Effects of log length on Polygraphus proximus attack
Abstract
Polygraphus proximus Blandford (Coleoptera: Curculionidae: Scolytinae), a non-aggressive bark beetle, has caused mortality of Abies spp. in Western Siberia, Central Asia, European Russia as well as Japan. Removing dead trees (i.e. salvage logging) and thinning stands are considered one of the best practices to reduce the risk of bark beetle outbreaks. However, salvaging or removing dead and thinned trees requires significant effort. Thus, to determine whether cutting trees shorter would reduce P. proximus infestation, we exposed A. sachalinensis logs of various lengths on the ground in a forest stand. The attack density of P. proximus significantly decreased with shorter log lengths. It can be concluded that cutting into short logs and leaving them on the ground are effective practices to reduce the chance of P. proximus outbreaks after natural disturbances and thinning.
README: Effects of log length on Polygrapus proximus attack
This dataset comprises one "G.csv" file.
Description of the Data and file structure
- Description: This file shows the result of the experiments to determine the effects of log length (10 cm, 20 cm, 40 cm, 60 cm, and 80cm) on the attack density of the bark beetle Polygraphus proximus.
Variables:
- "tree": The IDs of the trees from which logs were obtained.
- "logid": The IDs of the logs (bolts) used in the experiments.
- "l": length of the logs (cm).
- "c": The circumferences (cm) of the logs (= circumferences at both cut-ends and the middle/3).
- "area": length of the logs (l) * The circumferences of the logs (c).
- "gallery": Number of mother galleries under the bark. Same as the number of entrance holes by Polygraphus proximus.
- "dens": Density of the entrance holes (= "gallery" / "area").