Institute of Marine Science, The University of Auckland, Auckland 1142, New Zealand;
School of Biological Sciences, The University of Hong Kong, Pokfulam, Hong Kong 999077.
Proc Natl Acad Sci U S A. 2021 Apr 13;118(15). doi: 10.1073/pnas.2015094118.
The latitudinal gradient in species richness, with more species in the tropics and richness declining with latitude, is widely known and has been assumed to be stable over recent centuries. We analyzed data on 48,661 marine animal species since 1955, accounting for sampling variation, to assess whether the global latitudinal gradient in species richness is being impacted by climate change. We confirm recent studies that show a slight dip in species richness at the equator. Moreover, richness across latitudinal bands was sensitive to temperature, reaching a plateau or declining above a mean annual sea surface temperature of 20 °C for most taxa. In response, since the 1970s, species richness has declined at the equator relative to an increase at midlatitudes and has shifted north in the northern hemisphere, particularly among pelagic species. This pattern is consistent with the hypothesis that climate change is impacting the latitudinal gradient in marine biodiversity at a global scale. The intensification of the dip in species richness at the equator, especially for pelagic species, suggests that it is already too warm there for some species to survive.
物种丰富度的纬度梯度，即热带地区物种较多，而随着纬度的增加，物种丰富度逐渐减少，这是广为人知的，并被认为在最近几个世纪以来是稳定的。我们分析了自 1955 年以来的 48661 种海洋动物物种的数据，考虑了采样的变化，以评估全球物种丰富度的纬度梯度是否受到气候变化的影响。我们证实了最近的研究表明，在赤道地区物种丰富度略有下降。此外，大多数分类群的纬度带丰富度对温度敏感，在年平均海面温度超过 20°C 时达到一个平台或下降。因此，自 20 世纪 70 年代以来，与中纬度地区的增加相比，赤道地区的物种丰富度下降了，并且在北半球向北转移，特别是在远洋物种中。这种模式与气候变化正在全球范围内影响海洋生物多样性的纬度梯度的假设是一致的。赤道地区物种丰富度下降幅度的加剧，尤其是对远洋物种而言，表明那里的温度已经对某些物种的生存造成了威胁。
