Microbes follow Humboldt: temperature drives plant and soil microbial diversity patterns from the Amazon to the Andes

Abstract

SummaryMore than 200 years ago, von Humboldt reported decreases in tropical plant species richness with increasing elevation and decreasing temperature. Surprisingly, co-ordinated patterns in plant, bacterial and fungal diversity on tropical mountains are yet to be observed, despite the central role of soil microorganisms in terrestrial biogeochemistry. We studied an Andean transect traversing 3.5 km in elevation to test whether the species diversity and composition of tropical forest plants, soil bacteria and fungi can follow similar biogeographical patterns with shared environmental drivers. We found co-ordinated changes with elevation in all three groups: species richness declined as elevation increased, and the compositional-dissimilarity of communities increased with increased separation in elevation, although changes in plant diversity were larger than in bacteria and fungi. Temperature was the dominant driver of these diversity gradients, with weak influences of edaphic properties, including soil pH. The gradients in microbial diversity were strongly correlated with the activities of enzymes involved in organic matter cycling, and were accompanied by a transition in microbial traits towards slower-growing, oligotrophic taxa at higher elevations. We provide the first evidence of co-ordinated temperature-driven patterns in the diversity and distribution of three major biotic groups in tropical ecosystems: soil bacteria, fungi and plants. These findings suggest that, across landscape scales of relatively constant soil pH, inter-related patterns of plant and microbial communities with shared environmental drivers can occur, with large implications for tropical forest communities under future climate change.

Metagenomic analysis reveals the shared and distinct features of the soil resistome across tundra, temperate prairie and tropical ecosystems

“…This is consistent to previous studies which also found strong correlation between ARG pro le and bacterial community structure in various environmental contexts [56][57][58]. Thus, the variation of soil resistomes at different geographical locations was probably related to the differing plant diversity, climate, and edaphic factors such as pH and soil organic matter [59][60][61] which will select different populations (and hence the ARGs they carry) or some ARGs by their alternative function.…”

Community assemblage of free-living diazotrophs along the elevational gradient of Mount Gongga

“…Climate may be a potential force to shape diversity patterns of both plants and diazotrophs. Nottingham et al (2018) report that temperature plays a fundamental role in driving the coordinated patterns of plant and soil microbial diversity, based on their survey from the Amazon rainforest to the Andes Mountains. Furthermore, soil pH, conductivity, NH 4 + -N, NO 3…”

Variation in Soil Microbial Communities Along an Elevational Gradient in Alpine Meadows of the Qilian Mountains, China

“…However, the relative importance of regional climate conditions and local soil conditions on the soil microbial community's elevational distribution patterns remains controversial. Some authors suggest that temperature strongly affects soil microbial diversity and community composition along an elevational gradients (Singh et al, 2014;Nottingham et al, 2018), whereas others suggest that soil pH is the most important driver of the elevational distribution (Shen et al, 2013(Shen et al, , 2019Wang et al, 2015;Peay et al, 2017). These differences can likely be attributed to differences between ecosystem types, elevations, research scales, microbial groups included in the study, and research techniques.…”