Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo, Japan.
University and Jepson Herbaria, and Department of Integrative Biology, University of California, Berkeley, CA, USA.
Am J Bot. 2022 May;109(5):727-745. doi: 10.1002/ajb2.1848. Epub 2022 May 19.
Biodiversity is often only measured with species richness; however, this metric ignores evolutionary history and is not sufficient for making conservation decisions. Here, we characterize multiple facets and drivers of biodiversity to understand how these relate to bioregions and conservation status in the ferns of Japan.
We compiled a community data set of 1239 grid cells (20 × 20 km each) including 672 taxa based on >300,000 specimen records. We combined the community data with a phylogeny and functional traits to analyze taxonomic, phylogenetic, and functional diversity and modeled biodiversity metrics in response to environmental factors and reproductive mode. Hierarchical clustering was used to delimit bioregions. Conservation status and threats were assessed by comparing the overlap of significantly diverse grid cells with conservation zones and range maps of native Japanese deer.
Taxonomic richness was highest at mid-latitudes. Phylogenetic and functional diversity and phylogenetic endemism were highest in small southern islands. Relative phylogenetic and functional diversity were high at high and low latitudes, and low at mid-latitudes. Grid cells were grouped into three (phylogenetic) or four (taxonomic) major bioregions. Temperature and apomixis were identified as drivers of biodiversity patterns. Conservation status was generally high for grid cells with significantly high biodiversity, but the threat due to herbivory by deer was greater for taxonomic richness than other metrics.
Our integrative approach reveals previously undetected patterns and drivers of biodiversity in the ferns of Japan. Future conservation efforts should recognize that threats can vary by biodiversity metric and consider multiple metrics when establishing conservation priorities.
生物多样性通常仅通过物种丰富度来衡量；然而，这种度量标准忽略了进化历史，对于做出保护决策是不够的。在这里，我们描述了生物多样性的多个方面和驱动因素，以了解这些因素与日本蕨类植物的生物区系和保护状况之间的关系。
我们根据超过 300,000 个标本记录，编制了一个包含 1239 个网格单元（每个 20×20 公里）的群落数据集，其中包含 672 个分类群。我们将群落数据与系统发育和功能特征相结合，分析分类学、系统发育和功能多样性，并根据环境因素和繁殖方式对生物多样性指标进行建模。使用层次聚类来划定生物区系。通过比较具有显著多样性的网格单元与保护区和本地日本鹿的分布范围的重叠情况来评估保护状况和威胁。
分类学丰富度在中纬度地区最高。小南部岛屿的系统发育和功能多样性以及系统发育特有性最高。相对系统发育和功能多样性在高纬度和低纬度较高，而在中纬度较低。网格单元被分为三个（系统发育）或四个（分类学）主要生物区系。温度和无融合生殖被确定为生物多样性模式的驱动因素。对于具有显著高生物多样性的网格单元，保护状况通常较高，但由于鹿的食草性造成的威胁对于分类学丰富度而言比其他指标更大。
我们的综合方法揭示了日本蕨类植物生物多样性的先前未被发现的模式和驱动因素。未来的保护工作应该认识到，威胁可能因生物多样性指标而异，并在确定保护优先事项时考虑多个指标。
