Performing Department
School of Forest Resources
Non Technical Summary
Two major challenges tomanaging the forests of the Northeastern US during the coming decadewill be 1) how to effectively commercially thin maturing spruce-fir standsand 2) how to improve the species composition of hardwood regeneration in stands dominated by diseased American beech (Fagus grandifolia).This project will help forest landowners meet these challenges using astatewide network of commercial thinning experiments to refine commercial thinning and stand improvement treatments in previously thinned and unthinned stands. A new investigation will help forest managers develop new approaches for improving the qualityof natural hardwoodregeneration instands dominated bydiseased beech.Specifically, this project will: 1) Identify the timing, intensity, and method of commercial thinning prescriptions in spruce-fir stands that can provide logs of a particular diameter and species in a specific period of time and that can maximize the net present value of forest management activities; 2) Identify low-cost and effective silvicultural prescriptions that will shift the species composition of natural hardwood regeneration in partially harvested stands away from diseased beech and toward higher-value sugar maple and yellow birch, and 3) Provide data, models, and conceptual relationships from long-term silvicultural experiments that will help improve growth and yield models used by forest managers across the region make sustainable forest management plans.?
Animal Health Component
100%
Research Effort Categories
Basic
(N/A)
Applied
100%
Developmental
(N/A)
Goals / Objectives
We will refine recommendations for improving the composition, structure, and productivity of early successional and mid-rotation stands in Maine's Acadian Forest. Specific objectives include:1) Using 15 Commercial Thinning Research Network (CTRN) research sites across the State of Maine, and building on the work of Pekol (2011), Clune (2013), and Olson et al. (2014), we will increase understanding about CT is Maine spruce-fir stands by:a) Testing how method and level of relative-density reduction of commercial thinning in older (50-70 year) and previously unthinned red spruce stands influence future productivity and stand development;b) Testing how timing-of-entry and relative-density reduction of commercial thinning in younger (30-40 years) previously precommercially thinned balsam fir stands influence future productivity and stand development;c) Testing the value of including: (1) individual-tree locations; (2) individual-tree crown and canopy attributes with respect to thinning treatment; and (3) the amount and use efficiency of intercepted light following CT when modeling the growth and survival of individual trees in the post-CT stand.d) Using results from objectives (a) to (c) to provide forest managers with specific recommendations for individual-tree selection, timing-of-entry, thinning method, and relative-density reduction when commercial thinning in spruce-fir stands; ande) Testing whether LiDAR coverage of the 15 CTRN sites can be used to accurately quantify stand conditions among CT treatments;f) Using results from above investigations to contribute data and equations for ongoing efforts by Dr. Aaron Weiskittel (UMaine) to improve the USFS Forest Vegetation Simulator (NE-FVS) used by forest managers across the region.2) Using new "third-wave" treatments installed on the CFRU Austin Pond Study in 2013-14, and building on the work of Olson et al. (2012) and Bataineh et al. (2013b,c) during the last period, we will compare silvicultural options in PCTd and non-PCTd stands by:a) Comparing initial tree and stand responses following mid-rotation commercial thinning, conifer release, and red spruce release treatments in previously precommercially thinned and unthinned stands;b) Testing whether LiDAR coverage of the study site can be used to accurately quantify stand conditions among recent harvest treatments; andc) Developing a new experiment to compare coppice hardwood management and high-yield spruce plantations as future management options for the next rotation.3) Using the Silviculture Intensity and Compositional Objective (SIComp) experiment on the Penobscot Experimental Forest and building on the recent work of Nelson et al. (2012, 2013, 2014), we will increase understanding about stand dynamics in early successional stands by:a) Comparing how tree species differing widely in shade tolerance (e.g., aspen, birch, red maple, balsam fir, and spruce) respond under varying levels of silvicultural intensity and tree species composition objectives;b) Comparing carbon accumulation (or total carbon stock) in young stands managed under varying compositional objectives and levels of energy input (human labor, pesticide, and petroleum) that have been measured during the length of study; andc) Testing whether LiDAR coverage of the SIComp site can be used to accurately quantify stand conditions among treatments.4) We will improve silvicultural approaches for improving the composition of hardwood regeneration in beech-dominated understories, and build on the work of Nelson and Wagner (2011, 2014), by:a) Remeasuring and analyzing the 10-year outcome of a controlled experiment comparing herbicide treatments designed to increase dominance of sugar maple in beech-dominated understories;b) Estimating stand-level and forest-level financial gains from increasing sugar maple composition in beech-dominated hardwood stands; andc) Identifying archetypal stand conditions where beech-dominated midstories and understories are most problematic for forest managers in northern Maine as a pilot study for a new controlled experiment.
Project Methods
The following approach will be used to accomplish each of the objectives:1)Commercial Thinning Research Network (CTRN): a) We will continue scheduled measurements of all non-PCT experimental installations on 6 sites to continue testing and refining our understanding about how CT method and level of relative-density reduction of commercial thinning in older (50-70 year) and previously unthinned red spruce stands influence productivity and stand development. Of special interest in this analysis will be comparing differences among treatments in how stand volume is distributed among diameter classes in post-CT stands.b) We will continue scheduled measurements of all previously PCTd experimental installations on 9 sites to continue testing and refining our understanding about how CT timing-of-entry and relative-density reduction of commercial thinning in younger (30-40 years) previously precommercially thinned balsam fir stands influence future productivity and stand development. Of special interest in this analysis will be comparing differences among treatments in how stand volume is distributed among diameter classes in post-CT stands.c) We will test whether individual-tree locations, individual-tree crown and canopy attributes, and intercepted light following CT can be used to model the effects of CT at the individual-tree level using individual-tree measurements from the repeated measurements over the past 10-15 years. Our focus will be in determining whether any particular individual-tree attributes can be used to improve tree selection by forest managers during CT operations in spruce-fir stands.d) We will provide forest managers with specific recommendations for individual-tree selection, timing-of-entry, thinning method, and relative-density reduction when commercial thinning in spruce-fir stands based on completion of objectives (a) to (c) above.e) We will use 6 point/m2 LiDAR data collected in 2014 on fifteen CTRN sites to determine whether LiDAR data can be used to accurately quantify stand conditions among different CT treatments.f) We will provide data from the next 5-years of CTRN scheduled measurements to Dr. Aaron Weiskittel for his efforts to improve CT-response estimations in spruce-fir stands for inclusion into the USFS Forest Vegetation Simulator (NE-FVS) used by forest managers across the region.2)Austin Pond Study:a) We will establish a new measurement cycle for the treatment plots that received CT in spring 2014 and complete these annually over the next 5 years. An initial investigation will focus on the probability of tree scarring as it is relates to CT prescription and initial stand condition at the time of harvest, as well as quantification of the residual stand conditions created by the "third wave" of treatments. Using the initial measurements during the first few years of the new study, we also will compare initial tree and stand responses following 33%, 50%, and 66% RD reductions following CT, conifer release, and red spruce release treatments in previously PCTd and non-PCTd stands.b) We will use 6 point/m2 LiDAR data collected in 2014 from the site to determine whether LiDAR data can be used to accurately quantify stand conditions among different CT treatments.c) We will use two newly established clearcut areas on the site to establish twelve 200 x 200 ft treatments plots for comparing two potential silvicultural options for the future management of northern Maine forests. Two treatments (replicated 6 times each) will be established for comparison: coppice hardwood management and high-yield spruce plantations.3)Silviculture Intensity and Compositional Objective (SIComp) Study:a) We will use decadal measurements of individual crop trees from 20 x 20 m plots to compare how naturally regenerated tree species differing widely in shade tolerance (e.g., aspen, birch, red maple, balsam fir, and spruce) have responded to 3 levels of silvicultural intensity (high, medium low) and 3 levels of tree species composition objectives (softwood, mixedwood, hardwood).b) We will use decadal measurements from five circular compositional plots to quantify carbon accumulation (or total carbon stock) in young stands managed under varying compositional objectives and various levels of energy input (human labor, pesticide, and petroleum) that have been measured for more than a decade.c) We will use 6 point/m2 LiDAR data collected in 2014 on the site to determine whether LiDAR data can be used to accurately quantify early successional stand volumes and biomass.4)Rehabilitation of Beech-Dominated Understories:a) We will measure and analyze the 10-year outcomes of a controlled experiment that includes a 3 x 4 factorial combination of glyphosate (Accord Concentrate) herbicide (0.5, 1, and 1.5 lb/ac) and Entree 5735 surfactant (0.25, 0.5, and 1% concentrations) applied to the understories of a recently shelterwood harvested stands on three study sites across northern Maine. We will assess whether the regeneration dynamics established during the three years after treatment (reported in Nelson and Wagner 2011) have persisted for the decade following treatment.b) We will use the results of objective (a) to model hardwood stand development and assess stand-level financial gains from increasing sugar maple composition in beech-dominated hardwood stands. We also will pursue a forest-level analysis of the problem using Woodstock software and theoretical forest landscapes where beech-dominated stands represent a significant portion of the stands.c) We will work with northern Maine forest landowners to locate a minimum of 20 stands that they believe represent the range of beech-dominated stand conditions that they find most difficult to manage. We will sample those stands to quantify the stand structure and composition of the overstory, midstory, and understory. Multivariate and other analytical approaches will be used to identify the range of archetypal stand conditions where beech-dominated midstories and understories are most problematic for forest managers. This pilot study will be used to develop a new experiment aimed at investigating approaches for rehabilitating beech-dominated stands following various forms of partial cutting.