Target Tailored Forest Damage Inventory (TFDI) - Damage by bark beetles on Norway spruce in the county of Västernorrland and eastern Jämtland 2014

Inventories of forest damage are carried out within the Swedish University of Agricultural Sciences (SLU) Forests programme. An annual monitoring of the most important sources of forest damage is carried out by the Swedish National Forest inventory (NFI). Although the Swedish NFI is an objective and uniform inventory of forest damage in Swedish forests at national and regional scales, less common or less widespread occurrences of forests pests and pathogens are difficult to survey solely through large-scale monitoring programmes. There is a need for complementary inventories to facilitate timely delivery of relevant information. Thus Target-tailored forest damage inventories (TFDI) aiming at providing data for operational decisions making at local level, and linked to specific damage events were introduced. TFDI’s are developed to give rapid response to requested information of specific damage outbreaks. The TFDIs are carried out in limited and concentrated samples, with flexible but robust methods and design. The data collected in the TFDI shall also be of such quality that it can be useful in research. During 2014 TFDI carried out a sample inventory of the volume Norway spruce (Picea abies) damage by bark beetles, Four-eyed spruce bark beetle (Polygrapus poligraphus) and/or European spruce bark beetle (Ips typographus) in older spruce forest in the county of Västernorrland and in eastern Jämtland (township of Bräcke, Ragunda and Östersund). The reason for the geographical expansion in 2014 including Jämtland compare to the previous years was due to the severe winter storms in 2013, which felled a large amount of forest. The inventory included both standing and wind-felled trees. The purpose of the inventory was to estimate the volume Norway spruce damage by the given bark beetles, but also to highlight geographical distribution and the appearance of the damage in different forest sites. The inventory was stratified by an objective sample of all the National Forest Inventory permanent sample plots in the county of Västernorrland and eastern Jämtland. Included plots within the sample was all older thinning forest and final felling mature forest consisting of at least 7/10 proportion of spruce and 25 % of forest in the same stage consisting of 3 to 6/10 proportion of spruce and 10 % of younger thinning forest consisting of a least 3/10 proportion of spruce. The radii of sample plots use for the damage inventory was 25 m. Diameter at breast height was measured on damage trees and wind-felled trees. Diameter on stump from cut trees with fresh damage was measured. Furthermore species of bark beetle and age of damage was recorded. Height and volume are estimated only for trees infested during present (0) season. The inventory was carried out in the same way as in 2011, 2012 and 2013. Wind-felled trees were included as in 2013 which comprises both wind-felled trees newly infested (season 0) with bark beetles and fresh wind-felled trees not infested with bark beetle. The dataset consist at plot level of 183 rows with 23 column, at tree level of 610 rows with 12 columns and at wind-felled tree level of 302 rows with 12 columns. Some assessed and used variables: At sample plot level: Plot area measured The proportion of spruce at the sample plot Maturity class At tree level: Is the tree dead or alive? Position of tree – standing, stump Diameter at breast height Which species of bark beetle has attacked the tree? Which season did the damage occur? Tree volume At wind-felled tree level: Diameter at breast height Is the tree infested by bark beetle? Which species of bark beetle has attacked the tree? Which season did the tree fell? Tree volume See the document "Data_description" for more detailed information. As additional documentation, field instructions for the inventories are also provided, both for the specific inventory and for the National Forest Inventory (NFI). An English version of the National Forest Inventory field instruction is available for year 2021 only, which is why this is included here.