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The ambrosia beetle, Platypus kortjoensis (Murayama), vectors the Korean oak wilt (KOW) pathogen, Raffaelea quercus-mongolicae K.H. Kim, Y.J. Choi, & H.D. Shin, in Korea, which is highly lethal to Mongolian oak, Quercus mongolica Fisch., and is considered a major threat to forest ecosystem health. We characterized the attack pattern of P. koryoensis along the lower trunk of 240 Mongolian oaks in relation to tree decline symptoms on Mt. Uam in Gyeonggi-Do Province, Korea during June-July 2009. For each tree, we recorded diameter at breast height (dbh) (DBH) and P. kortdoensis entrance hole density at two heights along the lower trunk (near groundline and at 1.5 m above groundline) and on opposite sides (downslope side and upslope side). Trees were assigned to one of three dieback classes: 1 ) apparently healthy, no or practically no wilted foliage, and no obvious platypodine frass near the base of the tree; 2) no or only partial wilting with obvious frass near the base of the tree; and 3) apparently recently killed by KOW with all foliage wilted and mostly retained with obvious frass near the base of the tree. As dieback class increased from 1 to 3, P. koryoeusis entrance hole density increased at all four trunk locations. Attack density was highest on the downslope side of the trunk near groundline, and principal component analysis indicated that this trunk location was the best indicator of tree dieback. In addition, DBH tended to increase with dieback class suggesting that larger trees were infested first. [ABSTRACT FROM AUTHOR]

Fauna assemblages reflect their habitat relating to ecological function in an ecosystem. The functional groups are concerned with how a resource is processed by different species to provide a specific ecosystem service or function. We elucidated seasonal changes of coleopteran functional groups in forests, and evaluated their ecological roles related to available food resources. Coleopteran communities were collected weekly or biweekly using Malaise traps at nine study sites in Japanese red pine forests in Korea from late June to September 2005. Compositions of the functional groups were compared at the different sites and at sampling times with respect to taxa richness and abundance. Cluster analysis and non-metric multidimensional scaling were used to characterize spatial and temporal changes of functional groups. Herbivores and dead/live wood feeders regulating primary production in the pine forests were the dominant coleopteran groups in July, followed by detritivores and predators that dominated from July to August, resulting from the accumulation of detritus. Then, fungivores became dominant due to increased fungal biomass in the forest. Seasonal changes of coleopteran functional groups shifted from regulators of primary production to regulators of decomposition, reflecting their available food resources. In addition, abundance of detritivores and predators were dependent on total abundance of coleopterans, suggesting that these two groups reflect their habitat condition. [ABSTRACT FROM AUTHOR]