Water’s path from moss to soil: A multi-methodological study on water absorption and evaporation of soil-moss combinations

Abstract

Mosses are often overlooked; however, they are important for soil-atmosphere interfaces with regard to water exchange. This study investigated the influence of moss structural traits on maximum water storage capacities (WSCmax) and evaporation rates, and species-specific effects on water absorption and evaporation patterns in moss layers, moss-soil-interfaces and soil substrates using biocrust wetness probes. Five moss species typical for Central European temperate forests were selected: field-collected Brachythecium rutabulum, Eurhynchium striatum, Oxyrrhynchium hians and Plagiomnium undulatum; and laboratory-cultivated Amblystegium serpens and Oxyrrhynchium hians. WSCmax ranged from 14.10 g g−1 for Amblystegium serpens (Lab) to 7.31 g g−1 for Plagiomnium undulatum when immersed in water, and 11.04 g g−1 for Oxyrrhynchium hians (Lab) to 7.90 g g−1 for Oxyrrhynchium hians when sprayed, due to different morphologies depending on the growing location. Structural traits such as high leaf frequencies and small leaf areas increased WSCmax. In terms of evaporation, leaf frequency displayed a positive correlation with evaporation, while leaf area index showed a negative correlation. Moisture alterations during watering and desiccation were largely controlled by species/substrate-specific patterns. Generally, moss cover prevented desiccation of soil surfaces and was not a barrier to infiltration. To understand water’s path from moss to soil, this study made a first contribution.

Pioneer biocrust communities prevent soil erosion in temperate forests after disturbances

“…Bryophyte covers in temperate forest are known to stabilize soil surfaces and, thus, act as a protective agent against soil erosion (Mägdefrau and Wutz, 1951;Belnap and Büdel, 2016;Seitz et al, 2017). The same applies to covers of vascular plants (Zuazo Durán and Rodríguez Pleguezuelo, 2009); however, it is assumed that bryophyte communities have a stronger erosion-reducing effect than vascular plants (Casermeiro et al, 2004;Bu et al, 2015) due to their large water absorption capacity (Thielen et al, 2021) and the soilstabilizing effect of their rhizoids (Mitchell et al, 2016). In this context, the biocrust characteristics were demonstrated in this study at the initial successional stage, with communities of bryophytes, their protonemata, cyanobacteria, and algae, for example, seeming to further enhance the erosionreducing effect.…”

“…These mechanisms of water storage capacity are influenced by the complex 3D structure of bryophytes; the composition of a variety of individual functional traits, e.g. leaf area, leaf frequency, leaf area per shoot length, leaf area index, total surface area, shoot length, and shoot density; and their ability to form dense colony-level cushions (Elumeeva et al, 2011;Glime, 2021;Thielen et al, 2021). As most studies investigating the impact of biocrusts on soil erosion have been conducted in arid and semiarid regions, their influence in humid and temperate climates is largely unknown (Weber et al, 2016;Eldridge et al, 2020).…”

Pioneer biocrust communities prevent soil erosion in temperate forests after disturbances

“…Contrary results were reported by Parsakhoo et al (2012) who found that bryophyte-covered ROPs produced more sediment compared to ROPs with Rubus hyrcanus. However, it is still not clear which traits influence the stabilizing effect of biocrusts and likewise there are still a number of unresolved questions regarding the bryophyte-soil interactions in water absorption and erosion processes (Thielen et al, 2021).…”

“…These mechanisms of water storage capacity are influenced by the complex 3D structure of bryophytes, composed of a variety of individual functional traits (e.g. leaf area, leaf frequency, leaf area per shoot length, leaf area index, total surface area, shoot length, shoot density), and their ability to form dense colony-level cushions (Thielen et al, 2021;Glime, 2017;Elumeeva et al, 2011). As the very most studies on the impact of biocrusts on soil erosion have been conducted in arid and semi-arid regions, their influence in humid climates is widely unknown Eldridge et al, 2020).…”

Biocrust-linked changes in soil aggregate stability along a climatic gradient in the Chilean Coastal Range

“…Despite their simple structure, biocrusts are present in a wide variety of climatic conditions. Biocrust organisms 45 lack specialized desiccation control structures, such as stomata or impermeable cuticles, so their water content depends on the humidity in the surrounding environment (Thielen et al, 2021). However, low water demand, high drought tolerance (Chen et al, 2020), the ability to grow actively only when water is available, and to recover without physiological damage even after complete drying out for an extended period (Oliver et al, 2005) compensate the lack of dedicated structures.…”