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

GARIBOTTI, I.; TABENI S.; GONZALEZ POLO, M.

FUNCTIONAL ECOLOGY

WILEY-BLACKWELL PUBLISHING, INC

Lugar: Londres; Año: 2018 vol. 32 p. 1065 - 1078

0269-8463

Understanding the importance of biotic community structure on ecosystemfunctioning, and whether communities inhabiting different microhabitats in highlyheterogeneous areas provide different ecological functions is a challenge in ecologicalresearch in the face of biodiversity and habitat loss. Biological soil crusts (BSCs) havebeen largely treated as unique entities, and have been mostly examined in interspacesbetween perennial plants, limiting current understanding of their role as drivers ofecosystem functioning and their relative contribution in comparison to vascular plants.2. We assessed the role of BSCs on ecosystem functioning in vegetated patches andinterspaces, and how individual soil functions and ecosystem multifunctionality arerelated to changes in BSC species- and community-level attributes. We contemplatednine ecosystem functions associated with soil water dynamics, nutrient cycling anderosion potential.3. We found that vegetated patches improve infiltration rates, soil stability and netpotential nitrogen (N) mineralization compared to interspaces, and thus dominatemultifunctionality. However, well-developed BSCs improve soil moisture and N pool inboth microsites, and are multifunctional stabilizing soils and regulating soil moistureand infiltration in the interspaces. BSC surface microstructure, including changes intotal cover, species richness, morphological functional groups and surfacediscontinuities, has significant effects on soil moisture. Differences in soil N andphosphorous are mostly related to the presence of BSC-lichens. The effect of BSCs onmultifunctionality varies in dependence of the particular set of functions that are seekto simultaneously maximize.4. Our results suggest that vascular plants and BSCs have idiosyncratic effects ondifferent key ecosystem functions and multifunction, and BSCs substitute vascularplants in stabilizing soils and regulating water dynamics in the interspaces. BSCs greatly contribute to small scale heterogeneity in the functioning of vegetated patches andinterspaces, hence consideration of BSCs in different microsites is essential forenhancing our understanding of their functional relevance at a regional scale. Inaddition, quantification of BSC microstructure is crucial, owing to the contrastingeffects of BSC species- and community-level attributes on different functions andmultifunction.