Small-scale variability of soil properties and soil–vegetation relationships in patterned ground on different lithologies (NW Italian Alps)

Abstract

Cryogenic patterned ground represents spectacular periglacial landscapes. On the Alps, sorted/nonsorted patterned ground features larger than 1 m, formed by deep seasonal cryoturbation with or without permafrost, occupy exposed, stable surfaces at high altitudes and represent a particularly harsh habitat for plant life. We analyzed soils across transects through typical active patterned ground features (sorted/nonsorted circles and stripes) on four common lithotypes (calcschists, serpentinite, gabbros and gneiss) in the Western Italian Alps, in order to observe the small-scale lateral and depth variability in physico-chemical properties, and their association with cryoturbation, plant cover and species distribution. Cryoturbation was correlated with lateral/vertical textural sorting across features, mostly visible on silt and coarse sand, but with opposite trends on sorted and nonsorted patterned ground types. A strong lateral variability in organic carbon was detected, with high values near the better vegetated rims and low contents in the centers. Exchangeable bases, heavy metals and nutrients followed the same distribution. However, the differences inherited from the parent materials were overwhelming. Climate is the main driver of high altitude ecosystems, reducing total plant cover and causing cryoturbation, which in turn creates strong edaphic gradients over small distances. Plant species and communities are well correlated with edaphic properties inherited from the parent materials, such as exchangeable Ca and heavy metals.

Soil types of Aosta Valley (NW-Italy)

“…In particular, 333 soil profiles were obtained from several collaborations between Aosta Valley Region and the DISAFA -University of Turin, Italy, which resulted in many publications (i.e. Curtaz et al, 2015;D'Amico, Bonifacio et al, 2014;D'Amico, Freppaz et al, 2014;D'Amico, Gorra et al, 2015;Pintaldi et al, 2016Pintaldi et al, , 2018Pintaldi et al, , 2019Scalenghe et al, 2002;Stanchi et al, 2012Stanchi et al, , 2013Stanchi et al, , 2015 or from master theses under the supervision of DISAFA faculty members; 24 profiles were obtained from an ongoing project between the University of Milano Bicocca and Gran Paradiso National Park (dr. C. Canedoli and R. Comolli, unpublished); 18 profiles in vineyards were obtained from Minelli (2008, available at Institute Agricole Regional, unpublished); 41 were opened in 1995-1997 by IPLA (Istituto per le Piante da Legno e l'Ambiente, unpublished); 130 derived from D'Amico et al 2008and D'Amico and Previtali (2012), located in Mont Avic Natural Park; 18 were produced in 2004 by Michele D'Amico for ARPA VDA (unpublished data) in the area between Pontey and Chambave. After collecting all the available soil data, during summer 2018, 138 additional profiles were opened to get further information in understudied areas of the region.…”

Dynamics of soil organic carbon and nitrogen following agricultural abandonment in a karst region

“…Lithology regulates many processes at the Earth's surface including the fluxes of matter to soils [ Hartmann and Moosdorf , ]. Due to its important role in determining soil physicochemical properties, lithology has been documented to exert substantial influences on the composition and function of plant and microbial communities [ D'Amico et al , ; Reith et al , ]. Since soil properties, plant, and microbial communities all contribute to soil C dynamics, it is reasonable to hypothesize that lithology also poses a great influence on soil C content and its dynamics following land use change.…”

“…Considering the crucial role of soil C dynamics in global C cycling and, subsequently, the climate change [Lal, 2004], it is undoubtedly imperative to unravel the mechanisms underlying the direction and magnitude of soil C dynamics following agricultural abandonment. on the composition and function of plant and microbial communities [D'Amico et al, 2015;Reith et al, 2012]. Since soil properties, plant, and microbial communities all contribute to soil C dynamics, it is reasonable to hypothesize that lithology also poses a great influence on soil C content and its dynamics following land use change.…”

Successional Herbaceous Species Affect Soil Processes in a High-Elevation Alpine Proglacial Chronosequence

“…Nonetheless, unlike processes involving organic matter, TN resulted in very low concentrations even in the oldest stages, representing the major limiting factor for more nutrient-demanding plant species. Where measurable, the TOC:TN ratio was between 8 and 17.5, thus in the normal range for high-altitude grassland and tundra soils (e.g., D'Amico et al, 2014D'Amico et al, , 2015. The increase in both microbial C and N associated to the target species (and more generally to vascular species cover) along the chronosequence proved again the strong biotic impact in nutrient accumulation compared to abiotic processes, such as atmospheric deposition.…”