Mediterranean grassland soil fungi: Patterns of biodiversity, functional redundancy and soil carbon storage

Abstract

Soil organic matter is a relevant carbon reservoir and CO2 sink in temperate grassland ecosystems and increased carbon uptake may mitigate climate change. Relatively little is known about the relationship between ecosystem function and soil fungal biodiversity in grasslands. However, this relationship is important because the saprotrophic microorganisms within the decomposer chain may, given their important role in the decomposition processes of litter and dead roots, control soil carbon storage. In this study, we provide the first empirical evidence of natural patterns of soil fungal biodiversity and soil carbon storage in Mediterranean grasslands at different elevations. We observed an asymptotic relationship between morphological and functional trait richness and fungal biodiversity. This relationship is consistent with the redundancy hypothesis of species diversity and ecosystem function. A limited number of fungal species is sufficient to attain morphological and functional variability in the soil fungal assemblages in these grasslands. We found that increasing fungal biodiversity and biochemical specialization were related to higher soil carbon storage (at a higher altitudes and lower slope position), even in fenced-off grasslands. We discuss the main ecological mechanisms controlling soil carbon storage in grasslands within the framework of a conceptual model. © 2008 Società Botanica Italiana

Relationships between plant traits, soil properties and carbon fluxes differ between monocultures and mixed communities in temperate grassland

“…In both monocultures and communities, soil microbial community did not explain C fluxes, even though plant identity can control soil microbial community composition in this grassland (Leff et al, ). The lack of influence of the soil microbial community on C fluxes is possibly due to high functional redundancy in microbial communities (Persiani, Maggi, Montalvo, Casado, & Pineda, ). Interestingly, shoot biomass was a strong predictor of ecosystem respiration in both the monocultures and mixed communities, and of net ecosystem exchange in monocultures.…”

Biotransformation of β-hexachlorocyclohexane by the saprotrophic soil fungus Penicillium griseofulvum

“…Fungal isolation was carried out from polluted soil samples using the dilution plate method according to Persiani et al (2008). The culture medium used was soil extract agar prepared using soil from the sampling area (Maggi et al, 2005).…”

Composition, uniqueness and variability of the epiphytic bacterial community of the green alga Ulva australis

“…This conclusion is consistent with the redundancy hypothesis (Naeem, 1998), which assumes that more than one species is capable of performing a specific role within an ecosystem, conferring ecosystem functions a degree of resilience to disturbance. Although originally proposed for communities of macroorganisms, this hypothesis has been tested and supported for microbial communities both in laboratory microcosms (Bell et al, 2005;Leflaive et al, 2008) and in situ soil communities (Yin et al, 2000;Persiani et al, 2008). Functional redundancy has also been shown in algal-associated bacterial communities, in which bacteria from a range of taxa within the community were shown to be able to induce normal thallus morphology on the green alga Ulva linza (Marshall et al, 2006).…”