Ectomycorrhizal fungal communities in ice-age relict forests of Pinus pumila on nine mountains correspond to summer temperature

Abstract

Ectomycorrhizal (ECM) fungi are critical symbionts of major forest trees, and their communities are affected by various environmental factors including temperature. However, previous knowledge concerning temperature effects does not exclude the effects of host species and coexisting plants, which usually change with temperature, and should be rigorously tested under the same vegetation type. Herein we examined ECM fungal communities in ice-age relict forests dominated by a single host species (Pinus pumila) distributed on nine mountains across >1000 km in Japan. Direct sequencing of rDNA ITS regions identified 154 ECM fungal species from 4134 ECM root-tip samples. Gradient analyses revealed a large contribution of temperature, especially summer temperature, to ECM fungal communities. Additionally, we explored global sequence records of each fungal species to infer its potential temperature niche, and used it to estimate the temperature of the observed communities. The estimated temperature was significantly correlated with the actual temperature of the research sites, especially in summer seasons, indicating inherent temperature niches of the fungal components could determine their distribution among the sites. These results indicate that temperature is still a significant determinant in structuring ECM fungal communities after excluding the effects of host species and coexisting plants. The results also imply that the rising temperature under global warming may have been affecting soil microbes unnoticeably, while such microbial community change may have been contributing to the resilience of the same vegetation.

Habitat specialisation controls ectomycorrhizal fungi above the treeline in the European Alps

“…In our extensive study, we found that mostly /cortinarius OTUs were influenced by environmental factors, more frequently found in alpine sites, and in particular in the snowbed habitats than in sites closer to the treeline. Similar results were found by Yao et al (2013) and by Koizumi & Nara (2020) highlighting a temperature dependency of Cortinarius at the treeline, with more frequent records at lower mean summer temperatures.…”

Elevation Matters More than Season in Shaping the Heterogeneity of Soil and Root Associated Ectomycorrhizal Fungal Community

“…Elevation characteristics are usually characterized by specific temperature and slow-changing soil properties, such as soil pH and total soil nutrients—organic carbon, N, P, and K are stable with respect to time and take centuries or millions of years to change ( 41 ). Temperature is a key driver that shapes the EcM fungal assemblages at the regional scale ( 4 , 69 ), whereas slow-changing soil properties show an explanatory power on spatial dynamics of soil bacterial and fungal communities ( 41 ). However, only a small portion of the variations in the EcM fungal community along the altitudinal gradient could be explained by these variables (Fig.…”

Fungal Diversity and Community Assembly of Ectomycorrhizal Fungi Associated With Five Pine Species in Inner Mongolia, China

“…It has been well established that common fungal taxa grow well in proper habitats in soil nutrients, water content, and temperature ( Cox et al, 2010 ; Miyamoto et al, 2018 ; Guo et al, 2020 ). For example, the frequency of some fungal taxa decreased with an increase in temperature, whereas some exhibited an opposite trend ( Miyamoto et al, 2018 ; Koizumi and Nara, 2019 ); similarly, the population of some fungal taxa increased by additional nutrient inputs, whereas some were inhibited ( Corrales et al, 2017 ). These findings suggested that different fungal taxa commonly occupied distinct niche positions.…”