Department of Biology, University of Turku, Turku, 20500, Finland.
Department of Terrestrial Ecology, Norwegian Institute for Nature Research (NINA), P.O. Box 5685 Sluppen, Trondheim, N-7485, Norway.
Conserv Biol. 2021 Jun;35(3):834-845. doi: 10.1111/cobi.13648. Epub 2021 Jan 21.
Climate warming is driving changes in species distributions and community composition. Many species have a so-called climatic debt, that is, shifts in range lag behind shifts in temperature isoclines. Inside protected areas (PAs), community changes in response to climate warming can be facilitated by greater colonization rates by warm-dwelling species, but also mitigated by lowering extirpation rates of cold-dwelling species. An evaluation of the relative importance of colonization-extirpation processes is important to inform conservation strategies that aim for both climate debt reduction and species conservation. We assessed the colonization-extirpation dynamics involved in community changes in response to climate inside and outside PAs. To do so, we used 25 years of occurrence data of nonbreeding waterbirds in the western Palearctic (97 species, 7071 sites, 39 countries, 1993-2017). We used a community temperature index (CTI) framework based on species thermal affinities to investigate species turnover induced by temperature increase. We determined whether thermal community adjustment was associated with colonization by warm-dwelling species or extirpation of cold-dwelling species by modeling change in standard deviation of the CTI (CTI ). Using linear mixed-effects models, we investigated whether communities in PAs had lower climatic debt and different patterns of community change than communities outside PAs. For CTI and CTI combined, communities inside PAs had more species, higher colonization, lower extirpation, and lower climatic debt (16%) than communities outside PAs. Thus, our results suggest that PAs facilitate 2 independent processes that shape community dynamics and maintain biodiversity. The community adjustment was, however, not sufficiently fast to keep pace with the large temperature increases in the central and northeastern western Palearctic. Our results underline the potential of combining CTI and CTI metrics to improve understanding of the colonization-extirpation patterns driven by climate warming.
气候变暖正在推动物种分布和群落组成的变化。许多物种都有一个所谓的气候负债，即范围的变化滞后于温度等距线的变化。在保护区（PAs）内，温暖生境物种的更高定居率可以促进对气候变暖的群落变化，但也可以通过降低寒冷生境物种的灭绝率来缓解。评估定居-灭绝过程的相对重要性对于指导旨在减少气候负债和保护物种的保护策略非常重要。我们评估了气候变暖背景下保护区内外群落变化所涉及的定居-灭绝动态。为此，我们使用了 25 年来在西部古北区（97 个物种，7071 个地点，39 个国家，1993-2017 年）的非繁殖水鸟的出现数据。我们使用了基于物种热亲和性的群落温度指数（CTI）框架来研究由温度升高引起的物种更替。我们通过模拟 CTI 的标准差（CTI ）的变化来确定热群落调整是否与温暖生境物种的定居或寒冷生境物种的灭绝有关。使用线性混合效应模型，我们调查了保护区内的群落是否比保护区外的群落具有更低的气候负债和不同的群落变化模式。对于 CTI 和 CTI 组合，保护区内的群落具有更多的物种、更高的定居率、更低的灭绝率和更低的气候负债（16%），而保护区外的群落则较少。因此，我们的研究结果表明，保护区促进了 2 个独立的过程，这些过程塑造了群落动态并维持了生物多样性。然而，群落的调整速度不够快，无法跟上中西部和东北部西部古北区的大幅度升温。我们的研究结果强调了结合 CTI 和 CTI 指标来提高对气候变暖驱动的定居-灭绝模式的理解的潜力。
