Next Article in Journal
Response of Black Ash Wetland Gaseous Soil Carbon Fluxes to a Simulated Emerald Ash Borer Infestation
Next Article in Special Issue
Impact of Tree Growth Rate on the Mechanical Properties of Douglas Fir Lumber in Belgium
Previous Article in Journal
Joint Control of Net Primary Productivity by Climate and Soil Nitrogen in the Forests of Eastern China
Previous Article in Special Issue
Adverse Genetic Correlations and Impacts of Silviculture Involving Wood Properties: Analysis of Issues for Radiata Pine
Open AccessFeature PaperArticle

Effects of Vegetation Management on Wood Properties and Plant Water Relations of Four Conifer Species in the Pacific Northwest of the USA

1
Laboratory of Wood Technology, Ghent University, 9000 Ghent, Belgium
2
Department of Forest Engineering, Resources and Management, Oregon State University, Corvallis, OR 97331, USA
3
Department of Wood Science and Engineering, Oregon State University, Corvallis, OR 97331, USA
*
Author to whom correspondence should be addressed.
Forests 2018, 9(6), 323; https://doi.org/10.3390/f9060323
Received: 5 May 2018 / Revised: 23 May 2018 / Accepted: 31 May 2018 / Published: 4 June 2018
(This article belongs to the Special Issue Wood Property Responses to Silvicultural Treatments)
In plantation forests, competition from unwanted vegetation may reduce survival and negatively impact tree growth. The goal of this study was to examine the influence of vegetation management treatments on plant water relations and wood properties. Control trees (no treatment) were compared to trees subjected to post-planting competing vegetation control for five consecutive years after planting. Four conifer species (Douglas-fir, western hemlock, western redcedar, and grand fir) were studied on two different sites in western Oregon, USA. Carbon isotope (13C) analysis was used to study intrinsic water use efficiency (iWUE) and X-ray densitometry was used to measure specific gravity, ring width, and latewood percent. We found a significant interaction between vegetation management treatment and wood ring (growing season) in iWUE for Douglas-fir. There was little effect of vegetation management treatment on ring specific gravity for all species. Only western redcedar growing at a central Coast Range site showed increased ring specific gravity under sustained competing vegetation control. When growing under conditions of sustained control of competing vegetation, western redcedar at a central Coast Range site had a significant increase in earlywood specific gravity, while Douglas-fir at a Cascade Foothills site had a significant decrease in latewood specific gravity. Western redcedar and grand fir had a significant interaction-effect on its latewood percentage, with treatment trees having a higher latewood percentage than control trees after ring 8. Further, Douglas-fir and western hemlock had a significant increase in ring, earlywood, and latewood area with treatment, and grand fir had a significant interaction-effect of treatment × ring for ring, earlywood, and latewood area. This study indicates that, for conifer trees growing under sustained vegetation control, growth gains could be achieved without compromising wood properties. However, if harvested at a target diameter, these trees will have a larger proportion of low quality corewood compared to trees from conventionally managed stands. View Full-Text
Keywords: competing vegetation control; intensive silviculture; wood specific gravity; carbon isotope discrimination: water use efficiency; Douglas-fir; grand fir; western hemlock; western redcedar competing vegetation control; intensive silviculture; wood specific gravity; carbon isotope discrimination: water use efficiency; Douglas-fir; grand fir; western hemlock; western redcedar
Show Figures

Figure 1

MDPI and ACS Style

Aernouts, J.; Gonzalez-Benecke, C.A.; Schimleck, L.R. Effects of Vegetation Management on Wood Properties and Plant Water Relations of Four Conifer Species in the Pacific Northwest of the USA. Forests 2018, 9, 323.

Show more citation formats Show less citations formats
Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Article Access Map by Country/Region

1
Back to TopTop