Relationship Between Canopy Dynamics and Stem Volume Production of Four Species Receiving Irrigation and Fertilization

Abstract

We measured the effects of irrigation and varying levels of fertilization on intercepted photosynthetically active radiation (IPAR), projected leaf area index (LAI), and foliar nitrogen concentration ([N]) in order to determine the relationship between resource availability, canopy size, and stem-volume growth. Stands of sycamore (Platanus occidentalis L.), sweetgum (Liquidambar styraciflua L.), loblolly pine (Pinus taeda L.), and slash pine (Pinus elliottii Engelm.) planted in 1997 near Mount Pleasant, GA, received five treatments: control, irrigation only, and irrigation with 57, 85, and 114 kg N ha^-1 year^-1. Beginning in March 2001, sampling for foliar [N], IPAR, and leaf litter were conducted approximately every 6 weeks. Irrigation and fertilization increased stem-volume growth during the 2001 growing season. Annual IPAR and LAI were well correlated with stem-volume growth (r² = 0.80, r² = 0.75, respectively—averages of four species). Foliar [N] and stem-volume growth were significantly correlated for sweetgum (r² = 0.76) and sycamore (r² = 0.80). These results indicate that IPAR is the best predictor and may be the primary driver of stem-volume growth.

Parent Publication

• Proceedings of the 12th biennial southern silvicultural research conference

Citation

Allen, Chrisopher B; Will, Rodney E.; Sarigumba, Terry; Jacobson, Marshall A.; Daniels, Richard F.; Kennerly, Stephen A. 2004. Relationship Between Canopy Dynamics and Stem Volume Production of Four Species Receiving Irrigation and Fertilization. Gen. Tech. Rep. SRS–71. Asheville, NC: U.S. Department of Agriculture, Forest Service, Southern Research Station. pp. 343-347