2022 Nov 17.
Distributional shifts in species ranges provide critical evidence of ecological responses to climate change. Assessments of climate-driven changes typically focus on broad-scale range shifts (e.g. poleward or upward), with ecological consequences at regional and local scales commonly overlooked. While these changes are informative for species presenting continuous geographic ranges, many species have discontinuous distributions-both natural (e.g. mountain or coastal species) or human-induced (e.g. species inhabiting fragmented landscapes)-where within-range changes can be significant. Here, we use an ecosystem engineer species (Sabellaria alveolata) with a naturally fragmented distribution as a case study to assess climate-driven changes in within-range occupancy across its entire global distribution. To this end, we applied landscape ecology metrics to outputs from species distribution modelling (SDM) in a novel unified framework. SDM predicted a 27.5% overall increase in the area of potentially suitable habitat under RCP 4.5 by 2050, which taken in isolation would have led to the classification of the species as a climate change winner. SDM further revealed that the latitudinal range is predicted to shrink because of decreased habitat suitability in the equatorward part of the range, not compensated by a poleward expansion. The use of landscape ecology metrics provided additional insights by identifying regions that are predicted to become increasingly fragmented in the future, potentially increasing extirpation risk by jeopardising metapopulation dynamics. This increased range fragmentation could have dramatic consequences for ecosystem structure and functioning. Importantly, the proposed framework-which brings together SDM and landscape metrics-can be widely used to study currently overlooked climate-driven changes in species internal range structure, without requiring detailed empirical knowledge of the modelled species. This approach represents an important advancement beyond predictive envelope approaches and could reveal itself as paramount for managers whose spatial scale of action usually ranges from local to regional.
物种分布范围的变化为生态系统对气候变化的响应提供了关键证据。对气候驱动变化的评估通常集中在大规模的范围变化（例如向极地或向上），而区域和地方尺度上的生态后果通常被忽视。虽然这些变化对于呈现连续地理分布范围的物种来说是有参考价值的，但许多物种具有不连续的分布——包括自然形成的（如山地或沿海物种）或人为造成的（如栖息在破碎化景观中的物种）——在其分布范围内的变化可能很大。在这里，我们以一种具有自然破碎化分布的生态系统工程师物种（蜂窝沙蚕）为例，评估气候驱动的其全球分布范围内占有率的变化。为此，我们在一个新颖的统一框架中，将景观生态学指标应用于物种分布模型（SDM）的输出结果。SDM预测，到2050年，在RCP 4.5情景下，潜在适宜栖息地面积将总体增加27.5%，仅从这一点来看，该物种会被归类为气候变化的赢家。SDM还进一步揭示，由于分布范围赤道部分栖息地适宜性下降，预计纬度范围会缩小，且不会因向极地扩展而得到补偿。景观生态学指标的使用通过识别预计未来会变得日益破碎化的区域，提供了更多见解，这可能会通过危及集合种群动态而增加灭绝风险。这种分布范围破碎化的加剧可能会对生态系统结构和功能产生巨大影响。重要的是，所提出的将SDM和景观指标结合在一起的框架，可以广泛用于研究目前被忽视的气候驱动的物种内部范围结构变化，而无需对建模物种有详细的实证知识。这种方法代表了超越预测包络方法的重要进步，对于行动空间尺度通常从地方到区域的管理者来说可能至关重要。
