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Submitted to: Society for Range Management Meeting Proceedings
Publication Type: Abstract Only Publication Acceptance Date: 7/31/2000 Publication Date: 3/1/2001 Citation: NORTHUP, B.K. IMPACTS OF GROWING CONDITIONS AND TILLER DEVELOPMENT ON ABOVEGROUND PRIMARY PRODUCTION IN A SOUTHERN TALLGRASS PRAIRIE, OKLAHOMA. SOCIETY FOR RANGE MANAGEMENT MEETING PROCEEDINGS. 2001. p. 2-3. Interpretive Summary: Abstract Only. Technical Abstract: Conditions during the growing season and phenological development of grass tillers impact herbage production of grasslands. A study was undertaken to examine effects of time of growing season, soil moisture, and tiller development of key species on aboveground net primary production (NPP) in a southern tallgrass prairie, Oklahoma. Data were collected from 8 replicate eplots (10 x 10 m, sub-divided into 2 x 2 m sub-plots), in March through October 2000, established at each of two slope positions (top and bottom of slopes) ona Norge silt loam (Udic Paleustoll) soil (loamy prairie site) of an area burned in mid-March. Data were collected at 14-day intervals from April (30 days post-burn) through October. Aboveground biomass was collected from 0.5 m2 quadrats randomly placed within one sub-plot (randomly chosen) per plot at each collection date, divided into green and standing dead fractions, and dry weights determined. Additionlly, 75 tillers of both Andropogon gerardii and Schizachyrium scoparium (key species that produce 40 to 45% of total herbage on Norage sites), were collected, maturity determined by the Nebraska growth staging system, and mean dry weights defined. Soil moisture was determined from cores collected at three depths of the profile (0-10, 10-25, and 25-50 cm). Data were analyzed by best subsets regression procedures, with length of season, soil moisture, tiller maturities and weights the independent variables, and NPP per unit area the dependent variable. Results from the first year of data collection on the study will be presented and discussed. |
