Synergic hydraulic and nutritional feedback mechanisms control surface patchiness of biological soil crusts on tertiary sands at a post-mining site

Abstract

Abstract:In a recultivation area located in Brandenburg, Germany, five types of biocrusts (initial BSC1, developed BSC2 and BSC3, mosses, lichens) and non-crusted mineral substrate were sampled on tertiary sand deposited in [1985][1986] to investigate hydrologic interactions between crust patches. Crust biomass was lowest in the non-crusted substrate, increased to the initial BSC1 and peaked in the developed BSC2, BSC3, the lichens and the mosses. Water infiltration was highest on the substrate, and decreased to BSC2, BSC1 and BSC3. Non-metric multidimensional scaling revealed that the lichens and BSC3 were associated with water soluble nutrients and with pyrite weathering products, thus representing a high nutrient low hydraulic feedback mode. The mosses and BSC2 represented a low nutrient high hydraulic feedback mode. These feedback mechanisms were considered as synergic, consisting of run-off generating (low hydraulic) and run-on receiving (high hydraulic) BSC patches. Three scenarios for BSC succession were proposed.(1) Initial BSCs sealed the surface until they reached a successional stage (represented by BSC1) from which the development into either of the feedback modes was triggered, (2) initial heterogeneities of the mineral substrate controlled the development of the feedback mode, and (3) complex interactions between lichens and mosses occurred at later stages of system development.

Biocrust landscape‐scale spatial distribution is strongly controlled by terrain attributes: Topographic thresholds for colonization in a semiarid badland system

“…Though this is not a universal model for dryland soil succession and surface component distribution generalizable to all areas, similar patterns have been observed in other regions with different climate conditions and soil properties (Kidron et al, 2010;Fischer et al, 2014;Durham et al, 2018). For example, Kidron et al (2010) found that in undisturbed areas in the Negev, cyanobacteria-dominated biocrusts predominated on the sunniest hillslopes, whereas lichen and mosses were more frequent in shaded areas with longer wet periods.…”

“…These specific adaptations facilitate their survival, even under very dry conditions, as observed in many other places (Kidron et al, 2010;Dojani et al, 2011;Patzelt et al, 2014). Other studies in more mesic environments have found that higher cyanobacterial concentrations in depositional areas are related to the strong resilience of these organisms to salinity stress, as water and salt redistribution by runoff from hillslopes to these areas tend to concentrate salts on the surface (Fischer et al, 2014). Other studies in more mesic environments have found that higher cyanobacterial concentrations in depositional areas are related to the strong resilience of these organisms to salinity stress, as water and salt redistribution by runoff from hillslopes to these areas tend to concentrate salts on the surface (Fischer et al, 2014).…”

“…Hence, when soil is stable enough for cyanobacterial colonization (below 9.7 LSF; Figure 3), cyanobacteria-dominated biocrusts become the dominant surface component in flat areas (Figure 5), which are the sunniest landforms ( Figure 2). Other studies in more mesic environments have found that higher cyanobacterial concentrations in depositional areas are related to the strong resilience of these organisms to salinity stress, as water and salt redistribution by runoff from hillslopes to these areas tend to concentrate salts on the surface (Fischer et al, 2014). At El Cautivo, both the spatial distribution and topographic position of soil units favour gypsum and salt leaching on well-developed, permeable soils within the pediments (Table S1).…”

Biocrust research: A critical view on eight common hydrological‐related paradigms and dubious theses

“…This is the principal rationale for the Hortonian flow that takes place in arid and semiarid regions (Horton, ). Pore clogging was also shown to determine run‐off from biocrusts (Fischer, Gypser, Subotina, & Veste, ; Fischer, Veste, Wiehe, & Lange, ; Kidron et al, ; Verrecchia, Yair, Kidron, & Verrecchia, ). The notion that soil pores, that is, subsurface pores (especially macro pores) determine infiltration on biocrusted surfaces, is however highly questionable.…”

Microbial Biobanking Cyanobacteria-rich topsoil facilitates mine rehabilitation

“…Research into biocrust disturbance and recovery post-mining is rare (see Fischer et al, 2014;Lukešová, 2001;Mazor et al, 1996;Setyawan et al, 2016), yet there is a real need for focus on practical approaches that contribute to the restoration of soil 10 function and measure relevant aspects of success through soil microbial communities (Harris, 2003;Tongway and Hindley, 2004). Mine rehabilitation is a complex process that involves many levels of understanding of difficult issues relating to ecosystem function where the removal or burial of the bioactive soils can have knock-on effects for rehabilitation efforts such as native seedling establishment.…”