Root exudates increase soil respiration and alter microbial community structure in alpine permafrost and active layer soils

Abstract

Due to climate warming, alpine ecosystems are changing rapidly. Ongoing upward migrations of plants and thus an increase of easily decomposable substrates will strongly affect the soil microbiome. To understand how belowground communities will respond to such changes, we set up an incubation experiment with permafrost and active soil layers from northern (NW) and southern (SE) slopes of a mountain ridge on Muot da Barba Peider in the Swiss Alps and incubated them with or without artificial root exudates (AREs) at two temperatures, 4 C or 15 C. The addition of AREs resulted in elevated respiration across all soil types. Bacterial and fungal alpha diversity decreased significantly, coinciding with strong shifts in microbial community structure in ARE-treated soils. These shifts in bacterial community structure were driven by an increased abundance of fast-growing copiotrophic taxa. Fungal communities were predominantly affected by AREs in SE active layer soils and shifted towards fastgrowing opportunistic yeast. In contrast, in the colder NW facing active layer and permafrost soils fungal communities were more influenced by temperature changes. These findings demonstrate the sensitivity of soil microbial communities in high alpine ecosystems to climate change and how shifts in these communities may lead to functional changes impacting biogeochemical processes.

Relationships between greenhouse gas production and landscape position during short-term permafrost thaw under anaerobic conditions in the Lena Delta

“…Solutions were injected via syringe to minimize soil disturbance (Pegoraro et al, 2019). The same amount of water as was added with the glucose solution was added to the third replicate to ensure that differences in gas production were only due to the addition of glucose (Pegoraro et al, 2019;Adamczyk et al, 2021). The glucose addition was also carried out under oxygen-free conditions.…”

Fungal communities in European alpine soils are not affected by short‐term in situ simulated warming than bacterial communities

“…According to predictive models, the rate of global warming is expected to be particularly accelerated in high mountain areas where an increase of the mean annual air temperature exceeding the global average (0.6 ± 0.2°C) was observed (Wieser, 2020). Climate change in the mountains leads to an alteration of the vegetation coverage of high elevation ecosystems; any plant modification can affect both the structure and the activity of beneath microbial communities, especially in soils perennially or temporarily exposed to cold (Adamczyk et al ., 2021; Pauli et al ., 2012; Steinbauer et al ., 2018; Yashiro et al ., 2016).…”

Screening and activity assessing of phosphorus availability improving microorganisms associated with bamboo rhizosphere in subtropical China

“…Local vegetation, in turn, may affect PSMicro growth and reproduction, not only indirectly by altering soil and microclimate conditions, but also directly by exchanging material with soil microbes (Costa et al ., 2006; Prashar et al ., 2014). Plants fix carbon through photosynthesis and can secrete carbon compounds into the root zone, which provide nutrients for root‐associated microbes and affect microbe community activities and microbial interspecies interactions in the rhizosphere (Adamczyk et al ., 2021). Root exudates from different plants can lead to different PSMicro communities (Marschner et al ., 2001; Paterson et al ., 2007).…”