{"id":3199,"date":"2019-02-13T09:00:14","date_gmt":"2019-02-13T08:00:14","guid":{"rendered":"https:\/\/ist.blogs.inra.fr\/afs\/?p=3199"},"modified":"2019-02-08T16:14:21","modified_gmt":"2019-02-08T15:14:21","slug":"the-effect-of-thinning-on-mechanical-properties-of-douglas-fir-norway-spruce-and-sitka-spruce","status":"publish","type":"post","link":"https:\/\/ist.blogs.inrae.fr\/afs\/2019\/02\/13\/the-effect-of-thinning-on-mechanical-properties-of-douglas-fir-norway-spruce-and-sitka-spruce\/","title":{"rendered":"The effect of thinning on mechanical properties of Douglas fir, Norway spruce, and Sitka spruce"},"content":{"rendered":"<script type='text\/javascript' src='https:\/\/d1bxh8uas1mnw7.cloudfront.net\/assets\/embed.js'><\/script><p align=\"justify\">Thinning affects negatively the quality of sawn timber of Douglas fir, Norway spruce, and Sitka spruce. The effect was confirmed in structural-sized boards and small clear samples, and on standing trees using longitudinal velocity. The loss of quality across the three species due to thinning rarely exceeds 20% and is in most cases smaller than 5%.<\/p>\n<p align=\"justify\"><strong>Context<\/strong> The relationship between silvicultural management and the quality of timber produced is not entirely elucidated.<br \/>\n<strong>Aims<\/strong> The effects of thinning on structural grade-determining properties of wood (elastic modulus, bending strength and density) were studied on Douglas fir (<em>Pseudotsuga menziesii<\/em> (Mirb.) Franco), Norway spruce (<em>Picea abies<\/em> (L.) H. Karst), and Sitka spruce (<em>Picea sitchensis<\/em> (Bong.) Carr)).<br \/>\n<strong>Methods<\/strong> Acoustic velocity was measured in a total of 487 trees and their crown social status was recorded. Sixty trees were selected and cut into structural-sized boards (N\u2009=\u20091343). The amount of knots in each board was quantified using the grading machine GoldenEye702. All boards were destructively tested in four-point bending, after which a small clear specimen was cut from each board and again tested in bending (N\u2009=\u20091303). Specific stiffness and specific strength were used to estimate the size of the effect accounting for differing influence of thinning across the before-mentioned properties.<br \/>\n<strong>Results<\/strong> Thinning reduces all three properties with the likelihood and magnitude of the effect varying between species. The loss of quality due to thinning rarely exceeds 20% and is in most cases smaller than 5%. The effect of thinning and its size were also confirmed on the full sample of trees by using longitudinal velocity.<br \/>\n<strong>Conclusion<\/strong> The results give a clearer idea of what the trade-offs are between timber quality and silvicultural management.<\/p>\n<p><strong>Keywords<\/strong><br \/>\nThinning, Wood quality, Softwoods, Bayesian analysis<\/p>\n<div class='altmetric-embed' data-badge-type='donut' data-doi='10.1007\/s13595-018-0787-6'  style='float: right; ' ><\/div>\n<p><strong>Publication<\/strong><br \/>\nKrajnc, L., Farrelly, N. &amp; Harte, A.M. Annals of Forest Science (2019) 76: 3. https:\/\/doi.org\/10.1007\/s13595-018-0787-6<\/p>\n<p>For the read-only version of the full text: https:\/\/rdcu.be\/blPRo<\/p>\n<p align=\"justify\"><strong>Data availability<\/strong><br \/>\nThe datasets generated during and\/or analyzed during the current study are available from the corresponding author on reasonable request.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Thinning affects negatively the quality of sawn timber of Douglas fir, Norway spruce, and Sitka spruce. The effect was confirmed in structural-sized boards and small clear samples, and on standing trees using longitudinal velocity. The loss of quality across the three species due to thinning rarely exceeds 20% and is in most cases smaller than [&hellip;]<\/p>\n","protected":false},"author":106,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[14,15],"tags":[],"class_list":["post-3199","post","type-post","status-publish","format-standard","hentry","category-article-type","category-research-paper","cat-14-id","cat-15-id"],"_links":{"self":[{"href":"https:\/\/ist.blogs.inrae.fr\/afs\/wp-json\/wp\/v2\/posts\/3199","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/ist.blogs.inrae.fr\/afs\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/ist.blogs.inrae.fr\/afs\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/ist.blogs.inrae.fr\/afs\/wp-json\/wp\/v2\/users\/106"}],"replies":[{"embeddable":true,"href":"https:\/\/ist.blogs.inrae.fr\/afs\/wp-json\/wp\/v2\/comments?post=3199"}],"version-history":[{"count":0,"href":"https:\/\/ist.blogs.inrae.fr\/afs\/wp-json\/wp\/v2\/posts\/3199\/revisions"}],"wp:attachment":[{"href":"https:\/\/ist.blogs.inrae.fr\/afs\/wp-json\/wp\/v2\/media?parent=3199"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/ist.blogs.inrae.fr\/afs\/wp-json\/wp\/v2\/categories?post=3199"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/ist.blogs.inrae.fr\/afs\/wp-json\/wp\/v2\/tags?post=3199"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}