<oai_dc:dc xmlns:dc="http://purl.org/dc/elements/1.1/" xmlns:oai_dc="http://www.openarchives.org/OAI/2.0/oai_dc/" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.openarchives.org/OAI/2.0/oai_dc/ http://www.openarchives.org/OAI/2.0/oai_dc.xsd">
  <dc:creator>Lundström, Tor</dc:creator>
  <dc:creator>Jonsson, Martin J.</dc:creator>
  <dc:creator>Kalberer, M.</dc:creator>
  <dc:date>2007-09-20</dc:date>
  <dc:description xmlns:ns0="xml" ns0:lang="en">The reactions of trees to wind, rockfall, and snow and debris flow depend largely on  how strong and deformable their anchorage in the soil is. Here, the resistive turning  moment &lt;i&gt;M&lt;/i&gt; of the root–soil system as a function of the rotation &lt;i&gt;ϕ&lt;/i&gt; at the  stem base plays the major role. &lt;i&gt;M&lt;/i&gt;(&lt;i&gt;ϕ&lt;/i&gt;) describes the behavior of the root– soil system when subject to rotational moment, with the maximum &lt;i&gt;M&lt;/i&gt;(&lt;i&gt;ϕ&lt;/i&gt;)  indicating the anchorage strength &lt;i&gt;M&lt;/i&gt; &lt;sub&gt;a&lt;/sub&gt; of the tree. We assessed  &lt;i&gt;M&lt;/i&gt;(&lt;i&gt;ϕ&lt;/i&gt;) of 66 Norway spruce (&lt;i&gt;Picea abies&lt;/i&gt; L. Karst) by pulling them  over with a winch. These 45- to 170-year-old trees grew at sites of low and high  elevation, with a diameter at breast height DBH = 14–69 cm and a height &lt;i&gt;H&lt;/i&gt; =  9–42 m. &lt;i&gt;M&lt;/i&gt;(&lt;i&gt;ϕ&lt;/i&gt;) displayed a strong nonlinear behavior. &lt;i&gt;M&lt;/i&gt;  &lt;sub&gt;a&lt;/sub&gt; was reached at a lower &lt;i&gt;ϕ&lt;/i&gt; for large trees than for small trees.  Thus overhanging tree weight contributed less to &lt;i&gt;M&lt;/i&gt; &lt;sub&gt;a&lt;/sub&gt; for the large  trees. Overturning also occurred at a lower &lt;i&gt;ϕ&lt;/i&gt; for the large trees. These  observations show that the rotational ductility of the root–soil system is higher for  small trees. &lt;i&gt;M&lt;/i&gt; &lt;sub&gt;a&lt;/sub&gt; could be described by four monovariate linear  regression equations of tree weight, stem weight, stem volume and DBH ² ·&lt;i&gt;H&lt;/i&gt;  (0.80 &lt; &lt;i&gt;R&lt;/i&gt; ² &lt; 0.95), and &lt;i&gt;ϕ&lt;/i&gt; at &lt;i&gt;M&lt;/i&gt; &lt;sub&gt;a&lt;/sub&gt;, &lt;i&gt;ϕ&lt;/i&gt;  &lt;sub&gt;a&lt;/sub&gt;, by a power law of DBH²·&lt;i&gt;H&lt;/i&gt; (&lt;i&gt;R&lt;/i&gt; ² = 0.85). We found  significantly higher &lt;i&gt;M&lt;/i&gt; &lt;sub&gt;a&lt;/sub&gt; for the low-elevation spruces than for the  high-elevation spruces, which were more shallowly anchored, but no significant  difference in &lt;i&gt;ϕ&lt;/i&gt; &lt;sub&gt;a&lt;/sub&gt;. The 66 curves of &lt;i&gt;M&lt;/i&gt;(&lt;i&gt;ϕ&lt;/i&gt;), normalized  (&lt;sub&gt;n&lt;/sub&gt;) by &lt;i&gt;M&lt;/i&gt; &lt;sub&gt;a&lt;/sub&gt; in &lt;i&gt;M&lt;/i&gt;-direction and by &lt;i&gt;ϕ&lt;/i&gt;  &lt;sub&gt;a&lt;/sub&gt; in &lt;i&gt;ϕ&lt;/i&gt;-direction, yielded one characteristic average curve: &lt;span  class="overline"&gt;&lt;span class="cmmi-10"&gt;M&lt;/span&gt;&lt;/span&gt;&lt;sub&gt;n&lt;/sub&gt; (ϕ&lt;sub&gt;n&lt;/sub&gt;) M¯nϕn . Using this average curve and the predictions of M a and ϕ  a, it is shown that M(ϕ) and the curves associated with M(ϕ) can be predicted with a  relative standard error ≤25%. The parameterization of M(ϕ) by tree size and weight is  novel and provides useful information for predicting with finite-element computer  models how trees will react to natural hazards.</dc:description>
  <dc:format>application/pdf</dc:format>
  <dc:identifier>https://folia.unifr.ch/global/documents/300523</dc:identifier>
  <dc:identifier>https://folia.unifr.ch/documents/300523/files/11104_2007_Article_9386.pdf</dc:identifier>
  <dc:language>eng</dc:language>
  <dc:relation>info:eu-repo/semantics/altIdentifier/doi/10.1007/s11104-007-9386-2</dc:relation>
  <dc:rights>info:eu-repo/semantics/openAccess</dc:rights>
  <dc:rights>License undefined</dc:rights>
  <dc:source>Plant and Soil. - 2007, vol. 300, no. 1-2, p. 35-49</dc:source>
  <dc:subject xmlns:ns1="xml" ns1:lang="en">allometry</dc:subject>
  <dc:subject xmlns:ns2="xml" ns2:lang="en">energy absorption capacity</dc:subject>
  <dc:subject xmlns:ns3="xml" ns3:lang="en">protective forest</dc:subject>
  <dc:subject xmlns:ns4="xml" ns4:lang="en">mechanical modeling</dc:subject>
  <dc:subject xmlns:ns5="xml" ns5:lang="en">tree structure</dc:subject>
  <dc:subject xmlns:ns6="xml" ns6:lang="en">uprooting process</dc:subject>
  <dc:subject>info:eu-repo/classification/udc/57</dc:subject>
  <dc:title xmlns:ns7="xml" ns7:lang="en">The root-soil system of Norway spruce subjected to turning moment: resistance as a function of rotation</dc:title>
  <dc:type>http://purl.org/coar/resource_type/c_6501</dc:type>
</oai_dc:dc>