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

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.

Direct and indirect effects of land-use intensity on plant communities across elevation in semi-natural grasslands

“…The positive effect of elevation on species number of rushes and sedges as observed in our study (S8 Table in S1 Appendix ) might be attributed to the increased humidity with increasing elevation [ 40 ], as rushes and sedges are known to dominate other species in increased soil moisture conditions [ 79 ]. Elevation was found to impact plant diversity and community composition in previous studies [ 45 , 80 , 81 ], mainly because of the correlation with climatic factors [ 45 , 81 – 83 ], for example due to higher rainfall at higher elevation [ 40 ]. Additionally, higher topographic variability with increasing elevation across our study area results in greater habitat diversity [ 42 ] and thus may allow plants to find suitable habitats within small distances, therefore potentially leading to higher species richness.…”

Mountains as a Global Heritage: Arguments for Conserving the Natural Diversity of Mountain Regions

“…The most notable properties of mountains that link abiotic and biotic diversity are their steep gradient and associated climatic variations, which effectively compress "life zones" and create a large number of local niches that support different biota [8]. Moreover, recent case studies have shed light on how geological properties, such as parent rock type and weathering pathways, explain local biodiversity in mountains [9]. In a recent paper, Rahbek et al (2019) visualized the evolution of mountain environments in the form of a schematic diagram that accounts for two major abiotic drivers-i.e., orogenic processes operating across deep geological time and climatic oscillations of glacials and interglacials spread over the Quaternary Period-that have left lasting imprints on the biotic environments of mountains [10] (Figure 1).…”

“…In a recent paper, Rahbek et al (2019) visualized the evolution of mountain environments in the form of a schematic diagram that accounts for two major abiotic drivers-i.e., orogenic processes operating across deep geological time and climatic oscillations of glacials and interglacials spread over the Quaternary Period-that have left lasting imprints on the biotic environments of mountains [10] (Figure 1). Together, the rich biodiversity and geodiversity of mountains make them important storehouses of natural diversity on the planet [9]. Therefore, mountains are not only important for their biodiversity, but are also irreplaceable for their abiotic features.…”

Plant Biodiversity of Monitoring Points V.AMANGELDY Almaty Region

“…Biodiversity is by no means the only, or even the primary, driver of ecosystem functions [4,5,13]. Both biodiversity and ecosystem functions have been known to be driven by common drivers of contemporary environments, such as climate and biotic and abiotic attributes [6][7][8][9]13].…”

“…Biodiversity is by no means the only, or even the primary, driver of ecosystem functions [4,5,13]. Both biodiversity and ecosystem functions have been known to be driven by common drivers of contemporary environments, such as climate and biotic and abiotic attributes [6][7][8][9]13]. Biodiversity could be also shaped by long-term drivers, such as geological processes, which impart lasting legacies on contemporary environments [10][11][12][13][14].…”