Hokenstrom, Jay C., authorMcConnell, William J. (William Johnston), 1922-, advisorHoover, Marvin D., committee memberCarlson, Clarence A., committee memberMeiman, James R. (James Richard), committee member2007-01-032007-01-031976http://hdl.handle.net/10217/80812Subsurface water was collected from three 3.4 ha treatment sites during the summers of 1973 and 1974 to determine the effect of clearcutting lodgepole pine on the concentration of nutrients in subsurface water. One site was uncut; the other two sites, a "new" and an "old" clearcut, were clearcut in 1972 and 1965, respectively. Water quality was examined by collecting soil water samples from depths of 1.0, .75, .50 and .10 m with tube-tension lysimeters on each of the three sites. Sampling was conducted from late May to early October in 1973, and from mid-May until the end of July in 1974. When compared to the uncut site, average soil water concentrations during 1973 from the 1.0 m deep lysimeters were higher from the "new" clearcut by 79 percent for N03 , 58 percent for Ca, and 33 percent for PO4. For the same period, NH4 and Cl from the "new" clearcut were 42 and 32 percent less, respectively. In 1974, average concentrations of N03 and Ca were 1,079 and 93 percent greater from the "new" clearcut than from the uncut site during the sampling period while tannins, which were only measured in 1974, were about equal in concentration to those from the uncut site. Average concentrations from the "old" clearcut during 1973 were greater than from the uncut area by 711 percent for N03, 50 percent for Ca, and 50 percent for PO4. Average soil water concentrations of NH4 and Cl from the "old" clearcut were 50 to 59 percent less, respectively. During 1974, average concentrations from the "old" clearcut were greater than from the uncut area by 672 percent for N03 and 27 percent for Ca, and less than from the uncut site by about 39 percent for tannins. The data suggest that, following clearcutting of lodgepole pine forests, significant increases in soil water concentrations of nitrate and calcium can be expected for up to 9 years after cutting. Implications of nutrient additions to streams draining clearcut areas are discussed.doctoral dissertationsengCopyright and other restrictions may apply. User is responsible for compliance with all applicable laws. For information about copyright law, please see https://libguides.colostate.edu/copyright.Soil chemistryForest soilsLodgepole pineText