Department of Ecology and Evolutionary Biology, University of Arizona, Tucson, Arizona, USA.
Departamento de Ecología, Pontificia Universidad Católica de Chile, Santiago, Chile.
Ecol Lett. 2022 Jun;25(6):1376-1386. doi: 10.1111/ele.13999. Epub 2022 Mar 25.
Many biodiversity studies focus on explaining high tropical species richness, but an equally dramatic yet understudied pattern involves the divergent richness of land, sea and freshwater. Here, we reveal the origins of these richness differences among habitats across animals and plants. Most plant and animal species are terrestrial, although these habitats cover only 28% of Earth's surface. Marine habitats have fewer species over a larger area (70%). Freshwater habitats have relatively high richness and exceptional phylogenetic diversity given their tiny area (2%). The relative richness of habitats is related to variation in diversification rates. Based on ancestral reconstructions of habitat, we find that most marine species are descended from marine ancestors and most terrestrial species from freshwater ancestors. Yet, most extant animal richness in freshwater is derived from terrestrial ancestors. Overall, our results reveal the origins of fundamental but neglected biodiversity patterns, and highlight the conservation importance of freshwater habitats.
许多生物多样性研究都致力于解释热带地区物种丰富度高的原因，但同样引人注目却研究不足的模式涉及陆地、海洋和淡水生物多样性的差异。在这里，我们揭示了这些栖息地之间动物和植物丰富度差异的起源。尽管这些栖息地仅占地球表面的~28%，但大多数植物和动物物种都是陆生的。海洋栖息地的物种较少，但面积较大（约 70%）。与它们的微小面积相比（2%），淡水栖息地的物种相对丰富，且具有特殊的系统发育多样性。栖息地的相对丰富度与多样化率的变化有关。基于对栖息地祖先的重建，我们发现大多数海洋物种来自海洋祖先，而大多数陆地物种来自淡水祖先。然而，大多数现存的淡水动物丰富度都来自陆地祖先。总的来说，我们的研究结果揭示了基本但被忽视的生物多样性模式的起源，并强调了淡水栖息地的保护重要性。
