Linking biological soil crust attributes to the multifunctionality of vegetated patches and interspaces in a semiarid shrubland

Abstract

Understanding the importance of biotic community structure on ecosystem functioning, and whether communities inhabiting different microhabitats in highly heterogeneous areas provide different ecological functions is a challenge in ecological research in the face of biodiversity and habitat loss. Biological soil crusts (BSCs) have been largely treated as unique entities, and have been mostly examined in interspaces between perennial plants, limiting current understanding of their role as drivers of ecosystem functioning and their relative contribution in comparison to vascular plants. We assessed the role of BSCs on ecosystem functioning in vegetated patches and interspaces, and how individual soil functions and ecosystem multifunctionality are related to changes in BSC species‐ and community‐level attributes. We contemplated nine ecosystem functions associated with soil water dynamics, nutrient cycling and erosion potential. We found that vegetated patches improve infiltration rates, soil stability and net potential nitrogen (N) mineralization compared to interspaces, and thus dominate multifunctionality. However, well‐developed BSCs improve soil moisture and N pool in both microsites, and are multifunctional stabilizing soils and regulating soil moisture and infiltration in the interspaces. BSC surface microstructure, including changes in total cover, species richness, morphological functional groups and surface discontinuities, has significant effects on soil moisture. Differences in soil N and phosphorous are mostly related to the presence of BSC‐lichens. The effect of BSCs on multifunctionality varies in dependence of the particular set of functions that are sought to simultaneously maximize. Our results suggest that vascular plants and BSCs have idiosyncratic effects on different key ecosystem functions and multifunction, and BSCs substitute vascular plants in stabilizing soils and regulating water dynamics in the interspaces. BSCs greatly contribute to small‐scale heterogeneity in the functioning of vegetated patches and interspaces, hence consideration of BSCs in different microsites is essential for enhancing our understanding of their functional relevance at a regional scale. In addition, quantification of BSC microstructure is crucial, owing to the contrasting effects of BSC species‐ and community‐level attributes on different functions and multifunction. A http://onlinelibrary.wiley.com/doi/10.1111/1365-2435.13044/suppinfo is available for this article.

More drought leads to a greater significance of biocrusts to soil multifunctionality

“…Biodiversity loss is an important ecological problem in the current scenario of climate change, which would cause the degradation of ecosystem functions and services (Donatti et al., 2020; Rodriguez‐Caballero et al., 2018; Sanchez‐Bayo & Wyckhuys, 2019). The relationships between biodiversity and soil functions are critical issues in ecological research (Garibotti et al., 2018). At present, soil multifunctionality (SMF) is more representative than a single soil function in terms of the ecosystem responses to biodiversity alterations, and most studies on this topic have been conducted on terrestrial plants, bacteria, soil invertebrates and seagrasses (Benvenutto‐Vargas & Ochoa‐Hueso, 2020; Heilpern et al., 2020; Wagg et al., 2019; Zhou et al., 2020).…”

“…Our understanding of the mechanisms responsible for sustaining diversity and their importance for SMF has greatly improved; however, three major knowledge gaps exist regarding drylands: First, soil microbial diversity studies have focused mainly on bare soil. The microbial community in biocrusted soil was more abundant and the community structure was significantly different from bare soil, but little is known about the combined effects of climate and biocrust development on driving SMF (Delgado‐Baquerizo et al., 2016; Garibotti et al., 2018; Li et al., 2020; Zhang et al, 2016). Second, at a local scale, studies have demonstrated that biocrust development can promote interactions within community and SMF improvement (Li et al., 2020), but less is known about how the variations of biocrust development affect SMF across the geographical scale (Delgado‐Baquerizo et al., 2016; Garibotti et al., 2018).…”

“…More importantly, biocrust thickness and cover, as well as microbial diversity, gradually increase with biocrust development (Liu et al., 2017, 2019; Zhang et al, 2016). Biocrust development and the accompanying functional traits also indirectly affect SMF by altering the community abundance and composition of both plant (Havrilla et al., 2019) and soil microbial communities (Garibotti et al., 2018; Su, Chen, et al., 2020), as well as their interactions (Havrilla et al., 2019). However, the extent to which changes in SMF are indirectly affected by plant species and soil microbial communities, as mediated by biocrust development, has been rarely quantified (Delgado‐Baquerizo et al., 2016; Garibotti et al., 2018).…”

Divergence among biological soil crust communities developing under different environmental conditions

“…In addition, field sampling was performed to compare the structure of cultured and natural communities in the different microhabitats. (Garibotti et al, 2018).…”

“…Natural soil samples and soil samples taken from the experimental pots at the end of the experimentation period were analyzed to measure some soil properties and processes that are linked to the functioning of the BSCs on nutrient cycling, water erosion potential and water dynamics (Garibotti et al, 2018). Soil samples were sieved using a 2-mm mesh and air-dried for the measurement of pH in water and electrical conductivity (1:2.5 and 1:5 soil:water ratio, respectively).…”