SMR01 Konza Prairie grassland soil microbial responses to long-term management of N availability

Summary

Short name: 

SMR01

Abstract: 

Anthropogenic actions have significantly increased biological nitrogen (N) availability on a global scale. In tallgrass prairies, this phenomenon is exacerbated by land management changes, such as fire suppression. Historically, tallgrass prairie fire removed N through volatilization, but fire suppression has contributed to increased soil N availability as well as woody encroachment. Because soil microbes respond to N availability and plant growth, these changes may alter microbial composition and important microbially-mediated functions. Grassland management affects the soil environment on multiple time scales including short (fertilization or fire event), seasonal (growing vs. non-growing season), and long-term (decadal plant turnover and nutrient accumulation), therefore my goal was to understand community variability at different time scales affecting the population and community dynamics of soil microbes. I predicted soil microbes would be sensitive to environmental changes at all time scales, seasonal variation would reflect increased plant rhizodeposit-supported populations during summer and decomposers during winter, and long-term fire suppression and chronic fertilization would drive soil microbial community turnover associated with accumulation of plant litter and N.

Soil microbial responses to short-term fire/fertilization events were minimal, while microbial population sizes fluctuate seasonally and synchronously, and microbial community composition varied more with management history than at shorter time scales. Bacterial populations increased 10x during growing-season plant rhizodeposition, while fungal populations were less dynamic, but decreased in fall, possibly reflecting a shift to subsistence on soil organic matter. In contrast, microbial community composition was seasonally stable, but distinct between long-term management treatments, which may indicate accumulation of niche-defining plant or soil properties over decades. Prokaryotic communities responded to altered N availability via both fertilization and loss due to fire, with the highest abundance of "copiotrophic" (r-selected) taxa in unburned, fertilized soils. Fungal communities responded to N fertilization with higher abundance of arbuscular mycorrhizal fungi, pathogens, and saprotrophs, possibly due to changes in nutrient stoichiometry and litter availability in fertilized plots. However, fungal response to fire was largely independent of N availability, and plant community differences were correlated with fungal, but not bacterial, community composition, highlighting the likely nutritional codependence of fungi and plants, and fungal competitive advantages for plant litter substrates. The timing of changes in soil microbial communities is critical for plant nutrition and nutrient cycling in prairies, and this novel dataset on the temporal resolution of microbial responses to environmental variability contributes to the broader understanding of ecosystem responses to global change.

Published on EDI/LTER Data Portal

Citation Suggestion: 

Zeglin, L. ., Carson, C. 2020. SMR01 Konza Prairie grassland soil microbial responses to long-term management of N availability . Environmental Data Initiative. http://dx.doi.org/10.6073/pasta/85328650bd2c757d78f175bdfcf20f70.

Data set ID: 

145

EML revision ID: 

1

Data sources: 

Variables: 

DataCode
  • Label:
  • Definition: Dataset code
  • Type: Nominal
  • Missing values: None specified
RecType
  • Label:
  • Definition: Record type
  • Type: Physical quantity
  • Unit: dimensionless
  • Maximum: Not specified
  • Minimum: Not specified
  • Precision: Not specified
  • Missing values: None specified
Sample
  • Label:
  • Definition: Unique sample number
  • Type: Nominal
  • Missing values: None specified
Year
  • Label:
  • Definition: Year of sample was collected
  • Type: Physical quantity
  • Unit: Year (YYYY)
  • Maximum: Not specified
  • Minimum: Not specified
  • Precision: Not specified
  • Missing values: None specified
Month
  • Label:
  • Definition: Month of sample collection (NOV = November 2014, all other months 2015)
  • Type: Nominal
  • Missing values: None specified
Plot
  • Label:
  • Definition: Field Plot IDs
  • Type: Nominal
  • Missing values: None specified
Block
  • Label:
  • Definition: Field Block IDs
  • Type: Nominal
  • Missing values: None specified
Nadd
  • Label:
  • Definition: N addition treatment: no = unfertilized control, yes = fertilized (10 g N as NH4NO3 per square meter per year in early May since 1986).
  • Type: Nominal
  • Missing values: None specified
Burn
  • Label:
  • Definition: Fire treatment: yes = annually burned (in March or April) or no = unburned since 1986.
  • Type: Nominal
  • Missing values: None specified
NaddBurn
  • Label:
  • Definition: Combination of fire (U = unburned or B = annually burned) and fertilization (C = unfertilized or N = fertilized) treatment. There are 4 combinations: UBC, UBN, BC, BN.
  • Type: Nominal
  • Missing values: None specified
GWC
  • Label:
  • Definition: Gravimetric Water Content: field water content in grams water per gram soil after drying overnight at 105 degrees C.
  • Type: Physical quantity
  • Unit: dimensionless
  • Maximum: Not specified
  • Minimum: Not specified
  • Precision: Not specified
  • Missing values: None specified
DNA
  • Label:
  • Definition: DNA yield in micrograms DNA per gram dry soil; CTAB, P:C:IAA, PEG extraction method (DeAngelis et al. 2010, Environmental Microbiology 12, 3137-3149; Zeglin et al. 2016, Environmental Microbiology 18, 146-158).
  • Type: Physical quantity
  • Unit: dimensionless
  • Maximum: Not specified
  • Minimum: Not specified
  • Precision: Not specified
  • Missing values: None specified
16SrRNAgeneCopy
  • Label:
  • Definition: copies of the bacterial 16S rRNA gene per g dry soil, using protocols in Fierer et al. 2005, AEM 71: 4117-4120 and Zeglin et al. 2016, Environmental Microbiology 18, 146-158. "." is missing data due to insufficient template DNA.
  • Type: Physical quantity
  • Unit: dimensionless
  • Maximum: Not specified
  • Minimum: Not specified
  • Precision: Not specified
  • Missing values:
    • . = missing value
fungalITScopy
  • Label:
  • Definition: copies of the fungal ITS region per g dry soil, using protocols in Fierer et al. 2005, AEM 71: 4117-4120 and Zeglin et al. 2016, Environmental Microbiology 18, 146-158. "." is missing data due to insufficient template DNA.
  • Type: Physical quantity
  • Unit: dimensionless
  • Maximum: Not specified
  • Minimum: Not specified
  • Precision: Not specified
  • Missing values:
    • . = missing value
16S_bioproject_accession
  • Label:
  • Definition: Biosample accession number in NCBI SRA Bioproject PRJNA398249.
  • Type: Physical quantity
  • Unit: dimensionless
  • Maximum: Not specified
  • Minimum: Not specified
  • Precision: Not specified
  • Missing values:
    • . = missing value
ITS_bioproject_accession
  • Label:
  • Definition: Biosample accession number in NCBI SRA Bioproject PRJNA509462. "." is missing data due to insufficient sequencing depth
  • Type: Physical quantity
  • Unit: dimensionless
  • Maximum: Not specified
  • Minimum: Not specified
  • Precision: Not specified
  • Missing values:
    • . = missing value

Categories
Dates

Date Range: 

Saturday, November 1, 2014 to Saturday, December 12, 2015

Publication Date: 

Wednesday, February 26, 2020
People

Owner/Creator: 

Contact: