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This dataset supports a published study on the effects of permafrost thaw on greenhouse gas fluxes and microbial activities at the Alaska Peatland Experiment (APEX), part of the Bonanza Creek LTER, in interior Alaska. The dataset includes autochamber CO2 and CH4 fluxes, net ecosystem exchange, ecosystem respiration, soil temperatures, climate data, microbial qPCR data, soil physical chemistry, soil extract chemistry, and rates of microbial activities, both from lab incubations, and rates derived from an isotope based process model.
Changes in the biomass and structure of soil microbial communities have the potential to impact ecosystems via interactions with plants and weathering minerals. Previous studies of forested long-term (1000s – 100,000s of years) chronosequences suggest that surface microbial communities change with soil age. However, significant gaps remain in our understanding of long-term soil microbial community dynamics, especially for non-forested ecosystems and in subsurface soil horizons. We investigated soil chemistry, aboveground plant productivity, and soil microbial communities across a grassland chronosequence (65,000–226,000 yrs old) located near Santa Cruz, CA. Aboveground net primary productivity (ANPP) initially increased...
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Floodplain surficial soil samples (10 cm depth) were collected from 18 streams in the urbanized Piedmont region of northern Virginia, representing a chronosequence of time (1-10 yrs.) since stream restoration as well as unrestored and reference streams. The samples were analyzed for total carbon (TC), total nitrogen (TN) and total phosphorus (TP) storage, whereas CO2 mineralization potential and equilibrium phosphorus concentration (EPC0) were measured as metrics of nutrient and carbon loss. Samples also were analyzed for soil moisture, pH, particle size, organic matter content, and degree of phosphorus saturation.
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Arid ecosystems are often vulnerable to transformation to invasive-dominated states following fire, but data on persistence of these states are sparse. The grass/fire cycle is a feedback process between invasive annual grasses and fire frequency that often leads to the formation of alternative vegetation states dominated by the invasive grasses. However, other components of fire regimes, such as burn severity, also have the potential to produce long-term vegetation transformations. Our goal was to evaluate the influence of both fire frequency and burn severity on the transformation of woody-dominated communities to communities dominated by invasive grasses in major elevation zones of the Mojave Desert of western...
Understanding of the organic layer thickness (OLT) and organic layer carbon (OLC) stocks in subarctic ecosystems is critical due to their importance in the global carbon cycle. Moreover, post-fire OLT provides an indicator of long-term successional trajectories and permafrost susceptibility to thaw. To these ends, we 1) mapped OLT and associated uncertainty at 30 m resolution in the Yukon River Basin (YRB), Alaska, employing decision tree models linking remotely sensed imagery with field and ancillary data, 2) converted OLT to OLC using a non-linear regression, 3) evaluate landscape controls on OLT and OLC, and 4) quantified the post-fire recovery of OLT and OLC. Areas of shallow (< 10 cm), moderate (≥ 10 cm and...
    map background search result map search result map Cover of Woody and Herbaceous Functional Groups in Burned and Unburned Plots, Mojave Desert, 2009-2013 Flux and Soil Data from the Alaska Peatland Experiment 2014 to 2016 Data of floodplain soil carbon and nutrient retention along a chronosequence of urban stream restorations in Northern Virginia (2022) Data of floodplain soil carbon and nutrient retention along a chronosequence of urban stream restorations in Northern Virginia (2022) Flux and Soil Data from the Alaska Peatland Experiment 2014 to 2016 Cover of Woody and Herbaceous Functional Groups in Burned and Unburned Plots, Mojave Desert, 2009-2013