Publications Published in Soil Biology & Biochemistry

1. Functional shifts of grassland soil communities in response to soil warming. Briones, M. J. I.; Ostle, N. J.; McNamara, N. R.; Poskitt, J..
   Soil Biology & Biochemistry: 2009
   DOI: 10.1016/j.soilbio.2008.11.003
   Notes
   In terrestrial ecosystems most carbon (C) occurs below-ground, making the activity of soil decomposer organisms critical to the global carbon cycle. Temperate grassland ecosystems, contain large, diverse and active soil meso- and macrofauna decomposer communities. Understanding the effects of climate change on their ecology offers a first step towards meaningful predictions of changes in soil organic carbon mineralisation. We examined the effects of soil warming on the abundance, diversity and ecology of temperate grassland soil fauna functional groups, ecosystem net CO2 flux and respiration and plant above- and below-ground productivity in a 2-year plant-soil mesocosm experiment. Low voltage heating cable mounted on a framework of stainless steel mesh provided a constant 3.5 degrees C difference between control and warmed mesocosm soils. Results showed that this temperature increment had little effect on soil respiration and above-ground plant biomass. There was, however, a significant effect on the soil fauna due to warmer conditions and increased root growth, with significant decreases in the numbers in the large oligochaete groups and Prostigmata mites and the re-distribution of enchytraeids to deeper soil layers. Functional groups exhibited individualistic responses to soil warming, with the total disappearance of epigeic species in the case of the ecosystem engineers and an increased diversity of fungivorous mites that, together, produced significant changes in the composition and trophic structure of the fauna community. The observed switch towards a fungal driven food web has important implications for the fate of soil organic carbon in temperate ecosystems subjected to sustained warming. Accordingly, soil biology needs to be properly incorporated in C models to make better predictions of the fate of SOC under warmer scenarios. (C) 2008 Elsevier Ltd. All rights reserved.
   
   
   
2. Methane oxidation and microbial exopolymer production in landfill cover soil. Hilger, H. A.; Cranford, D. F.; Barlaz, M. A..
   Soil Biology & Biochemistry: 2000
   Notes
   In laboratory simulations of methane oxidation in landfill cover soil, methane consumption consistently increased to a peak value and then declined to a lower steady-state value. It was hypothesized that a gradual accumulation of exopolymeric substances (EPS) contributed to decreased methane uptake by clogging soil pores or limiting gas diffusion. This study was conducted to detect and quantify EPS in soil from columns sparged with synthetic landfill gas and from fresh landfill cover cores. Polysaccharide accumulations were detected with alcian blue stain. EPS was observed adhering to soil particles and as strands associated with, but separate from soil grains. Glucose concentrations in laboratory soil columns averaged 426 mg kg(-1) dry soil, while in a column sparged with air the average glucose concentration in a horizon was 3.2 mg glucose kg(-1) dry soil.
   
   
   
3. Methane pool and flux dynamics in a rice field following straw incorporation. Bossio, D. A.; Horwath, W. R.; Mutters, R. G.; van Kessel, C..
   Soil Biology & Biochemistry: 1999
   Notes
   Concerns for air quality have led to legislation restricting rice straw burning in some parts of the world. Consequently, growers must dispose of large amounts of residual rice straw by incorporation into the soil, which may have large effects on CH4 emissions from those fields. Our objective was to characterize how this recent change in management has affected overall CH4 emissions in a California rice field and establish relationships between organic matter availability, CH4 pool sizes and CH4 fluxes. Closed chamber measurements were used to monitor diurnal and post drain fluxes, to describe the seasonal pattern of CH4 emissions and estimate total CH4 fluxes on a large on-farm field trial during the 1997 growing season. Soil redox, temperature and plant growth and yield were also monitored. To establish relationships between CH4 pool sizes and fluxes, soil interstitial CH4 concentrations were monitored in the field and available organic matter in the spring was estimated with a laboratory incubation. Redox values in the soil were found to be 50 mV lower in plots in which straw had been incorporated (275 mV) than those in which it had been burned (225 mV). No significant treatment differences were seen in total soil organic matter contents in the spring. However, available organic matter was 1.5 times higher in straw incorporated than straw burned plots. Methane emissions peaked between 22.00 and 23.00 h on two different diurnal sampling dates. Methane emission after draining was about 10% of the flooded period total. A 5-fold increase in total CH4 emissions over the rice growing season was observed in plots in which rice straw had been incorporated each fall for 4 yr. Total cumulative CH4 flux, 1 May 1 October 1997, was 8.87 g C m
   
   
   
4. Microbial biomass, functional capacity, and community structure after 12 years of soil warming. Frey, S. D.; Drijber, R.; Smith, H.; Melillo, J..
   Soil Biology & Biochemistry: 2008
   DOI: 10.1016/j.soilbio.2008.07.020
   Notes
   We examined the effect of chronic soil warming on microbial biomass, functional capacity, and community structure in soil samples collected from the Soil Warming Study located at the Harvard Forest Long-term Ecological Research (LTER) site. Twelve years of chronic soil warming at 5 degrees C above the ambient temperature resulted in a significant reduction in microbial biomass and the utilization of a suite of C substrates which included amino acids, carbohydrates, and carboxylic acids. Heating significantly reduced the abundance of fungal biomarkers. There was also a shift in the mineral soil microbial community towards gram positive bacteria and actinomycetes. (c) 2008 Elsevier Ltd. All rights reserved.