Compatible Stem Taper and Total Tree Volume Equations for Loblolly Pine Plantations in Southeastern Arkansas

A system of equations was used to produce compatible outside-bark stem taper and total tree volume equations for loblolly pine (Pinus taeda L.) plantations in southeastern Arkansas. Paired height diameter stem measurements were obtained from trees located in one 45-year-old unthinned plantation. After fitting and integrating the stem taper equation to total tree height, an individual tree constant form factor volume equation was obtained. The stem taper equation can also be integrated to any merchantable height to obtain merchantable volume. To see how the constant form factor volume equation predicts outside bark volume for trees vastly different than those used in model fitting, trees were harvested from a 17-yearold loblolly pine plantation in southeastern Arkansas. Predictions from the volume equation developed during this research were compared to three other commonly used volume equations. Validation results showed the current constant form factor equation produced the best predictions

Progress Report: Forest Fertilization Effects on the Understory Community

Most forest soils in the Intermountain Northwest have nutrient deficiencies of some kind, especially nitrogen. Overstory conifer trees respond favorably following fertilization in the Intermountain Northwest. However, knowledge of fertilization effects on understory vegetation growth in mixed-conifer stands in the Intermountain Northwest is minimal. The effects of overstory density on understory vegetation response to fertilization in the Intermountain Northwest is also limited. Information about whether fertilization of understory vegetation causes species composition. species diversity, and wildlife habitat to change through time in mixed-conifer stands in the Intermountain Northwest is scarce. Knowledge of the long term effects of fertilization treatments on understory vegetation characteristics in the Intermountain Northwest is lacking. Fertilization may not produce statistically significant responses in understory vegetation growth until several years after application. This study is an attempt to quantify affects a short time after application and to establish monitoring plots. The IFTNC plans to use these study areas for a long-term assessment. Understory vegetation may show more response immediately after fertilization or more response several years after fertilization

Operational Multi-nutrient Fertilization Affects Production of Understory Vegetation

This study quantified the effects of operational multi-nutrient fertilization on understory shrub, forb, and grass production in forests of eastern Oregon, Washington, and Idaho. The greatest understory response to fertilization occurred in low density overstory stands. One additional cattle Animal Unit Month (AUM) can be produced per acre, one year following treatment, in stands with overstory basal area less than 50 ft.2/ac. One additional white-tailed deer equivalent AUM can be produced in stands with less than 75 ft.2/ac. overstory basal area. Multi-nutrient fertilization is an effective treatment for increasing understory production and generally improving wildlife habitat and rangeland yield in addition to tree overstory growth and yield

Progress Report: Forest Fertilization Effects on the Understory Community

Most forest soils in the Intermountain Northwest have nutrient deficiencies of some kind, especially nitrogen. Overstory conifer trees respond favorably following fertilization in the Intermountain Northwest. However, knowledge of fertilization effects on understory vegetation growth in mixed-conifer stands in the Intermountain Northwest is minimal. The effects of overstory density on understory vegetation response to fertilization in the Intermountain Northwest is also limited. Information about whether fertilization of understory vegetation causes species composition. species diversity, and wildlife habitat to change through time in mixed-conifer stands in the Intermountain Northwest is scarce. Knowledge of the long term effects of fertilization treatments on understory vegetation characteristics in the Intermountain Northwest is lacking. Fertilization may not produce statistically significant responses in understory vegetation growth until several years after application. This study is an attempt to quantify affects a short time after application and to establish monitoring plots. The IFTNC plans to use these study areas for a long-term assessment. Understory vegetation may show more response immediately after fertilization or more response several years after fertilization