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31.
The climate change risk to biodiversity operates alongside a range of anthropogenic pressures. These include habitat loss and fragmentation, which may prevent species from migrating between isolated habitat patches in order to track their suitable climate space. Predictive modelling has advanced in scope and complexity to integrate: (i) projected shifts in climate suitability, with (ii) spatial patterns of landscape habitat quality and rates of dispersal. This improved ecological realism is suited to data-rich model species, though its broader generalisation comes with accumulated uncertainties, e.g. incomplete knowledge of species response to variable habitat quality, parameterisation of dispersal kernels etc. This study adopts ancient woodland indicator species (lichen epiphytes) as a guild that couples relative simplicity with biological rigour. Subjectively-assigned indicator species were statistically tested against a binary habitat map of woodlands of known continuity (>250 yr), and bioclimatic models were used to demonstrate trends in their increased/decreased environmental suitability under conditions of ‘no dispersal’. Given the expectation of rapid climate change on ecological time-scales, no dispersal for ancient woodland indicators becomes a plausible assumption. The risk to ancient woodland indicators is spatially structured (greater in a relative continental compared to an oceanic climatic zone), though regional differences are weakened by significant variation (within regions) in woodland extent. As a corollary, ancient woodland indicators that are sensitive to projected climate change scenarios may be excellent targets for monitoring climate change impacts for biodiversity at a site-scale, including the outcome of strategic habitat management (climate change adaptation) designed to offset risk for dispersal-limited species. 相似文献
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Sally A. Keith Roger J.H. Herbert Paul A. Norton Stephen J. Hawkins Adrian C. Newton 《Diversity & distributions》2011,17(2):275-286
Aim Evidence indicates that species are responding to climate change through distributional range shifts that track suitable climatic conditions. We aim to elucidate the role of meso‐scale dispersal barriers in climate‐tracking responses. Location South coast of England (the English Channel). Methods Historical distributional data of four intertidal invertebrate species were logistically regressed against sea surface temperature (SST) to determine a climate envelope. This envelope was used to estimate the expected climate‐tracking response since 1990 along the coast, which was compared with observed range expansions. A hydrodynamic modelling approach was used to identify dispersal barriers and explore disparities between expected and observed climate tracking. Results Range shifts detected by field survey over the past 20 years were less than those predicted by the changes that have occurred in SST. Hydrodynamic model simulations indicated that physical barriers produced by complex tidal currents have variably restricted dispersal of pelagic larvae amongst the four species. Main conclusions We provide the first evidence that meso‐scale hydrodynamic barriers have limited climate‐induced range shifts and demonstrate that life history traits affect the ability of species to overcome such barriers. This suggests that current forecasts may be flawed, both by overestimating range shifts and by underestimating climatic tolerances of species. This has implications for our understanding of climate change impacts on global biodiversity. 相似文献
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中国梧桐属(Firmiana)在世界梧桐属中占比较大,且除梧桐外其余种均为中国特有且分布范围狭窄的植物种,灭绝风险大,研究气候变化对中国梧桐属树种的影响对于维护生物多样性具有重要的意义。结合多时期第六次国际气候耦合模式比较计划(CMIP6)气候变量数据和中国八种梧桐属树种的分布数据,基于R语言kuenm程序包优化的最大熵(Maxent)模型模拟分析中国八种梧桐属树种在多尺度下的潜在适生区,得出梧桐属最适宜的模拟尺度、潜在适生区的面积变化和迁移方向、梧桐属多样性保护关键区域及保护空缺。结果表明:(1)梧桐属最适宜的模拟尺度为亚洲;(2) Maxent模型的接收者操作特征曲线下面积(AUC)值均大于0.9,表明模型对梧桐属潜在适生区预测结果具有较高准确度;(3)气候变化影响下除云南梧桐(Firmiana major)外其它树种的潜在适生区都将在未来有所扩大;(4)中国八种梧桐属树种潜在适生区迁移方向主要为东西向,南北向大跨度迁移较少,纬度变化不大;(5)丹霞梧桐(Firmiana danxiaensis)的稳定潜在适生区最小;(6)中国梧桐属多样性保护关键区域主要分布于广西壮族自治区及云南、广东、海南等省区;(7)中国梧桐属多样性保护空缺区域主要分布于广西壮族自治区中部及海南省北部;(8)梧桐属多样性保护关键区域正在为人造地表所侵蚀。研究分析气候变化对中国八种梧桐属树种的影响及其潜在适生区变化、中国梧桐属多样性保护状态,可为中国梧桐属建立多样性保护廊道提供相关建议,为制定多样性保护规划及相应措施提供参考。 相似文献
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In fitting of cosine curves latent experimental inequalities due to a serial effect have to be excluded. Though cosinor analysis may be sufficient then, inclusion of biological time, i.e. not fitting values to time but to a function of time, will lead to further improvement. 相似文献
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The late Miocene North African mammalianassemblage is considered here from three viewpoints: survivals, extinctions, and immigrations. The Eurasiatic affinities of the large mammals slightly prevail over the Ethiopian affinities. Amongst the North African large mammals, 4 to 8 taxa are Eurasiatic immigrants, while 4 to 6 are of Subsaharian origin. Contrarily, the micromammalian fauna is highly endemic, with only one species, a murid (Paraethomys miocaenicus), considered here as being related to an Asiatic form (Karnimata darwini). Our study of Eurasian and African Miocene faunas reveals that during the late Astaracian-early Turolian interval, the Saharo-Arabic belt permitted very little latitudinal faunal exchanges. However, during the middle and late Turolian such faunal exchanges became frequent. The micromammal record unequivocally indicates that a brief period of faunal exchange occurred between Africa and western Europe at the end of the Miocene, corresponding with the Messinian Salinity Crisis. The increased intercontinental faunal exchange between Africa and Eurasia during the late Miocene coincides with, and counterbalances the extinction of more than 10 taxa at the Mio/Pliocene boundary. 相似文献
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Kazuyuki Yamamoto Yasufumi Iryu Shun Chiyonobu Eiichi Abe 《Palaeogeography, Palaeoclimatology, Palaeoecology》2006,241(1):160-175
We show responses of coral reefs to increased amplitude of sea-level changes at the Mid-Pleistocene Climate Transition (MPT) based on lithostratigraphic, sedimentologic and calcareous nannofossil biostratigraphic investigations on Pleistocene reef-complex deposits (Ryukyu Group) on the Motobu Peninsula, Okinawa-jima, Central Ryukyus. Our data show that reef growth started in earliest Quaternary time (1.45-1.65 Ma) and that extensive reef formation dates back to ∼ 0.8 Ma. The mode of Quaternary sedimentation changed at ∼ 0.8 Ma in the study area. Before this time, thick siliciclastics and mixed carbonate-siliciclastics accumulated, which were followed by the deposition of bioclastic sediments (detrital limestone). No indications have been found of episodic subaerial exposures in these deposits and no calcareous nannofossil biozones are lacking. Since the detrital limestone includes biogenic components characterizing fore-reef to shelf environments, the coastal areas of the northern Motobu Peninsula mostly lay in fore-reef to shelf environments for > 0.6 million years (between ∼ 0.8 Ma and 1.45-1.65 Ma), when the sediments had not been subaerially exposed due to sea-level changes characterized by relatively small amplitudes. Coral limestone that formed in the latest Early to Middle Pleistocene between 0.4 Ma and 0.8 Ma extends over the study area, ranging in elevation from 0 to 70 m. This coral limestone grades upward into fore-reef to shelf carbonates (rhodolith, Cycloclypeus-Operculina, and detrital limestones) which is in turn overlain by coral limestone. This succession, combined with configuration of the lithofacies and paleobathymetry inferred from lithology and biogenic components, implies that the reef-complex deposits formed responding to sea-level changes with amplitude of > 60 m. Consequently, we suggest that the change in the mode of sedimentation results from increased amplitude of sea-level fluctuations at ∼ 0.8 Ma. This timing corresponds roughly to the timing of the Mid-Pleistocene Climate Transition (MPT). 相似文献