Department of Fisheries and Environmental Sciences, Faculty of Natural Resources and Earth Sciences, Shahrekord University, 8818634141 Shahrekord, Iran.
Department of Natural Resources and Environmental Engineering, School of Agriculture, Shiraz University, 71441-13131 Shiraz, Iran.
Sci Total Environ. 2022 Sep 1;837:155753. doi: 10.1016/j.scitotenv.2022.155753. Epub 2022 May 6.
Climate change is one of the major challenges to the current conservation of biodiversity. Here, by using the brown bear, Ursus arctos, in the southernmost limit of its global distribution as a model species, we assessed the impact of climate change on the species distribution in western Iran. The mountainous forests of Iran are inhabited by small and isolated populations of brown bears that are prone to extinction in the near future. We modeled the potential impact of climate change on brown bear distribution and habitat connectivity by the years 2050 and 2070 under four representative concentration pathways (RCPs) of two general circulation models (GCMs): BCC-CSM1-1 and MRI-CGCM3. Our projections revealed that the current species' range, which encompasses 6749.8 km (40.8%) of the landscape, will decline by 10% (2050: RCP2.6, MRI-CGCM3) to 45% (2070: RCP8.5, BCC-CSM1-1). About 1850 km (27.4%) of the current range is covered by a network of conservation (CAs) and no-hunting (NHAs) areas which are predicted to decline by 0.64% (2050: RCP2.6, MRI-CGCM3) to 15.56% (2070: RCP8.5, BCC-CSM1-1) due to climate change. The loss of suitable habitats falling within the network of CAs and NHAs is a conservation challenge for brown bears because it may lead to bears moving outside the CAs and NHAs and result in subsequent increases in the levels of bear-human conflict. Thus, re-evaluation of the network of CAs and NHAs, establishing more protected areas in suitable landscapes, and conserving vital linkages between habitat patches under future climate change scenarios are crucial strategies to conserve and manage endangered populations of the brown bear.
气候变化是当前生物多样性保护面临的主要挑战之一。在这里，我们以分布在全球最南端的棕熊（Ursus arctos）为模型物种，评估了气候变化对伊朗西部物种分布的影响。伊朗多山的森林中栖息着数量较少且孤立的棕熊种群，它们在不久的将来很容易灭绝。我们利用两种通用环流模型（GCMs）的四个代表性浓度途径（RCPs），模拟了 2050 年和 2070 年气候变化对棕熊分布和栖息地连通性的潜在影响：BCC-CSM1-1 和 MRI-CGCM3。我们的预测显示，当前物种的分布范围（占景观的 6749.8 公里，占 40.8%）将减少 10%（2050 年：RCP2.6，MRI-CGCM3）到 45%（2070 年：RCP8.5，BCC-CSM1-1）。目前的分布范围内约有 1850 公里（占 27.4%）覆盖着保护（CA）和禁猎（NHA）区网络，由于气候变化，预计这一数字将减少 0.64%（2050 年：RCP2.6，MRI-CGCM3）到 15.56%（2070 年：RCP8.5，BCC-CSM1-1）。由于气候变化，CA 和 NHA 网络内适宜栖息地的丧失对棕熊来说是一个保护挑战，因为这可能导致棕熊离开 CA 和 NHA，从而导致人与熊之间的冲突水平上升。因此，重新评估 CA 和 NHA 网络，在适宜的景观中建立更多的保护区，以及在未来的气候变化情景下保护栖息地斑块之间的重要联系，是保护和管理濒危棕熊种群的关键策略。
