Abstract
Root rots are considered the most important forest diseases in Estonia, causing serious concern in forest management. The majority of trees infected by forest pathogens lack easily-detectable visual symptoms, making it difficult to detect decay in a tree. We assessed the general health condition of visually healthy trees in intensively managed Norway spruce (Picea abies L. Karst.) and Scots pine (Pinus sylvestris L.) stands with resistography in order to identify trees infected by root rot. We found that 8.0% of Norway spruces and 1.6% of Scots pines had well-developed internal decay on the root collar regardless of having no external symptoms of root rot. Visually healthy trees growing on permanent forest land experienced more decay than trees growing on former agricultural land. The radial proportion of decay of damaged trees was 61% in Norway spruces and 35% in Scots pines. The results suggest that resistography can be used as a reliable method for tree vitality assessment.
Highlights
Modelling of forest stand dynamics depends on growth and mortality predictions of single trees.Tree vitality is often assessed visually in the course of forest inventories as an important indicator of forest condition [1]
The aims of this paper are (1) to study how often visually healthy trees in managed stands are infected by root diseases which cause internal decay; (2) to quantify how much the diseases influence tree growth; and (3) to assess how the incidence of a root rot in a tree depends on the former land use and on the main tree species in a stand
Norway spruces were significantly more often decayed than Scots pines (p = 0.035)
Summary
Tree vitality is often assessed visually in the course of forest inventories as an important indicator of forest condition [1]. Visual signs, including extraordinary leaf or needle loss of a tree and noticeable fruit bodies of fungi, may indicate problems with tree vitality, but often the symptoms of stem or root rot are difficult or impossible to detect visually [2,3]. Tree vitality is usually under-examined in forest inventories, as the use of more precise methods is labour-intensive and may be destructive to the examined trees. Errors in assessment of tree vitality result in bias in predicting forest stand dynamics by assessing a higher probability of tree survival and higher growth rates of unhealthy trees than warranted
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
