This study was conducted to develop a simple volume model for the Larix kaempferi species in the Central Region of South Korea. General volume model forms were used and validated using a subset of the data collected for the L. kaempferi species. A total of 550 trees were collected in the different L. kaempferi stands through destructive sampling. The dataset was randomly divided into two: 80% for initial model development(seven volume models) and 20% for model validation. The 100% dataset was used for the final model fitting. Evaluation statistics including bias(Ē), absolute mean deviation(AMD), root mean square error(RMSE), coefficient of determination(R2), and the Akaike Information Criterion values(AIC) and weight (AICw) were used to assess performance of the different volume models. Rank analysis was employed and the first five best volume models were chosen for the model validation and final model fitting. The evaluations showed that volume model 4(V=aDBHb*Hc) had the best performance, while volume model 3(V=aDBH+bDBH2), which has a single variable, had the poorest performance.

To develop an empirical degree-day model for predicting the spring flight period of the bark beetle, Ips subelongatus Motschulsky, based on field observation, field studies were biweekly conducted in three Japanese larch (Larix kaempferi) forests in In-je, Korea from 2013 to 2014. To validate this degree-day model, we compared the model-predicted values with observed emergence data of I. subelongatus in 2015 spring at one of the sites. The flight period of over-wintering generation began on April and ended May, and flight of next generation lasted until October. The lower developmental threshold temperature (LDT) was estimated using spring emergence of I. subelongatus and field temperatures. Then a degree-day model was constructed, based on LDTs estimated from field observations data. The baseline temperature with the highest coefficient of determination was considered the LDT, and this was estimated to be 6.0℃. The explanatory power of the model was 88%. This model accurately predicted the flight of I. subelongatus in 2015 spring, as the estimated median flight dates was 1 days earlier than the corresponding observed flight date. The results of the goodness-of-fit test did not differ between observed and estimated values (ks = 0.21, P = 0.54).

The effects of thinning on community diversity of wood-boring beetles were examined in Japanese Larch (Larix kaempferi) forest in In-je, South Korea in 2013. Three study sites were selected and thinning in the plots was conducted in 2010, spring 2012, and autumn 2012, respectively. Wood-boring beetles were collected every week using the 12-unit Lindgren multi-funnel traps with pheromone lure (Ipsdienol +50/-50 40mg, Ipsenol +50/-50 40mg) from mid-April to early November. Total 5 families (Cerambycidae, Curculionidae, Dryophthoridae, Scolytidae, Platypodidae), 62 species, and 26,638 individuals were collected. Diversity indices were 2.08, 2.02 and 0.76, and evenness indices were 0.55, 0.49 and 0.19 in 2010, spring 2012 and autumn 2012 thinning area, respectively. Among wood-boring beetles, the number of species of bark and ambrosia beetles were accounted for 44.4, 41.9 and 46.3% in 2010, spring 2012 and autumn 2012 thinning area, respectively. The number of individuals of bark and ambrosia beetles were accounted for 86.9, 82.2 and 98.4% in 2010, spring 2012 and autumn 2012 thinning area, respectively. Our results showed that the density of wood-boring beetles was the highest in the most recent thinning area, suggesting that thinning timing can influenced on the abundance of bark and ambrosia beetles. Among them, Ips subelongatus, I. acuminatus, and I. sexdentatus are species that mainly attack Japanese Larch. Ips subelongatus emerged faster than others and was the most dominant species.

Forest resource development including plantation and thinning has severely influenced on the forest ecosystems. In this study, we compared differences of soil invertebrate communities between a larch planted forest and a natural deciduous forest. Soil invertebrates were collected at 6 sampling sites in the natural deciduous forest and at 9 sampling sites in the larch planted forest in June and September, 2013. Each study site was set in 1 ha and soil samples were collected using a soil core (5.5 cm diameter and 4.5 cm height). After sampling soil invertebrates, the invertebrates were extracted using Tullgren extractor for 72 hours. In total, 1,194 individuals and 22 taxa of soil invertebrates were identified in this study. Among them, Collembola was the most dominant taxa (41% of abundance). Abundance of the larch planted forest was higher two times than that of the natural deciduous forest. The results of this study provide fundamental information on soil invertebrate fauna before the forest managements. In the further study, we will examine the effects of various types of forest management on the community of soil invertebrates.

The larch hawk moth, Sphinx morio, belongs to the lepidopteran family Sphingidae that has long been studied as a family of model insects in a diverse field. In this study, we describe the complete mitochondrial genome (mitogenome) sequences of the species in terms of general genomic features and characteristic short repetitive sequences found in the A+T-rich region. The 15,299-bp long genome consisted of a typical set of genes (13 protein-coding genes, two rRNA genes and 22 tRNA genes) and one major non-coding A+T-rich region, with the typical arrangement found in Lepidoptera. The 316-bp long A+T-rich region located between srRNA and tRNAMet harbored the conserved sequence blocks that are typically found in lepidopteran insects. Additionally, the A+T-rich region of S. morio contained three characteristic repeat sequences that are rarely found in Lepidoptera: two identical 12-bp repeat, three identical 5-bp long tandem repeat, and six nearly identical 5~6 bp long repeat sequences.

[Introduction] Larix kaempferi (Larch), rich biomass in Hokkaido, is available as an inexpensive medium for mushroom production. We have previously developed a variety of Hypsizygus marmoreus with high ability to utilize larch sawdust without watering, Hm 219 (Marbure 219) with high fruit-body yield and high score of sensory evaluation, was selected. In this study, we investigated the effects of supplements to larch sawdust-based medium on taste components of fruit-bodies of Hm 219. [Materials and methods] The strain of H. marmoreus used in this study was Hm 219, the stock culture of Hokkaido Research Organization Forest Products Research Institute. Each 850 ml plastic bottle containing 540 g of larch sawdust-based substrate, was used for cultivation. Moisture content of each medium was adjusted to 61% based on the fresh weight of the mixture of solid materials. The substrate substituted with 0-40% of supplements (wheat bran, soybean curd residue and soybean shell) for rice bran as a nutrient, were used for cultivation. Cultivation was conducted by the standard procedure reported earlier (Harada et al., 2004). The harvested fruit-bodies were freeze-dried to determine the chemical composition. Soluble sugars, free amino acids and 5’-nucleotides were extracted with hot water from freeze-dried powder. These soluble components were determined by using HPLC. [Results] As a result, fruit-body yields on the substrate substituted with 20% of soybean shell for rice bran as a nutrient, were about 20% higher than those on the substrate with rice bran only. According to the replacement rate of soybean curd residue increasing , morphological quality of fruit-body tended to decline. As major free amino acids in fruit-body, monosodium glutamate-like (MSG-like) components which gave the umami taste, including aspartic acid and glutamic acid, and sweet components including alanine, threonine and serine were detected. As flavor 5’-nucleotides, GMP and IMP were found. In fruit-body of H. marmoreus, with respect to major soluble sugars, mannitol and trehalose were mainly contained. Each taste component content indicated differences among the different supplements to larch sawdust-based medium. The equivalent umami concentration (EUC ) is the concentration of MSG equivalent to the umami intensity of that given by the mixture of MSG and the 5’-nucleotide (Lee, Yu-Ling et al., 2009). The EUC value in a cultivation condition was more 15% higher than that of control condition. [References] Harada, A. et al. (2004) Effects of strain and cultivation medium on the chemical composition of the taste components in fruit-body of Hypsizygus marmoreus. Food Chemistry, 84, 265-270. Lee, Yu-Ling et al. (2009) Composition and non-volatile components of Hypsizygus marmoreus, LWT- Food Science and Technology, 42, 594-598.

There are many related studies; however, almost all of them focus on higher taxonomic tendencies, ignoring a difference in the reaction for each species. In this study, we measured relative basal area (RBA) as the index for invasion of broad-leaved trees into eight Larch plantations, and investigated the relationship between RBA and composition and abundance of oribatid mites community. As a result, we found 49 families, 60genus, 89 species, 24,368 adult and larvae and nymphs, 56,364. The degree of invasion of broad-leaved trees did not affect significantly total abundance and number of species for oribatid mites observed. While, those measurements significantly correlated with the total amount of litter, including conifer and broad-leaves. We also found that there are many oribatid mite species showing habitat preference relating to a kind of litter.