TY - JOUR T1 - A before-and-after assessment of patch-burn grazing and riparian fencing along headwater streams JF - Journal of Applied Ecology Y1 - 2016 A1 - Larson, D.M. A1 - W. K. Dodds A1 - M.R. Whiles A1 - .Thompson, T.R. A1 - Fulgoni, J.N. AB -
  1. Fire and grazing are common in grasslands world-wide to maintain grass cover and cattle production. The effects of fire, cattle grazing and riparian fencing efficacy on prairie stream ecology are not well characterized at catchment scales.
  2. We examined alterations to stream water quality and biology from patch-burn grazing (PBG) in tallgrass prairie during a five-year, replicated, catchment scale experiment that used a Before-After/Control-Impact (BACI) design and was analysed by mixed-effects models. Treatments included two patch-burned control catchments (fire but no grazers) and PBG in two riparian-fenced and two unfenced catchments. We assessed the effectiveness of riparian fencing for mitigating potential water quality impacts by monitoring water quality and riparian usage by cattle via Global Positioning System.
  3. Riparian fences effectively excluded cattle; however, in unfenced pastures, cattle aggregated along streams 10–20% of the grazing season.
  4. After initiation of PBG, we detected large increases in some nutrients, Escherichia coli, algal biomass, primary productivity and community respiration in all catchments with PBG. Some water quality variables, such as E. coli concentrations, recovered quickly after cattle were removed from pasture, which indicated resiliency.
  5. Riparian fencing moderately reduced the impacts to stream variables, indicating either overland flow and/or subsurface flow allowed nutrients and bacteria to enter the streams.
  6. Synthesis and applications. Patch-burn grazing is a measurable disturbance that can alter the ecological condition of streams. Riparian fencing lessened the degree of impact, yet some water quality variables still exceeded regional reference conditions. Managers will need to assess the costs of riparian fencing compared to the moderate benefits that fencing provides to water quality.
VL - 53 UR - https://besjournals.onlinelibrary.wiley.com/doi/full/10.1111/1365-2664.12692 IS - 5 ER - TY - JOUR T1 - Blazing and grazing: influences of fire and bison on tallgrass prairie stream water quality JF - Freshwater Science Y1 - 2013 A1 - Larson, D.M. A1 - Grudzinski, B.P. A1 - W. K. Dodds A1 - Daniels, M.D. A1 - Skibbe, A.M. A1 - Anthony Joern KW - Bison bison KW - Bos bison KW - burning KW - Grasslands KW - grazers KW - prescribed fire KW - streams KW - tallgrass prairie KW - total nitrogen KW - total phosphorus KW - total suspended solids AB -

Fire and grazers (such as Bison bison) were historically among the most important agents for maintaining and managing tallgrass prairie, but we know little about their influences on water-quality dynamics in streams. We analyzed 2 y of data on total suspended solids (TSS), total N (TN), and total P (TP) (3 samples per week per stream during flow) in 3 prairie streams with fire and bison grazing treatments at Konza Prairie Biological Station, Kansas (USA), to assess whether fire and bison increase the concentrations of these water-quality variables. We quantified the spatial and temporal locations of bison (∼0.21 animal units/ha) with Global Positioning System collars and documented bison trails, paw patches, wallows, and naturally exposed sediment patches within riparian buffers. Three weeks post-fire, TN and TP decreased (t-test, p < 0.001), but TSS did not change. Bison spent <6% of their time within 10 m of the streams, increased the amount of exposed sediment in the riparian areas, and avoided wooded mainstem branches of stream (χ2 test, p < 0.001). Temporal trends suggest that low discharge or increased bison density in the stream may increase TSS and TP during the summer months. Our results indicate a weak connection between TSS and nutrients with bison access to streams over our 2-y study and indicate that low TSS and nutrients characterize tallgrass prairie streams with fire and moderate bison densities relative to surrounding land uses.

VL - 32 UR - https://www.journals.uchicago.edu/doi/10.1899/12-118.1 ER - TY - JOUR T1 - Ecosystem characteristics of remnant, headwater tallgrass prairie streams JF - Journal of Environmental Quality Y1 - 2013 A1 - Larson, D.M. A1 - W. K. Dodds A1 - Jackson, K.E. A1 - M.R. Whiles A1 - Winders, K.R. AB -

North America has lost >95% of its native tallgrass prairie due to land conversion, making prairie streams one of the most endangered ecosystems. Research on the basic ecosystem characteristics of the remaining natural prairie streams will inform conservation and management. We examined the structure and function of headwater streams draining tallgrass prairie tracts at Osage Prairie in Missouri and the Konza Prairie Biological Station in Kansas and compared those values with literature values for streams draining agricultural watersheds in the region. We quantified physicochemical and biological characteristics for 2 yr. Streams at Osage and Konza were characterized by low nutrients and low suspended sediments (substantially lower than impacted sites in the region), slight heterotrophic status, and high temporal variability. Suspended sediments and nutrient concentrations were generally low in all prairie streams, but storms increased concentrations of both by 3- to 12-fold. Spring prescribed burns were followed by a slight increase in chlorophyll a and decreased nutrients, potentially due to greater light availability. Benthic macroinvertebrate communities at Osage showed seasonal patterns that were probably linked to variable hydrology. We found nine amphibian species using the Osage streams as habitat or breeding sites, but little usage at Konza was probably due to dry conditions and low discharge. Our study indicates that two remnant tallgrass prairie streams along a longitudinal gradient are fairly similar in terms of physicochemical features and have good water quality relative to agricultural watersheds but can differ considerably in macroinvertebrate and amphibian abundance.

VL - 42 UR - https://dl.sciencesocieties.org/publications/jeq/abstracts/42/1/239 ER -