Target Tailored Forest Damage Inventory (TFDI) - Damage by bark beetles on Norway spruce in the county of Västernorrland 2013

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 2013 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. 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. Included plots within the sample was older thinning forest and final felling mature forest consisting of at least 7/10 spruce and a lesser proportion of forest with lesser share of spruce or younger thinning forest. 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. The inventory was carried out in the same way as in 2011 and 2012, but with the addition that damaged wind-felled trees were included. During 2013 also the variable Edge time was introduced, i. e. when a stand edge within 25 m from plot center occurred. In total 93 plots and 330 trees and 118 wind-felled trees was measured.

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, wind thrown, 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. Show less..