Data from: Environmental correlates of the Late Quaternary regional extinctions of large and small Palaearctic mammals
收藏资源简介:
Most studies of mammal extinctions during the Pleistocene–Holocene transition explore the relative effects of climate change vs. human impacts on these extinctions, but the relative importance of the different environmental factors involved remains poorly understood. Moreover, these studies are strongly biased towards megafauna, which may have been more influenced by human hunting than species of small body size. We examined the potential environmental causes of Pleistocene–Holocene mammal extinctions by linking regional environmental characteristics with the regional extinction rates of large and small mammals in 14 Palaearctic regions. We found that regional extinction rates were larger for megafauna, but extinction patterns across regions were similar for both size groups, emphasizing the importance of environmental change as an extinction factor as opposed to hunting. Still, the bias towards megafauna extinctions was larger in Southern Europe and smaller in central Eurasia. The loss of suitable habitats, low macroclimatic heterogeneity within regions and an increase in precipitation were identified as the strongest predictors of regional extinction rates. Suitable habitats for many species of the Last Glacial fauna were grassland and desert, but not tundra or forest. The low-extinction regions identified in central Eurasia are characterized by the continuous presence of grasslands and deserts until the present. In contrast, forest expansion associated with an increase in precipitation and temperature was likely the main factor causing habitat loss in the high-extinction regions. The shift of grassland into tundra also contributed to the loss of suitable habitats in northern Eurasia. Habitat loss was more strongly related to the extinctions of megafauna than of small mammals. Ungulate species with low tolerance to deep snow were more likely to go regionally extinct. Thus, the increase in precipitation at the Pleistocene–Holocene transition may have also directly contributed to the extinctions by creating deep snow cover which decreases forage availability in winter.
现有针对更新世-全新世过渡期哺乳动物灭绝的研究,多聚焦气候变化与人类活动对物种灭绝的相对影响,但学界对其中涉及的各类环境因子的相对重要性仍未明确。此外,此类研究存在显著的巨型动物群(megafauna)偏向性:相较于小型哺乳类,巨型动物群可能更易受到人类狩猎活动的影响。本研究通过将14个古北界(Palaearctic)区域的环境特征与该区域内大、小型哺乳动物的区域灭绝率相关联,探讨了更新世-全新世过渡期哺乳动物灭绝的潜在环境成因。研究结果显示,巨型动物群的区域灭绝率更高,但两类体型哺乳动物的区域灭绝模式却较为相似,这凸显了环境变化而非狩猎活动作为灭绝驱动因子的重要性。不过,巨型动物群灭绝的偏向性在南欧更为显著,而在欧亚大陆中部则相对较弱。适宜栖息地丧失、区域内大气候异质性偏低以及降水量增加,被确定为区域灭绝率最强的预测因子。末次冰期动物群(Last Glacial fauna)多数物种的适宜栖息地为草原与荒漠,而非苔原或森林。本研究在欧亚大陆中部识别出的低灭绝区域,其特征为直至现今仍持续保留草原与荒漠生态系统。与之相反,伴随降水量与气温上升而发生的森林扩张,可能是高灭绝区域栖息地丧失的主要驱动因素。草原向苔原的转变,也加剧了欧亚大陆北部适宜栖息地的丧失。相较于小型哺乳动物,栖息地丧失与巨型动物群灭绝的关联性更强。对深雪耐受度较低的有蹄类动物(ungulates),更易发生区域性灭绝。因此,更新世-全新世过渡期降水量的增加,可能通过形成深雪覆盖、降低冬季饲草可获得性,直接推动了物种灭绝进程。




