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Defoliation effects on growth and mortality of three young southern pine species

Formally Refereed
Download (PDF 3.40 MB): https://research.fs.usda.gov/download/treesearch/52491.pdf

Abstract

Foliage from loblolly (Pinus taeda L.), slash (P. elliottii Engelm.), and longleaf (P. palustris Mill.) pines was hand plucked to isolate the effects of level and timing of foliage removal on growth and mortality. Slash and loblolly pine received one of five defoliation treatments during one of four months: January, April, July, or October. Longleaf pine received one of three defoliation treatments during one of five 2-week periods from September to December. Growth and mortality were measured for each species for several years after treatment. Increased defoliation resulted in increased growth loss. Only total October defoliation caused significant mortality in loblolly and longleaf pine and moderate mortality in slash pine. Estimated difference in volume between control and defoliated trees after 5 or 6 years ranged from 0 to 2.3 ft3 (about 30 percent) per tree depending on species, defoliation season, and amount of defoliation. Trees receiving 95 percent or greater defoliation were generally smaller than the control trees after 13 or 19 years posttreatment.

Citation

Weise, David R.; Wade, Dale D.; Johansen, Ragnar W.; Preisler, Haiganoush K.; Combs, David C.; Ach, Edward E. 2016. Defoliation effects on growth and mortality of three young southern pine species. Res. Pap. PSW-RP-267. Albany, CA: U.S. Department of Agriculture, Forest Service, Pacific Southwest Research Station. 70 p.
Citations