Snow vole (Chionomys nivalisMartins) affects the redistribution of soil organic matter and hormone‐like activity in the alpine ecosystem: ecological implications

Abstract

In alpine environments, colonies of snow vole (Chionomys nivalis Martins) cause strong pedoturbation, which may affect humification process and soil organic matter (SOM) cycling, with repercussions on the hormone‐like activity of organics. We investigated the effect of snow vole pedoturbation on the chemical and spectroscopic features of soil organic fractions, and the potential hormone‐like activity of humic and fulvic acids (HA, FA). The study site was located on the high‐mountain environment of the Majella massif (central Italy). Pedoturbated and regular soils were morphologically described and characterized for pH and content of total organic carbon, total extractable carbon, HA, and FA. Both HA and FA were extracted and investigated using attenuated total reflectance/Fourier transform infrared (ATR/FTIR), nuclear magnetic resonance with high‐resolution magic angle spinning (HRMAS‐NMR), and 1H‐13C heteronuclear single quantum coherence (HSQC). HA and FA were also tested for their auxin‐like and gibberellin‐like activities. Results provide evidences that bioturbated and regular soils contain a poorly decomposed SOM, but HA and FA with a well‐defined molecular structure. The HA and FA from both bioturbated and regular soils show a hormone‐like activity with a different allocation along the soil profile. In the regular soil, the highest auxin‐like activity was shown by HA and FA from Oe1 horizon, while gibberellin‐like activity was expressed by FA from Oe2 horizon. Burrowing activity determines a redistribution of organics throughout the profile with a relatively high auxin‐like activity in the FA from straw tunnel wall (STW) and gibberellin‐like activity in the HA from vole feces (VF). The relative high presence of carboxylic acids, amides, proteins, and amino acids in the FA from STW and the aromatic moieties in the HA from VF put evidences for their different behavior. The fact that snow vole activity has modified the chemical and biological properties of SOM in these soils otherwise considered governed only by low temperature has important ecological implications such as the preservation of soil fertility and vegetal biodiversity.

Effects of farmed managements in sandy soils on composition and stabilization of soil humic substances

“…The separation of the three sandy-textured soils and the G, R, and AFS management systems from the Organosol under monoculture (M) management confirms that the mineral fraction directly affects the structural and compositional quality of HA (horizontal grouping in Figure 6). The effects of HS on soil fertility and characteristics have been extensively reported in the literature (Kögel-Knabner, de Leeuw, & Hatcher, 1992;Mamedov et al, 2016;Piccolo, Conte, & Cozzolino, 1999;Pizzeghello et al, 2015;Senesi & Plaza, 2007;Tan, 2014). However, this study distinguishes the types of HA structures with the strongest relationships with the chemical or physical attributes ( Figure 6).…”

Chemical and Biochemical Properties of Soils Developed from Different Lithologies in Northwestern Spain (Galicia)

“…In fact, both HA and FA of all the soils showed a hormone-like activity that might contribute to regulate the growth of the root main axes and their density, and the surface absorbing area. In this way, the plants would be able to uptake a higher amount of nutrients because of the stimulation offered by the humic substances formed in the soil [21,22]. The HA extracted from the soil derived from serpentinite displayed the greatest auxin-like activity.…”

“…Among the strategies adopted, symbiosis with arbuscular mycorrhizal fungi allow vegetation to increment its edaphic tolerance (e.g., [19]). Among the soil-plant relationships that are functional in terms of improving plant resilience and, consequently, biomass production and soil carbon sequestration, the hormone-like activity of the humic substances seems to have an important role [20][21][22]. Humic substances exert a hormone-like activity due to the presence of indole-3-acetic acid (IAA), a plant hormone of the auxin class [23,24].…”

EurJOC around the Clock

“…A recent study conducted in alpine environments found that colonies of snow vole ( Chionomys nivalis Martins) caused a strong modification of the organic matter turnover, which determined the prevalence of the humification process. The HS arising from this soil organic matter cycling exhibited a high auxin‐like activity ( Pizzeghello et al, 2015).…”