Effects of Nutrient Amendments and Genotype on StandProductivity and Crown Characteristics in Loblolly Pine(Pinus taeda L.)

by Handest, Joshua A.

Abstract (Summary)

Handest, Joshua A. Effects of Nutrient Amendments and Genotype on Stand Productivity andCrown Characteristics in Loblolly Pine (Pinus taeda L.) (Under the direction of H. Lee Allen andSteven E. McKeand).Two provenances of loblolly pine, with five open-pollinated families from each were analyzed fordifferences in height, volume, leaf area, and various crown characteristics. Families from theNorth Carolina and South Carolina Coastal Plain (ACP) and from the ?Lost-Pines? area of Texas(LPT) were included in the study. In addition to studying potential genetic variation, half of theplots received fertilization treatments so that potential nutrient and genotype x environment(GxE) interactions could be assessed. The stands were established in 1993 and height wasmeasured annually until year 3 when both height and diameter at breast height were measured.Leaf area measurements were made in 1999 using the LI-CORE LAI-2000 PCA and destructiveand non-destructive sampling of individual branches was done to estimate the crowncharacteristicsNutrient additions starting at stand establishment resulted in large gains in juvenile developmentin height, volume, leaf area, and growth efficiency. Fertilization also dramatically increasedfoliage and branch biomass at all crown levels, and also contributes to an early shift of foliagefrom the lower crown to the middle. This is most likely due to early canopy closure. The AtlanticCoastal Plain provenance consistently outperformed the Lost Pine Texas provenance in height,volume, and growth efficiency. The ACP provenance had more foliage, predominately in themiddle crown than the LPT provenance, which may explain some of the productivity differences.There was a significant amount of variation in height, volume, leaf area, and growth efficiencybetween the families of both provenances. Both the vertical distribution and quantity of foliage inthe ACP families may explain some of the variation in volume growth and growth efficiency,though neither show enough of a direct correlation to explain all of it. The crown characteristicsstudied seem to indicate that distribution of foliage itself is more important in explainingdifferences among the LPT families.

Bibliographical Information:

Advisor:Steve McKeand; H. Lee Allen; Marcia Gumpertz

School:North Carolina State University

School Location:USA - North Carolina

Source Type:Master's Thesis



Date of Publication:01/24/2002

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