Mountain biodiversity and ecosystem functions: interplay between geology and contemporary environments

Ang Hu,Minglei Ren,Yongping Yang,Hailiang Dong,Bin Niu,Guicai Si,Xinxin Zhu,Jian Wang,Xiancai Lu,Jianjun Wang,Jizhong Zhou,Chih-Fu Yeh,Hang Sun,Gengxin Zhang,Yilun Hu

doi:10.1038/s41396-019-0574-x

Abstract

Although biodiversity and ecosystem functions are strongly shaped by contemporary environments, such as climate and local biotic and abiotic attributes, relatively little is known about how they depend on long-term geological processes. Here, along a 3000-m elevational gradient with tectonic faults on the Tibetan Plateau (that is, Galongla Mountain in Medog County, China), we study the joint effects of geological and contemporary environments on biological communities, such as the diversity and community composition of plants and soil bacteria, and ecosystem functions. We find that these biological communities and ecosystem functions generally show consistent elevational breakpoints at 2000–2800 m, which coincide with Indus-Yalu suture zone fault and are similar to the elevational breakpoints of soil bacteria on another mountain range 1000 km away. Mean annual temperature, soil pH and moisture are the primary contemporary determinants of biodiversity and ecosystem functions, which support previous findings. However, compared with the models excluding geological processes, inclusion of geological effects, such as parent rock and weathering, increases 67.9 and 35.9% of the explained variations in plant and bacterial communities, respectively. Such inclusion increases 27.6% of the explained variations in ecosystem functions. The geological processes thus provide additional links to ecosystem properties, which are prominent but show divergent effects on biodiversity and ecosystem functions: parent rock and weathering exert considerable direct effects on biodiversity, whereas indirectly influence ecosystem functions via interactions with biodiversity and contemporary environments. Thus, the integration of geological processes with environmental gradients could enhance our understanding of biodiversity and, ultimately, ecosystem functioning across different climatic zones.

Highlights

It has long been the core of ecology for disentangling the mechanisms underlying temporospatial distributions of biodiversity, and further ecosystem functions [1,2,3,4]
We addressed the question of how biodiversity and ecosystem functions vary along an elevational gradient, what are the main drivers for such elevational patterns, and how geological processes directly and indirectly affect biodiversity and ecosystem functions
Along an elevational gradient of 700–3760 m on Galongla Mountain on the South-East Tibetan Plateau, we examined the biological communities and ecosystem functions for 180 plots at 18 sites covering multiple climatic and vegetation zonations from tropical monsoon rainforests to frigid shrub meadows (Fig. 1b, c)

Summary

1234567890();,: 1234567890();,: Introduction

It has long been the core of ecology for disentangling the mechanisms underlying temporospatial distributions of biodiversity, and further ecosystem functions [1,2,3,4]. Along an elevational gradient of 700–3760 m on Galongla Mountain on the South-East Tibetan Plateau, we examined the biological communities and ecosystem functions for 180 plots at 18 sites covering multiple climatic and vegetation zonations from tropical monsoon rainforests to frigid shrub meadows (Fig. 1b, c). We further expected the long-term processes (that is, parent rock and weathering) would directly mediate the biodiversity and ecosystem functioning, and show indirect influences via the interaction with contemporary environments.

Materials and methods

Results and discussion

Compliance with ethical standards