Liverworts show a globally consistent mid‐elevation richness peak

Ecology and Evolution, vol. 13, pp. e9862

Abstract

The study of elevational gradients allows to draw conclusions on the factors and mechanisms determining patterns in species richness distribution. Several earlier studies investigated liverwort diversity on single or few elevational transects. However, a comprehensive survey of the elevational distribution patterns of liverwort richness and their underlying factors is lacking so far. This study's purpose was to fill this gap by compiling an extensive data set of liverwort elevational patterns encompassing a broad diversity of mountains and mountain ranges around the world. Using polynomial regression analyses, we found a prevalence of hump-shaped richness patterns (19 of 25 gradients), where liverwort species richness peaked at mid-elevation and decreased towards both ends of the gradient. Against our expectation and unlike in other plant groups, in liverworts, this pattern also applies to elevational gradients at mid-latitudes in temperate climates. Indeed, relative elevation, calculated as the percentage of the elevational range potentially inhabited by liverworts, was the most powerful predictor for the distribution of liverwort species richness. We conclude from these results that the admixture of low- and high-elevation liverwort floras, in combination with steep ecological gradients, leads to a mid-elevation floristic turnover shaping elevational patterns of liverwort diversity. Our analyses further detected significant effects of climatic variables (temperature of the warmest month, potential evapotranspiration, and precipitation of the warmest month) in explaining elevational liverwort richness patterns. This indicates that montane liverwort diversity is restricted by high temperatures and subsequent low water availability especially towards lower elevations, which presumably will lead to serious effects by temperature shifts associated with global warming.

Authors 7

1. Karola Maul corresponding

   University of Bonn

   Affiliation as printed

   Nees Institute for Biodiversity of Plants University of Bonn Bonn Germany

   Nees Institute for Biodiversity of Plants, University of Bonn, Bonn, Germany

2. Yu‐Mei Wei

   Chinese Academy of Sciences · Guangxi Institute of Botany

   Affiliation as printed

   Guangxi Key Laboratory of Plant Conservation and Restoration Ecology in Karst Terrain, Guangxi Institute of Botany Guangxi Zhuang Autonomous Region and Chinese Academy of Sciences Guilin China

   Guangxi Key Laboratory of Plant Conservation and Restoration Ecology in Karst Terrain, Guangxi Institute of Botany, Guangxi Zhuang Autonomous Region and Chinese Academy of Sciences, Guilin, China

3. Eka Aditya Putri Iskandar Aachen Institute of Biology Leiden Faculty of Science Leiden University Leiden The Netherlands Understanding Evolution Research Group Naturalis Biodiversity Center Leiden The Netherlands Faculty of Science, Leiden University Understanding Evolution Research Group Naturalis Biodiversity Center

   Leiden University · Naturalis Biodiversity Center · National Research and Innovation Agency

   Affiliation as printed

   Cibodas Botanic Garden National Research and Innovation Agency (BRIN) Bandung Indonesia

   Institute of Biology Leiden, Faculty of Science Leiden University Leiden The Netherlands

   Understanding Evolution Research Group Naturalis Biodiversity Centre Leiden The Netherlands

   Cibodas Botanic Garden, National Research and Innovation Agency (BRIN), Bandung, Indonesia

   Institute of Biology Leiden, Faculty of Science, Leiden University, Leiden, The Netherlands

   Understanding Evolution Research Group, Naturalis Biodiversity Centre, Leiden, The Netherlands

4. Sahut Chantanaorrapint

   Prince of Songkla University

   Affiliation as printed

   Division of Biological Sciences, Faculty of Science Prince of Songkla University Hat Yai Thailand

   Division of Biological Sciences, Faculty of Science, Prince of Songkla University, Hat Yai, Thailand

5. Boon‐Chuan Ho

   National Parks Board

   Affiliation as printed

   Singapore Botanic Gardens National Parks Board Singapore Republic of Singapore

   Singapore Botanic Gardens, National Parks Board, Singapore, Republic of Singapore

6. Dietmar Quandt

   University of Bonn

   Affiliation as printed

   Nees Institute for Biodiversity of Plants University of Bonn Bonn Germany

   Nees Institute for Biodiversity of Plants, University of Bonn, Bonn, Germany

7. Michael Kessler

   University of Zurich

   Affiliation as printed

   Systematic and Evolutionary Botany University of Zurich Zurich Switzerland

   Systematic and Evolutionary Botany, University of Zurich, Zurich, Switzerland