Belowground responses to elevation in a changing cloud forest

Abstract

Few studies have investigated how soil fungal communities respond to elevation, especially within TMCF (tropical montane cloud forests). We used an elevation gradient in a TMCF in Costa Rica to determine how soil properties, processes, and community composition of fungi change in response to elevation and across seasons. As elevation increased, soil temperature and soil pH decreased, while soil moisture and soil C:N ratios increased with elevation. Responses of these properties varied seasonally. Fungal abundance increased with elevation during wet and dry seasons. Fungal community composition shifted in response to elevation, and to a lesser extent by season. These shifts were accompanied by varying responses of important fungal functional groups during the wet season and the relative abundance of certain fungal phyla. We suggest that elevation and the responses of certain fungal functional groups may be structuring fungal communities along this elevation gradient. TMCF are ecosystems that are rapidly changing due to climate change. Our study suggests that these changes may affect how fungal communities are structured.

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

“…, Looby et al. , Geml ). For example, along other elevation gradients, the presence of EM and endophytic fungal hosts explained correlations in plant and fungal β‐diversity (Geml et al.…”

“…Fungal α‐diversity increased with a 4°C temperature increase across an elevation gradient in tropical montane cloud forest in Costa Rica, although decreased soil moisture also explained this diversity pattern (Looby et al. ). The majority of fungal diversity studies on mountain gradients have focused on specific phyla, reporting high variation in α‐diversity patterns (Geml et al.…”

Controls of nitrogen cycling evaluated along a well‐characterized climate gradient

“…Bryant et al (2008) found that Acidobacteria decreased in richness over a change of 1000 m elevation in the Rocky Mountains. Similarly mixed results have been found for Fungi, with evidence for greatest richness at mid-elevations due to range overlap (Bahram et al 2012, Coince et al 2014, Miyamoto et al 2014, lack of change with elevation (Zimmerman and Vitousek 2012, Coince et al 2014, Jarvis et al 2015, decreased richness at higher elevations (Looby et al 2016), or increased richness at higher elevations (Pellissier et al 2014). Fewer studies have examined Archaea, but work on two Japanese mountains found a mid-elevation peak in OTU richness (Singh et al 2012, Singh et al 2016).…”

“…For Fungi, previous studies have examined how the distribution and diversity at the level of all Fungi (Zhang et al 2013), at the functional group level (Bahram et al 2012) and at the phylum level (Looby et al 2016) change over an elevational gradient, and found that changes across the gradient became more apparent as lower taxonomic levels and/or ecological trait differences were accounted. We see similar patterns in our system, and changes in richness across this soil climosequence were clearly linked to resources for each group.…”

“…The consistent decrease in species richness with increasing altitude (Gaston 2000) along with parallel changes in climate (Korner 2000) suggest the existence of general principles controlling biodiversity. However, the studies that have examined microbial diversity along altitudinal gradients (Bryant et al 2008, Corneo et al 2013, Looby et al 2016, Wu et al 2017) have shown variable results. The lack of consistent microbial diversity patterns along climate gradients has suggested new and/or more inclusive hypotheses about the underlying drivers of biodiversity are necessary ).…”