Seasonal influences on fungal community structure in unimproved and improved upland grassland soils

Abstract

Seasonal and management influences on the fungal community structure of two upland grassland soils were investigated. An upland site containing both unimproved floristically diverse (U4a) and improved mesotrophic (MG7b) grassland types was selected. Samples from both grassland types were taken at five times in one year. Soil fungal community structure was assessed using fungal automated ribosomal intergenic spacer analysis (ARISA), a DNA-profiling approach. A grassland management regime was found to strongly affect fungal community structure, with fungal ARISA profiles from unimproved and improved grassland soils differing significantly. The number of fungal ribotypes found was higher in unimproved than improved grassland soils, providing evidence that improvement may reduce the suitability of upland soil as a habitat for specific groups of fungi. Seasonal influences on fungal community structure were also noted, with samples taken in autumn (October) more correlated with change in ribotype profiles than samples from other seasons. However, seasonal variation did not obscure the measurement of differences in the fungal community structure that were due to agricultural improvement, with canonical correspondence analysis indicating grassland type had a stronger influence on fungal profiles than did season.Key words: upland grasslands, fungal automated ribosomal intergenic spacer analysis, seasonality, improvement, canonical correspondence analysis.

Temporal variation overshadows the response of leaf litter microbial communities to simulated global change

“…Although previous studies have examined the response of microbial composition to environmental change over multiple years (for example, Sheik et al, 2011;Gutknecht et al, 2012), only a handful have considered the effect of seasonal variation on these responses (for example, Lage et al, 2010;Bell et al, 2014). However, the fast generation times of microbes mean that composition can turnover quickly, even across seasons (Bardgett et al, 1999;Kennedy et al, 2006;Habekost et al, 2008;Cregger et al, 2012;Gutknecht et al, 2012). We hypothesize that this high background variability will have several, important consequences for global change responses.…”

Analysis of Fungal Flora in Indoor Dust by Ribosomal DNA Sequence Analysis, Quantitative PCR, and Culture

“…The latter benefit is especially valuable in indoor studies since the main exposure hazards relating to indoor microbial contamination are not dependent on viability (5,26). Molecular methods most often used in fungal studies include conventional or quantitative PCR (qPCR) specific for fungal species or groups (15,18,23,75), universal fungal PCR combined with denaturing gradient gel electrophoresis (DGGE) or temperature gradient gel electrophoresis (4,62,65), terminal or conventional restriction fragment length polymorphism analysis (7,15), and simple labeling-based fingerprinting methods (36). Furthermore, universal fungal PCR combined with cloning and restriction fragment length polymorphism analysis and/or DNA sequencing of cloned fragments has been used (4,7,21,34,37), as well as probing methods (25,44,80).…”

Diversity of putatively toxigenic Aspergillus species in maize and soil samples in an aflatoxicosis hotspot in Eastern Kenya

“…Here, the reverse was reported, A. niger dominating (39 isolates) followed by A. flavus (13 isolates). Such variations can be due to differences in the sampling strategies (McHugh et al, 2014) or even species overlap as seasons change, hence the time of sampling is critical (Kennedy et al, 2006). In their work, Odhiambo et al (2013) sampled 2 weeks after harvest as opposed to 2 months in this study.…”