Growth response of upland oak stands in the Boston Mountains to nitrogen fertilization
| Authors: | David L. Graney, Paul A. Murphy |
| Year: | 1993 |
| Type: | Paper |
| Station: | Southern Research Station |
| Source: | Proceedings of the seventh biennial southern silvicultural research conference. Gen. Tech. Rep. SO-93 |
Abstract
Seventy 1-acre plots representing a range of site indexes and stand ages were installed on the Ozark National Forest between 1975 and 1977. Plots were selected so they could be paired according to similarities in age, site index, species composition, and stand structure·. The 35 plot pairs were thinned to residual densities of 40 to 100 percent stocking. One plot in each pair was fertilized with 300 pounds per acre of nitrogen applied as ammonium nitrate in the spring of the second growing season following thinning. Plots were inventoried before thinning and 5 and 10 years after thinning. Regression analysis was used to analyze the effect of age, site index, residual basal area, growth period, and fertilizer treatment on basal area and total cubic foot volume growth. The fertilizer application affected survivor growth and ingrowth of both volume and basal area. However, mortality apparently was not affected by fertilization. Some growth componentsalso differed by 5-year growth periods. The findings indicate that these stands will respond to fertilizer treatments for 5 to 10 years after application.