Potential distribution of pine wilt disease under future climate change scenarios

Abstract

Pine wilt disease (PWD) constitutes a serious threat to pine forests. Since development depends on temperature and drought, there is a concern that future climate change could lead to the spread of PWD infections. We evaluated the risk of PWD in 21 susceptible Pinus species on a global scale. The MB index, which represents the sum of the difference between the mean monthly temperature and 15 when the mean monthly temperatures exceeds 15°C, was used to determine current and future regions vulnerable to PWD (MB ≥ 22). For future climate conditions, we compared the difference in PWD risks among four different representative concentration pathways (RCPs 2.6, 4.5, 6.0, and 8.5) and two time periods (2050s and 2070s). We also evaluated the impact of climate change on habitat suitability for each Pinus species using species distribution models. The findings were then integrated and the potential risk of PWD spread under climate change was discussed. Within the natural Pinus distribution area, southern parts of North America, Europe, and Asia were categorized as vulnerable regions (MB ≥ 22; 16% of the total Pinus distribution area). Representative provinces in which PWD has been reported at least once overlapped with the vulnerable regions. All RCP scenarios showed expansion of vulnerable regions in northern parts of Europe, Asia, and North America under future climate conditions. By the 2070s, under RCP 8.5, an estimated increase in the area of vulnerable regions to approximately 50% of the total Pinus distribution area was revealed. In addition, the habitat conditions of a large portion of the Pinus distribution areas in Europe and Asia were deemed unsuitable by the 2070s under RCP 8.5. Approximately 40% of these regions overlapped with regions deemed vulnerable to PWD, suggesting that Pinus forests in these areas are at risk of serious damage due to habitat shifts and spread of PWD.

Relationship between Pine Wilt Disease Outbreaks and Climatic Variables in the Three Gorges Reservoir Region

“…Any slight change in microclimatic conditions can alter the interactions among B. xylophilus, vector insects, and host trees, which may add more complexity to the PWD system [10,13,50]. Future climate change could potentially lead to more serious PWD-related global Pinus forest resource reduction and habitat degradation [4,51]. Previous research has predicted that the area suitable for development and spread of PWD will increase.…”

Changes in Major Insect Pests of Pine Forests in Korea Over the Last 50 Years

“…Choi et al [46] estimated the annual dispersal distance in South Korea to be 0.37 km, based on the annual changes of areas damaged by PWD in the early stages of invasion, and the annual dispersal distances were less than 1.0 km in most (88.8%) of damaged areas; they also showed that "jumping" was the dominant dispersal method in the early stages of the invasion, while later dispersal was due to the expansion of existing colonies. Dispersal speed increased with increasing human population density, suggesting human-mediated dispersal [66,67].…”

“…The effect of temperature, precipitation and landscape features was evaluated on the level of risk of PWD occurrence [69]. A MB (Monochamus/Bursaphelenchus) index was developed [78] by summing the difference between the monthly average temperature and 15 • C when the monthly average temperatures exceeds 15 • C for one year [67]. The index displayed large differences between the PWD occurrence area in the field and the area predicted with the index in Korea, but the predictability of the index was improved by the modification of the threshold temperature [79].…”

Invasive Tree Pests Devastate Ecosystems—A Proposed New Response Framework

“…This veritable reaper's list is long indeed and plays out similarly across the globe, whether it be pine wilt nematode first in Asia and now Europe (Hirata et al, 2017), red turpentine beetle in China (Sun et al, 2013), or ash dieback in Europe (Mitchell et al, 2014). In addition to lost cultural significance and aesthetic value of native trees, their decline and death have staggering economic impacts.…”