Date of Graduation

2017

Document Type

Thesis

Degree Type

MS

College

Davis College of Agriculture, Natural Resources and Design

Department

Agricultural and Resource Economics

Committee Chair

Jamie Schuler

Committee Co-Chair

Jingjing Liang

Committee Member

Gary Miller

Abstract

Current models to predict post-harvest success rely upon pre-harvest regeneration assessments, which rarely occur. Furthermore, these models lack management recommendations to improve regeneration success of naturally regenerating desired hardwood species following overstory removal. Factorial combinations of weeding and fertilization were randomly assigned to individual naturally regenerating black cherry (Prunus serotina Ehrh.), chestnut oak (Quercus montana Willd.), white oak (Quercus alba L.), and red oak (Q. rubra L., Q. velutina Lam., and Q. coccinea Muenchh.) seedlings in the spring of 2015, three growing seasons post-harvest. Factorial ANOVA models with size at treatment application as a covariate were developed and showed species-specific height, root collar diameter (RCD), and survival responses to treatment application. Additionally, these responses were influenced by pressures from white-tailed deer (Odocoileus virginianus Zimm.) and competing vegetation. Height growth responses suggest that weeding allows for crown expansion and increased herbivory occurrence which causes a decrease in height growth, particularly when taller stems were treated. Species-specific responses were observed for RCD growth when weeded and for height growth when fertilized. Regardless of species, fertilization increased average RCD growth by 0.7 mm (p = 0.005). The height and RCD growth responses suggest that nutrients were limiting growth, particularly for black cherry. Survival across all treatments and species for the duration of the study was 92%, suggesting that though nutrients were limiting growth, resources were not meaningfully limiting. As these resources become more limiting with canopy closure, the effect of weeding and fertilization is expected to become more pronounced.;Based on the species-specific responses to weeding and fertilization, predictive equations for second year height post-treatment were developed for each species. These equations provide managers with a useful tool to predict the height of naturally regenerating seedlings two growing seasons post-treatment in response to post-harvest weeding and fertilization treatments. In time, continued monitoring will enable the development of models that can predict dominance probabilities of the desired individual seedlings. These findings show that direct-application of weeding and fertilization may be effective to bolster the success and growth of young naturally regenerating seedlings and influence species composition.

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