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Rillig, M. C.

Publications and source records attributed to Rillig, M. C..

5 recordsLinked to original sources

Soils from different landscape elements diverge in response to multiple global change factors

Global change factors (GCFs) are known to affect terrestrial ecosystems across a range of land-use types, including farmlands, grasslands, and forests. However, it remains unclear whether different landscape elements within the same region respond differently to the same global change pressures. Here, we investigated this question using four soils collected from co-located farmland, grassland, pine forest, and oak forest, representing distinct landscape elements under the same regional climatic conditions. Each soil was exposed to one of six individual GCFs, warming, drought, nitrogen deposition, salinity, microplastics, and antibiotics, as well as to all six factors combined. We found that landscape elements exhibited strongly divergent responses to the same GCFs. The effects on soil functions also varied among soils under combined stress, with responses diverging from different null-model predictions depending on soils and response variable. Moreover, landscape-element specific response patterns became more pronounced under multiple concurrent stressors. Overall, our findings show that landscape heterogeneity represents a mosaic of different capacities to resist and respond to global change, even under shared climatic and geographic conditions. Global change assessments and ecosystem models should therefore better account for landscape-level heterogeneity, and management strategies aimed at enhancing ecosystem resilience should be tailored to individual landscape elements.

ecology

How to build a mycelium: tradeoffs in fungal architectural traits

The fungal mycelium represents the essence of the fungal lifestyle, and understanding how a mycelium is constructed is of fundamental importance in fungal biology and ecology. Previous studies have examined initial developmental patterns or focused on a few strains, often mutants of model species, and frequently grown under non-harmonized growth conditions; these factors currently collectively hamper systematic insights into rules of mycelium architecture. To address this, we here use a broader suite of fungi (31 species including members of the Ascomycota, Basidiomycota and Mucoromycotina), all isolated from the same soil, and test for ten architectural traits under standardized laboratory conditions.\n\nWe find great variability in traits among the saprobic fungal species, and detect several clear tradeoffs in mycelial architecture, for example between internodal length and hyphal diameter. Within the constraints so identified, we document otherwise great versatility in mycelium architecture in this set of fungi, and there was no evidence of trait syndromes as might be expected.\n\nOur results point to an important dimension of fungal properties with likely consequences for coexistence within local communities, as well as for functional complementarity (e.g. decomposition, soil aggregation).

ecology

Growth rate trades off with enzymatic investment in soil filamentous fungi

Saprobic soil fungi drive many important ecosystem processes, including decomposition, and many of their effects are related to growth rate and enzymatic ability. In mycology, there has long been the implicit assumption of trade-off between growth and enzymatic investment, which we here test. Using a set of 31 filamentous fungi isolated from the same ecosystem, we measured growth rate (as colony radial extension) and enzymatic repertoire (activities of four enzymes: laccase, cellobiohydrolase, leucine aminopeptidase and acid phosphatase). Our results support the existence of a trade-off, however only for the enzymes representing a larger metabolic cost (laccase and cellobiohydrolase). Our study offers new insights into functional complementarity within the soil fungal community in a number of ecosystem processes, and experimentally supports an enzymatic investment/ growth rate tradeoff in explaining phenomena including substrate succession.

ecology

Evidence for subsoil specialization in arbuscular mycorrhizal fungi

Arbuscular mycorrhizal (AM) fungal communities are now known to vary with depth in arable land. Here we use two previously published high-throughput Illumina sequencing data sets, and compare a 52 year long chronosequence of recultivated agriculture fields after a topsoil and subsoil mixing event, with a set of undisturbed topsoil and subsoil samples from a similar field. We show that AM taxa identified as subsoil indicators are exclusively present in early stages of the chronosequence, whereas topsoil indicator taxa can be found across the chronosequence, and that similarities from the chronosequence fields to the subsoil communities decrease with time. Our results provide evidence on the ecological specialization of certain AM fungal taxa to deep soil layers.

ecology

Subsoil arbuscular mycorrhizal fungal communities in arable soil differ from those in topsoil

Arbuscular mycorrhizal fungi are recognized as important drivers of plant health and productivity in agriculture but very often existing knowledge is limited to the topsoil. With growing interest in the role of subsoil in sustainable agriculture, we used high-throughput Illumina sequencing on a set of samples encompassing drilosphere, rhizosphere and bulk soil, in both top- and subsoil. Our results show subsoil AMF communities harbor unique Operational Taxonomic Units (OTUs) and that both soil depths differ in community structure both at the OTU and family level. Our results emphasize the distinctness of subsoil AMF communities and the potential role of subsoil as a biodiversity reservoir.

ecology