The purpose of this data set is to monitor long-term changes in microbial biomass on the belowground plots due to the effect on annual burning, mowing and nitrogen and phosphorus fertilization.
The goals and focal research questions are copied below from the Nutrient Network website. More information can be found at nutnet.org.
NutNet focal research questions: (1) How general is our current understanding of productivity-diversity relationships? (2) To what extent are plant production and diversity co-limited by multiple nutrients in herbacoues-dominated communities? (3) Under what conditions do grazers or fertilization control plant biomass, diversity, and composition?
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.
The concentration and isotopic composition of soil carbon and nitrogen were measured from select archived soil cores originally collected for the NSC01 dataset using an isotope ratio mass spectrometer coupled with an elemental analyzer. These soil cores were collected from the lowlands (25 cm depth) of four experimental watersheds in 1982, 1987, 2002, 2010, and 2015. The four experimental watersheds are 001d, n01b, 020b, and n20b.
Data describe the soil chemistry and microbial diversity at the Belowground Plot Experiment (BGP) from the 2017 summer growing season. Whole plot-scale nitrogen fertilization at the BGP ceased in 2017. Four subplots within each historically fertilized plot were established to continue the annual fertilization treatment for soil chemistry and microbial diversity.
We conducted a “home vs. away” plant-soil feedback greenhouse experiment using two C3 grass species (Bromus inermis and Pascopyrum smithii) grown in soil collected from Konza Prairie. We used a closed-circuit CO2 trapping method and isotopic analysis to differentiate between root-derived and SOM-derived CO2 production. We investigated how soil chemistry and soil bacterial communities differed in soils with a history of B. inermis vs soils with a history of P. smithii.
Climate change is expected to shift precipitation regimes in the North American Central Plains with likely impacts on ecosystem functioning. In tallgrass prairies, water and nitrogen (N) can co-limit ecosystem processes, so changes in precipitation may have complex effects on carbon (C) and N cycling. Rates of N supply such as N mineralization and nitrification respond differently to short- and long-term patterns in water availability, and previous climate patterns may exert legacy effects on current N cycling that could alter ecosystem sensitivity to current precipitation regimes.
The stream water samples are the same as collected for the NWC01 dataset. Water samples are frozen (-3 C) in sealed polyvinyl bottles until time of processing. These water samples are thawed, subsampled at 1 mL, and analyzed for delta18O and delta2H using a Picarro L2130-i isotopic water analyzer. Samples are corrected using in-house standards calibrated to the international standard, V-SMOW. The long-term precision for delta18O is 0.1 permil and for delta2H is 1 permil.