Analysis on Long-Distance Dispersal Characteristics of Pine Wilt Disease using Network Analysis for Conservation Planning

Abstract:

Pine wilt is an insect-vectored deadly disease caused by the pinewood nematode (PWN; Bursaphelenhcus xylophilus). In the Republic of Korea, after its first occurrence in Busan in 1988, it diffused at an extremely rapid rate and became a national-scale problem. This is due to the fact that pine sawyer, which harbors PWN as a host, often moves along the road being clanged on the moving vehicle, leading to long-distance dispersal(LDD) of PWD. This certain trait of dispersal has made numerous attempts to control the dispersal futile. The main objective of this study is to analyze the relationship between pine wilt disease(PWD) dispersal and anthropogenic factors and suggest a suitable network-based conservation plan in a spatially-explicit way. Dispersal can be divided into short and long distance dispersal depending on the movement pattern of a vector. Focusing on the LDD, the relationship between the dispersal and anthropogenic factors, such as road, railway, and trail, is scrutinized and integrated into the network. In the network, nodes are defined as the spatial centroid of habitat patch, each containing dispersal-related environmental attributes such as forest type, size, trail and settlement density. Links are connected if network distance between two patches is less than maximum dispersal capacity. A feasible PWD control plan is created using various network properties such as betweenness and cutnode. This study has a meaning in that insight on PWD control plan is produced using a network model that incorporated the effect of anthropogenic factors. It could act as a guide to indicate where to concentrate control activity in order to stop further dispersal to unharmed region. This method can be applied to control other invasive species in the developed city.

This work is supported by Korea Environment Industry & Technology Institute (KEITI) through Climate Change R&D Program, funded by Korea Ministry of Environment (MOE) (2018001310002).

Keyword: pine wilt disease, long-distance dispersal, network analysis, conservation plan