Ectomycorrhizal development in a Pinus thunbergii stand in relation to location on a slope and effect on tree mortality from pine wilt disease

Abstract

The relationship between ectomycorrhizal development and mortality from pine wilt disease was studied in an artificial Pinus thunbergii Parl. stand on a slope. The development of ectomycorrhizae and the survival of the trees showed the same tendency, which suggests a correlation between mycorrhizal development and resistance to pine wilt disease. The development of pine roots and mycorrhizae was greater in the upper part of the slope. The ratio of mycorrhizae to the total of mycorrhizae and fine taproots was also higher in the upper part of the slope. Tree mortality was clearly biased and more trees survived in the upper part of the slope than in the middle and the lower parts. There was no significant difference between the upper and the lower part of the slope in the number of feeding wounds made by the pine sawyer beetle, which demonstrates the opportunity of infection with this disease. There was no clear correlation between the development of mycorrhizae and the composition of the soil substrate such as total carbon, nitrogen, and phosphorus. The abundant mycorrhizae in the upper part of the slope, which mitigate drought stress, may also have decreased the rate of tree mortality.

Effects of pine wilt disease invasion on soil properties and Masson pine forest communities in the Three Gorges reservoir region, China

“…1999), light conditions (Mabuhay and Nakagoshi 2012), soil water content (Suzuki and Kiyohara 1978; Miki et al. 2001; Akema and Futai 2005), and soil physicochemical properties (Kim et al. 2010; Mabuhay and Nakagoshi 2012).…”

Ectomycorrhizae and ectomycorrhizal fungal fruit bodies in pine stands differentially damaged by pine wilt disease

“…Thus, the effects of soil conditions should be considered to understand the relationship between ectomycorrhizal association and pine wilt damage. Neither Akema and Futai (2005) nor Ichihara et al (2001) reported the ectomycorrhizal community structure on pine roots. Kikuchi et al (1991) compared the different effects of ectomycorrhizal species on pine resistance, but they observed only two fungal species.…”

“…Akema and Futai (2005) reported a difference in soil moisture between the upper and lower slopes. Soil conditions such as soil moisture can infl uence ectomycorrhizal association (Slankis 1974).…”

“…Regarding the relationship between ectomycorrhizal abundance and pine wilt damage, Akema and Futai (2005) found that pine wilt damage was lighter and the rate of ectomycorrhizal root tips was higher on upper slopes than lower slopes. Thus, ectomycorrhizal abundance is thought to be related to pine wilt damage, but the causal association is not clear.…”

The Impact of the 1998 Forest Fire on Ectomycorrhizae of Dipterocarp Trees and their Recovery in Tropical Rain Forests of East Kalimantan, Indonesia

“…Forest fire often kills host trees and this is fatal to ectomycorrhizal fungi because they are virtually obligate symbionts. However, even if the host trees survived, mycorrhizae can be seriously damaged by the burning of the litter layer and consequent heating of top soil because mycorrhizae distribute mainly in the top soil 3 . In dipterocarp trees, the loss of the functions of ectomycorrhizae may be a very serious problem to the recovery from the forest fire, because they largely depend on mycorrhizae for the function of the roots.…”