Earticle

American bullfrogs (Lithobates catesbeianus), which are native to the eastern United States, have been widely introduced to other parts of the world through food and pet trade. These include parts of North, Central, and South America, Western Europe, and parts of Asia. In many of these regions, they have become invasive by predating or outcompeting native animals. This is true in the Republic of Korea. Because of the potentially damaging impact on ecosystems where this species is not native, it is pertinent to delineate through habitat suitability models where it is most likely to find suitable habitat outside of its native range in order to effectively prevent future outbreaks. Here, we use presence points available through the Global Biodiversity Information Facility (GBIF) along with mixed method habitat suitability modelling to determine areas of highest suitability and areas most at risk of invasion. We first ran ecological niche factor analysis (ENFA) of bioclimatic factors on global and local (Korean) grids representing presence and pseudo-absence points. The original and ENFA modelled presence-pseudoabsence points were then fed separately into random forest algorithms using the same bioclimatic variables. The two results were subsequently averaged to indicate areas at greatest risk of invasion; points with a value > 0.5 were considered risk areas. The model for South Korea was then combined with habitat factors including elevation, vegetation, and landscape type to represent suitable habitat. The final global model showed that globally, the highest risk areas are located in Western North American, South America, Western Europe, parts of Africa, Japan, Southeast Asia, Western Australia, and New Zealand. Within these areas, L. catesbeianus already occurs at high levels in Western North America and moderate levels in South America, Western Europe, and Japan; the species also has limited occurrences in Southeast Asia. In South Korea, the model shows highest suitability in the western and southeastern parts of the country, with suitable habitat located at lower elevations and in areas with higher wetness indices.

The American Bullfrog, Lithobates catesbeianus, has been described as a vector and reservoir of chytrid fungus, Batrachochytrium dendrobatidis (Bd), which has devastated many amphibian populations around the world. However, the prevalence of Bd carried by L. catesbeianus on local amphibian populations is infrequently tested. In the Republic of Korea, the introduced L. catesbeianus is known to be a predator of local amphibian species, including the endangered Dryophytes suweonensis and the ubiquitous D. japonicus. In this study we showed that the presence of L. catesbeianus results in a significant increase in Bd prevalence in the two treefrog species. Furthermore, Bd prevalence was four times higher in the endangered D. suweonensis than in the common D. japonicus for all 37 sites tested. In addition, the sites with L. catesbeianus were striking by the absence of D. suweonensisin their immediate vicinity. Although the factors for the negative impact of L. catesbeianus on D. suweonensis population cannot yet be established, L. catesbeianus-borne chytrid fungus is likely one of the causes for D. suweonensis decline.

Predation risk is one of the important forces that driving the evolution of prey behavior. Effectively avoiding predators can increase the survival rate and fitness of prey itself, which is also beneficial when an alien species invading into a new environment. In South Korea, bullfrog is an invasive anuran, we conducted experiments on bullfrog tadpoles to evaluate the functions and behavioral adjusting capability of micro-habitat preference. In first experiment, survival rate of tadpoles was highest in submerged vegetation (75.0%, n=20), which was significantly higher than that in the micro-habitat without vegetation (45%, n=20), and the survival rate in emerged vegetation was 50% (n=20), which did not significantly differ from other two treatments. Results shows that submerged vegetation functions as a shelter that reducing predation risks. In second experiment, most of tadpoles preferred staying longer (77.50±29.26% of observation) in submerged vegetation, which was higher than expectation of 50% (t19=4.20,p<0.001). This frequency that tadpole stay in emerged vegetation treatment was 59.17±21.10%, which did not differ from expectation (t19=1.94,p=0.067).The frequency that tadpole staying in submerged vegetation was higher than that in emerged vegetation(t38=-2.27,p=0.029).This results indicated that bullfrog tadpoles tend to stay in vegetation, especially the submerged vegetation. In last experiment, we repeated second experiment by using wounded tadpoles. Tadpoles stay in submerged vegetation increased to 84.58±22.99%, but it did not increase significantly (t38=-0.85,p=0.400) than previous results. The frequency that tadpole stay in emerged vegetation was 77.5±17.54%, which was higher than that in second experiment (t38=-2.99,p=0.005). Results in third experiment indicating that bullfrog tadpoles have the ability to adjust the avoidance behavior according to previous experiences. In summary, bullfrog tadpoles tend to stay in submerged vegetation which functions as a predation-free refuge, and adjust their anti-predation behavior depending on conditions.

Variations in environmental temperature across geographic gradients are expected to produce physiological differentiation and local adaptation of ectotherms depending on their thermal tolerances and physiological sensitivities. Numerous studies focus on the relationship between upper thermal tolerance limits and geographical gradient, important for species response to temperature change. However, current studies are strongly skewed to global-scale projects even though smaller-scale studies convey equally significant findings. Here, we focus on thermal tolerance variations of amphibians along a 500-km latitudinal gradient in Korea. We investigated variations in critical thermal maximum (CTmax) of larvae of Rana uenoi and Bufo gargarizans. We exposed tadpoles under increased temperatures and recorded CTmax as the point when the righting response was lost. We performed regression analyses to explore the relationship between geographical gradient and CTmax using linear mixed-effect models. Latitude was not significant for CTmax in B. gargarizans, whereas CTmax generally increased with latitudes in R. uenoi. Furthermore, average CTmax of B. gargarizans (38.04 ± 0.6 °C) was much higher than that of R .uenoi (35.84 ± 2.27 °C). No relationship between CTmax and geographical gradient and higher values of CTmax might be critical for the larger distribution range of B. gargarizans, because these features of CTmax may enable this species to adapt both dry and moist environments. The positive relationship between CTmax and latitude may suggest a high degree of sensitivity to an environmental gradient in R. uenoi. This pattern is opposite to the general pattern, which is the negative relationship between CTmax and latitude. This opposite pattern of thermal response in R. uenoi may be explained by the counter-gradient variation model, suggesting an evolutionary trade-off acting on thermal physiology. Finally, we suggest the necessity of individual species research for practical and reliable assessments on species response to climate change as they exhibited physiological differentiation.

National Institute of Forest Science in Korea (NIFoS) has been monitored number of individuals for major insect pests, especially Hyphantria cunea (Lepidoptera), and developed the phenological models to predict the effect of climate change. We also investigated fauna of insect pests, damage characteristics, ecological traits, and so on in human-dominated landscapes since 2018. Four tree species, such as cherry tree, zelkova tree, maple tree, and Mugunghwa were chosen for initial stage of the study considered with number of planted trees in Korea and relative preference in societies. Two invasive species belonging to Hemiptera, Metcalfa pruinosa and Ricania shantungensis, were major insect pests on the most tree species in general. Some aphid species, such as Tinocallis zelkowae, Periphyllus californiensis, and Aphis gossypii also damaged to zelkova tree, maple tree, and Mugunghwa, respectively. In cherry trees, damage rates and characteristics of Synanthedon bicingulata (Lepidoptera) and Aromia bungii (Cerambycidae) were investigated. Entrance hole of larvae of S. icingulata was found from the most cherry trees planted along road verges irrespective of tree ages, while damage of A. bungii was generally found from old trees above 30 cm in diameter at breast height, especially planted on dry environments like road verges. To manage the insect pests on urban trees, insecticides are primarily used by spray or tree injection as chemical control methods. However, the use of chemical control methods are faced a lot of challenges due to the change of trend on the attention for human health, and thus, development of environmental friendly methods is becoming more important. For this reason, we have been tried to identify the pheromones and to develop the organic materials.

Disease management of oak wilt, mainly occurred in Quercus mongolicae by Raffaelea quercus-mongolicae in Korea, have been mainly focused on the control of insect vector(Platypus koryoensis) by treatments of insecticide spray, pheromone trap, sticky roll trap, and fumigation of dead or dying trees. For the control the pathogen colonized in trees, culture suspension of antifungal Streptomyces blastmyceticus was injected into trees in the forest by trunk (ChemJet®) or root flare(Macro-infusion) injection methods before or after pathogen inoculation, and the ratios of non-conductive area, discolored area, and re-isolation of the pathogen from the treated trees were calculated for evaluating preventive or curative efficacy. Injection of S. blastmyceticus or the fungicide(Alamo®) showed 41.7% and 45.8% in non-conductive area(%), respectively. In addition, S. blastmyceticus did not show much differences between injection methods and timings in control effect, but fungicide treatment was better in Macro-infusion at root flare or curative treatments. Re-isolation rates of the pathogen in the pathogen only, preventive and curative treatments were 56.9%, 20.6%, and 36.1%, respectively. These results indicate that S. blastmyceticus has better control efficacy than the fungicide commercially available for the control of oak wilt caused by Ceratocystis fagacearum in the United States.

Many forest insect pests and diseases including pine needle gall midge (Thecodiplosis japonensis), black pine bast scale (Matsucoccus thunbergianae), pine wilt disease, and oak wilt disease, have caused serious damage to Korean forest for several decades. For the control of forest insect pests and diseases, synthetic pesticides have been widely used. Although effective, their repeated use for several decades has caused several side effects including environmental and human health concerns, undesirable effects on nontarget organisms, and disruption of biological control by natural enemy. Many Researches have conducted in order to find new and safe type of control agents to reduce environmental and human health concerns. Insect pheromone could be a good candidate for this purpose. Insect pheromone is a chemical that triggers a social response in members of the same species. Until now, thousands of insect pheromone have been identified. These insect pheromone could be classified according to their role. Sex pheromone is usually released by female and attracts male for corpulation. Aggregation pheromone is common in bark and long horn beetles, and used for mass attack on their host plants. In this presentation, we introduce recent research on insect pheromone of tree insect pest in Korea. Field application of insect pheromoen for monitoring and control will be also discussed.

Numerous diseases on trees or forest crops caused by various fungal pathogens have been increasingly reported in many countries. This is due to the fact that the human-mediated movement of the pathogens via wood materials and climate changes affecting worldwide. During a recent survey of tree diseases carried out to identify the fungal pathogens, especially infecting urban trees between 2017 and 2018, numerous fungal pathogens were identified and were confirmed occurring in many parts of the regions in South Korea. This includes Pseudocercospora sp., Desarmillaria sp., Botryosphaeriaceae and the ophiostomatoid fungi. Of those identified, Botryosphaeria spp. were the most commonly isolated from Sorbus alnifolia and Juglans sinensis, and are seriously causing damages on the trees. Although the pathogenicity of the pathogens that belong to Ceratocystidaceae isolated has not been confirmed yet, Ceratocystis species were also commonly collected from Quercus spp. and Prunus sp. in South Korea. Fungal pathogens that belong to Botryosphaeriaceae were commonly associated with branch and twig. These diseases are closely associated with plant stress. In this regard, this raises the importance of the species under a scenario of global change, including climate change and other, especially anthropogenic changes to the environment that place pressure on plant communities. The ophiostomatoid fungi isolated were closely associated with wounds inflicted on the trees and were confirmed occurring. This in turn raises concern to the country, given the fact that this group includes many important and well-known primary pathogens infecting trees and forestry crops. To effectively control the fungi-associated diseases on urban trees, a precise diagnosis of the pathogens is of crucial importance. In this regard, more rigorous identification of the pathogens is needed to better access the relevance of the diseases and decide about the need for control measures.

Brown spots with yellow halos occurred on naturally-infected leaves of Quercus acutissima (sawtooth oak) in Suwon, Korea. Field emission scanning electron microscopy revealed hyphal branching and prevalence of spore chains on the leaf adaxial surface. Non-glandular trichomes were usually colonized by septate hyphae. Hyphae coiled the trichomes and appeared to inhibit the unfolding of trichome rays. Plant cell wall modifications and epidermal shrinkage of trichomes were apparent around the hyphae. Hyphal growth appeared to dissolve the non-glandular trichomes on the abaxial leaf surface. Transmission electron microscopy revealed the presence of fungal hyphae in the naturally-infected trichomes of the oak species. Concentric bodies and intrahyphal hyphae were often found in the hyphal cytoplasm. These results suggest that the foliar trichomes of sawtooth oak could serve as fungal infection sites, as well as protective structures against a variety of external stresses to the woody plant.

The weather factors such as temperature, relative humidity is one of the most important environmental factors in forest ecosystem, and all components in the forest ecosystem are directly or indirectly influenced by climatic conditions. This study was conducted to analyze weather characteristics of three kinds of coniferous forests stands that was PD(Pinus densiflora), PK(Pinus koraiensis) and LK(Larix kaempferi). The HOBO data logger was installed on each of coniferous forests stands for measurement of weather factor from the July 2015 to May 2017. Weather data was collected from a HOBO data logger in the forest stands and weather data of weather stations of from Korea Meteorological Administration was compared for analysis. As a result of comparing the meteorological factors of forest area and non-forest area (weather station), the mean temperature of forest area was relatively low and the relative humidity was relatively high. During the autumn season (September to November), the mean monthly light intensity tends to be lower overall, while the mean monthly light intensity tends to be relatively higher in winter season (November to February). Especially in spring season (March to May), mean monthly light intensity was a clear riser than the other seasons. The differences of weather factor between forest areas and weather stations were reflected the characteristics of forests such as forest type and tree density. In order to analyze more accurately the environmental characteristics for understanding of weather characteristics in each forest stands, it is necessary to study long-term study.

To investigate how biogeochemical processes affect the concentrations and fluxes of dissolved organic matter (DOM) in forested watersheds, the quantity and quality of DOM at the Arbutus Lake Watershed, Adirondack Park (NY, USA) was studied. Spatial and temporal patterns of the quantity (bioavailable/refractory concentrations) and quality (δ13C, aromaticity, and low (LMW; < 1kDa) and high molecular weight (HMW; > 1kDa) of dissolved organic carbon (DOC), nitrogen (DON), and sulfur (DOS) was investigated. DOC and DON constituents passing through a wetland were composed of highly refractory, aromatic HMW components compared to upland streams. DOS was dominated by the refractory, LMW form. A “bioavailability-molecular size model” was developed showing the refractoriness of the LMW DOS compared to the HMW DOC and DON. Also, isotopic signatures of DOS in the inlet catchment of the Watershed revealed that the incorporation of reduced S (e.g., SH-) derived from bacterial dissimilatory sulfate reduction contributed to generating DOS in ground and surface waters. These results provide new information on mechanisms for geochemical DOS formation in forested catchments. Overall, this study highlighted novel approaches comparing sources and transformation of three elemental DOM fractions of DOC, DON, and DOS along various watershed components and a lake nested forested watersheds.

With an increasing demand of timber production, the use of heavy machinery in forest management has significantly increased, causing the changes of soil physical properties and the decline of long-term site productivity. This study was conducted to evaluate the effects of logging slash and machine passes(Harvester 1 pass & Forwarder 10 passes) on physical properties in harvester and forwarder operations. The results indicated that soil bulk density in the non-slash treatment site increased 10%-29%(25~139% in soil penetration resistance) at all soil depths, compared with the slash treatment site. Therefore, the creation of a slash mat could be an effective way to minimize the changes of soil physical properties. In addition, 90% of total soil compaction in slash treatment site was created within harvester 1 pass and forwarder 5 passes. In non-slash treatment site, 84% of total soil compaction was created within first harvester and forwarder passes.

Climate change is likely to be an important determinant to derive change of species distribution along latitudinal gradient. Terrestrial wildlife might shift up toward higher latitude to track their optimal habitats in response to climate change. Thus, understanding whether and how species distribution shifts up along latitudinal gradients will be a predictive tool for assessing how the species will respond to climate change in near future. In this study, we reviewed range shift of various species of wildlife from literature review and predict potential range shift of various animals including invertebrates like ants and spiders in South Korea.

National park sound analysis technology can be used in various fields such as park environment management, climate change monitoring, endangered species monitoring and habitat quality management. The purpose of this study is to propose a national park management plan using sound environmental analysis technology. The study site was Mudeungsan national park. The study period was 2017. The national park sound environment analysis was classified into 1) noise mapping, 2) Trail sound classification, and 3) soundscape analysis. As a result of the noise mapping, the noise region (over 40dB) was 27.6%, the quiet zone (less than 30dB) was 35.3%. The average number of major noise sources per day was 19 automobiles, 10 military loudspeakers, and 17 airplanes. As a result of the trail sound analysis, the very noisy route was 18.4% and the quiet route was 13.8%. As a result of the soundscape analysis, the main types of high noise sound were automobile, machine, loudspeaker, airplane sound. As a result of this study, it was confirmed that Mudeungsan National Park is exposed to intense noise.

Camera traps are mainly used to detect wildlife in protected areas. The captured images are interpreted by the human eye. Such visual interpretation is not only time consuming, but also makes it difficult to maintain data consistency when investigators changed. Recently, deep learning has been detecting object identification, counts, and image description in imagery with high accuracy. In this paper, we introduce the camera trap data processor that can automatically database wildlife species identification by deep learning. The Sobaeksan National Park's Jukryong eco-corridor was selected as a study area. Through the image-tracking algorithm, the minimum bounding rectangle of the wild animal object was detected and each frame was used as a training image. For deep learning, we used a convolutional neural network (CNN) technique, which is preferred in image recognition field. Open source libraries (OpenCV, TensorFlow, and Keras) were used to implement the model, and the software was developed through Python. The study results showed possibilities that it can reduce the survey time and minimize human errors.

This study was conducted to assess ecological network associated with the fragmented wildlife habitats in Taebaeksan National Park. The study areas included Doomundongjae, Hambaesan, Manhangjae and Hwabangjae, which were heavily fragmented due to paved roads in Taebaeksan National Park. The assessment items are based on ecosystem value improvement (species distribution, moving route, functional habitat, topographical features, landscape ecological patch connectivity), nature-human conflict mitigation (wild animal roadkill, size and type of damaged lands, park visitor characteristics), local resident participation (conservation and use resource distribution, environmental preservation activity site), and economic aspects (ecosystem service, landownership). Assessment analysis shows that the fragmented wildlife habitat scores are 5.9000 of Doomundongjae, 6.6209 of Hambaesan, 6.2544 of Manhangjae, and 5.6525 of Hwabangjae, indicating that Hwabangjae is considered to be the most severely fragmented area where connection effort is immediately needed.

With the entry into force of the Convention on Biological Diversity (Nagoya Protocol), the world is increasingly interested in access to biological genetic resources, benefit, sharing, values, and sovereignty. Although there were established various gene banks such as the National Biological Resource Center, Microbial Genome Bank, etc., the system for genetic resources in national parks, the largest habitat for wildlife genetic resources, is weak. The National Park is a core area that includes Baekdudaeganand coastal axis, and also requires national conservation and management as an ecological axis. In this study, we want to secure the data that use designation and management of gene protected areas as well as collecting, searching and sharing of the core gene sources in national parks. Therefore, we have planed the collection and investigating of genetic resources, and research for habitat conservation and management. In addition, we will create a list of genetic resources and systematization, and operate the sharing services of genetic resource to home and abroad in the future. Through these researches, we will conduct a standardization of core genes for national parks and use them for the additional species. It will also stress the necessity and assessment of conservation values for specific species and habitats.

A survey on natural resources in Korea national parks has to be carried out by every 10 years’ period according to the Article 36 stipulated in the Natural Parks Act. Based on this stipulation, natural resources in national parks have been investigated during past 30 years; the results obtained therefrom have been accumulated in the database of the list of wildlife and exploited to identify current state of wild lives. The length of period of the survey on natural resources has reduced from 10 years to 5 years according to the Natural Parks Act amended in 2017 by which the scope of investigation has expanded from that of an investigation of natural resources to that of the investigation of resources in national parks. The resulted investigation on resources in national parks is scheduled to be carried out from 2019. The present study has discussed issues associated with past investigation on natural resources with the specialists of wild lives and managers of national parks to identify and to establish improvement plans thereof from which, the direction of investigation was set to be oriented toward habitats from species of wild lives and be focused on basins from grids. In particular, efforts will be concentrating on an identification and schematization of habitats of wild lives. For such purposes, the present study has distinguished the investigation on natural resources in national parks into investigations on following fields of land, sea, and the humanities; the types of biodiversity, habitats of wild lives, and disturbance factors were also distinguished and the resulted 34 fields of investigation comprised of 13 fields in land, 9 fields in sea, and 12 fields in the humanities were selected. To conduct the project of investigation smoothly, the respective teams of staffs in charge of ecological investigation, in charge of investigation on hydraulics and water gates, in charge of operation of drones, and in charge of analyses of GIS will be constructed. Besides, an evaluation system on states of national parks will be developed through the selection of the fields of investigation that are enabled to provide us with objective assessment on changes therein by every five years.

In recent years, natural populations of indigenous freshwater species have drastically decreased worldwide, predominantly due to anthropogenic pressure, such as habitat destruction, introduction of exotic species, and potentially climate change. Consequently, a number of species are now under threat of extinction. To recover endangered or vulnerable populations, conservation and restoration management efforts through stocking (e.g. assisted migration) or translocation are currently under way in many parts of the world, including Korea. In this study, we evaluated the current population status of three Korean endangered freshwater fish species (the Manchurian trout Brachymystax lenok tsinlingensis and the sculpins Cottus hangiongensis and Cottus koreanus) that play important ecological roles in their respective ecosystems. We found that extents of within-population genetic diversity were generally low in all three species examined, suggesting that their effective population sizes (Ne) have been typically small. South Korean populations of these species were all substantially genetically isolated from one another (except C. hangiongensis with an amphidromous life style), indicating that limited ongoing gene flow has been taking place among populations. We suggest that stocking or translocation for these ecologically important but endangered Korean populations should be undertaken carefully, considering not only genetic diversity of source/recipient populations, but also the ‘natural’ population structure that is possibly related to local adaptation to their particular environments. Further, the genetically unique populations or groups (e.g. National Park populations) of our study species should be managed as distinct conservation or “evolutionarily significant units (ESU)” in the future.

Being repositories of biodiversity, national parks provide more ecosystem services than other areas with different land uses. It is time to establish assessment systems for the core of national ecosystem services - national parks - and implement national plans by expanding the value of national park-oriented ecosystem services and sustainable use to improve ecosystem services. This research was conducted for 13 months from March 2017 to March 2018. To evaluate the value of ecosystem services provided by national parks, a review of preceding studies, a field investigation and expert workshops were conducted, and evaluation criteria and indices were selected. Establishing the standard for this, an evaluation system for national parks’ ecosystem services was developed and tested for Bukhansan National Park. As a result, 14 evaluation criteria and 19 indices were drawn by considering the characteristics of national parks and re-adjusting through colloquiums and expert workshops based on the 21 criteria and 38 indices in the “Evaluation Index for Korean National Ecosystem Services” published by the National Institute of Ecology in 2016. Relevant data to evaluate two criteria for supplying services, seven for adjusting services, and five for cultural services were collected, the characteristics of Bukhansan National Park were reflected, and indices applicable to regional units were finally selected. For a valuation of each function of ecosystem services, market price method, replacement cost method, contingent valuation, averting expenditure methods and hedonic pricing were employed. It is expected that the research results can be useful for establishing management and mid- and long-term plans to secure the sustainability of ecosystem services of national parks and increase their value in the future, improving people’s awareness of the importance of ecosystem preservation, and providing basic materials for education and promotions.

This study was carried out to provide the technology of silvicultural practices and management for regeneration by sprouts in the oak forests distributed on the slope. A total of 1,451 stumps were examined for the following factors relative to the occurrence and growth of the sprouts: stump height & diameter; location & quantity and root collar diameter & height of arisen sprouts. The amount of sprouts deceased or increased as the stump diameter increased. However, it tended to increase with stump height. The difference in the stump height between direction of the upwards (DUS) and downward slopes (DDS) was occurred, because oak trees were felled lower based on direction of the upward for convenience of regeneration works on the slope. The number of sprouts was higher relatively in the stumps of DDS. The rate of arisen side and root sprouts was higher in the stumps of DDS and DUS, respectively. The stump height difference was found to affect the arisen part of sprouts. As a result of comparing the sprouts growth according to the arisen part, there was no difference in the stump of DUS, but the growth of side sprouts in the stump of DDS was higher than that of the root. In order to improve the quality of oak sprouts considering the distribution characteristics of the oak forests in South Korea, it is necessary to apply the silvicultural technique, making the cutting surface parallel with the slope to reduce the stump height difference, to suppress arising side sprouts.

This study is about statistical analysis for growth in species of major trees using in thinning out trees data. Pine forests (Northern Forest Service) used the growth data for three years from 2012 to 2015. And nut pine forests (Eastern Forest Service, Southern Forest Service) used the growth data for three years from 2014 to 2017. And larch forests used the growth data for three years from 2013 to 2016. Lastly, oak tree forests used the growth data for three years from 2014 to 2017. We take growth of the diameter of each species for response variable, and degree of thinning and level of trees, local(cites and counties), age-class(of trees) for the covariates. We focus on comparing the difference of the diameter growth according to each covariates. We use ANOVA for analysis of the difference in the amount of growth in diameter, Tukey's multiple comparisons for post analysis, and regression trees for analysis of a major effect on the growth of diameter. We get some results that the effects of the thinning increase the growth of diameter although there is a degree of difference depending on the region, and there is a difference in the growth of trees according to the level of trees.

This study analyzed site factors affecting the growth of thinned Pinus koraiensis stands in Gangwon-do and Gyeongsangbuk-do, Korea. We investigated 21 site variables, with a focus on soil properties, in 6 regions, where we used 2 types of thinning plots (M;moderate, and H;heavy) and a control. Multiple regression analysis was used to derive tree growth effect factors, specifically mean annual increment (MAI) and periodic annual increment (PAI), based on tree diameter at breast height (DBH) measurements before and three years after thinning. Site factors significantly related to MAI were stand density (-), elevation (-), soil depth in the B horizon (+), and available phosphorus (+). Across regions, thinning intensity had no significant effect on PAI. We found that interactions of the variable thinning intensity with some of the soil physio-chemical variables had an effect on PAI across/within regions. The regression model of PAI against the site variables showed, in descending order, significant results for the elevation, slope, cation-exchange capacity (CEC), effective soil depth, silt, and stand density (R2: 0.924). In conclusion, future studies on the factors affecting tree growth for a species, require first investigation of the optimum environmental conditions for each species, and second application of these results to a soil quality assessment, to ultimately derive the overall characteristics of the site or soil.

This study was carried out to develop individual tree growth model of major coniferous species, Pinus densiflora, Pinus koraiensis, and Larix kaempferi, in Korea. Monitoring data for three year was used in this study and the total number of plots was 48 sites for P. densiflora, 135 sites for P. koraiensis, and 135 sites for L. kaempferi. Individual tree growth of DBH, basal area, and height were analyzed using the correlation coefficients and regressions, and each growth models were developed. The eight kinds of measured tree factors from 1st and 2nd inventory at 3 year intervals were used as independent variables for individual tree growth models: DBH, number of competitors, basal area, site index, stand density index, age, relative height, number of trees per ha. In addition, the competition index calculated through the best method was used as an independent variable. According to the dependent variables, the selected independent variables for the best models were different by species and models. The best models by dependent variables were developed in P. koraiensis. Using the individual tree growth models provided in this study, it is considered to be able to develop the more suitable growth models for P. densiflora, P. koraiensis, and L. kaempferi in Korea.

This study was carried out to compare the growth of diameter at breast height (DBH) between artificial coniferous forest and natural broad-leaved forest. Data was collected from permanent monitoring plots in Research Forest of Kangwon National University, which is located at Chuncheon-si, Gangwon province of Korea. For artificial coniferous forest, 8 plots with 20 m x 20 m size were investigated in 1996, 2001, 2008, and 2014. For natural broad-leaved forest, 8 plots with the same plot size were investigated in 1996, 2001, 2008, 2014, and 2018. Before and after first measurement, silvicultural treatment was operated with various thinning intensity of 40~81% based on the number of trees. After thinning, the density ranged 500 ~ 2,500 trees/ha for natural broad-leaved forest and 800 ~ 3,200 trees/ha for artificial coniferous forest. As a result, periodic annual increment was higher in artificial coniferous forest than in natural broad-leaved forest as compared based on similar stand density. When the upper 10% dominant trees and the lower 10% recessive tree compared, the growth difference was apparently shown between artificial coniferous forest and natural broad-leaved forest. In addition, the periodic annual increment according to stand density was higher in artificial coniferous forest and it decreased as time went by. Overall, when the stand characteristics such as stand density and average DBH was similar, DBH growth was superior in artificial coniferous forest.

Chloroplast genome sequences among wild and cultivated Prunus yedoensis accessions were compared to develop individual specific DNA markers. Prunus yedoensis is one of most popular ornamental tree species planting in roadside and parks in Korea. Also, there are many natural population in Jeju-Island that the wild morphological characteristics are not distinguishable to cultivate. We compared the chloroplast genome sequence and made up consensus cp genome sequence using the 6 individuals, in which two cultivates and 4 wild individuals are collected. The 4 complete cp genome sequence are generated by de novo assembly of the sequencing data generated by Illumina high-throughput sequencing platform and the other two cp genome sequence were obtained from Genebank. The consensus sequence was aligned as 158,149 bp with containing 86,210 bp of LSC, 19,153bp of SSC, and each 26,393 bp of IRA and IRB. A total AT ratio is 63.28% in consensus sequences. Although these are identified same species with the morphological characteristics, we found highly variable sequence in cp genome. A total of 168 SNPs and 531 INDELs were identified and these take 0.106% and 0.336% respectively. One individual was identified highly different cp genome from the others by neighbor-joining tree analysis. This would be good resource to study of genetic diversity in Prunus yedoensis. We identified SSRs from the cp genomes that discriminate the accessions and possibly use for the cultivar specific markers in the further investigation.

The genus Salix (willow) contains 257 species in China, of which two-thirds are shrubs and the rest are trees. Shrub willows have been extensively planted as an excellently sustainable feedstock crop for bioenergy or ideal biomaterial for phytoremediation, and tree willows mainly serve for landscape planting and as an important wood source for such industries as pulp and paper, charcoal, and furniture production in China. As members of the Salicaceae family along with poplars, willows are dioecious catkin-bearing woody plants that propagate easily, grow fast, and have a modest-sized genome. Albeit having the same haploid chromosome number (n = 19) as poplars, willows are more diverse, and their ploidy status can range from diploid to dodecaploid. Furthermore, some shrub willows are able to flower from cuttings in the year immediately after transplantation, suggesting that willows are resilient and could potentially be used as a novel model plant for genetic and genomic research. More recently, the whole genome sequencing of S. suchowensis has been reported and that of S. purpurea released in Phytozome. Despite their comprehensive importance, the genetic and genomic resources available for willow are still insufficient, although some effort has been made. In this presentation, we would like to illustrate the progress of willow research in Jiangsu Academy of Forestry from 1960s, which containing four main parts including collection, conservation, evaluation, and utilization of willow resources.

Intraspecific leaf economic spectrum (LES) traits vary considerably with leaf phenology and plant age, but whether these trait patterns significantly vary between species with different shade tolerances at local scales has rarely been examined. The presence of LES within species at local scales has recently been debated; however, the conclusions are far from universal, and whether the trait-trait relationships are modulated by leaf phenology and plant age needs to be tested. We measured six leaf traits (i.e., specific leaf area, leaf dry matter content, leaf thickness, mass-based leaf nitrogen content, leaf phosphorus content and ratio of nitrogen and phosphorus contents) among different leaf phenological stages (young, mature and old leaves) and plant ages (adult and sapling) for three temperate broadleaf species with different levels of shade tolerance. Intraspecific trait variation (ITV) obviously depended on the species and traits, and interspecies trait variation patterns were inconsistent with the LES prediction. Specific leaf area significantly decreased as the shade tolerance of a species increased, which was in contrast with the global LES prediction. Additionally, 36% and 25% of ITV was explained by leaf phenology and plant age, respectively, for the overall leaf traits of the three species. Generally, global LES holds at the local scale, but trait-trait relationships were strongly modulated by leaf phenology and plant age. The ITV among the leaf phenology and plant age stages was driven by the LES axis and leaf thickness, respectively. We highlight the importance of leaf phenology and plant age on ITV and trait-trait relationships. We provide direct evidence of the LES at a local spatial scale and a seasonally temporal scale, but we argue that variations in LES traits are always reliable for predicting the resource-use strategies of plants at local scales.

Pinus pumila (Pall.) Regel (Pinaceae) (also called Siberian dwarf pine, Japanese stone pine or Haimatsu) is an endemic pine tree distributed in northern Korea, northeastern China, northern Japan, and between the East Siberia and Yenisey River at elevation of ranging from 1000 to 2300 m. Needles, seeds, foliated twigs, roots, oleoresin, and buds of P. pumila are used in northeastern Asian folk medicines to cure favus, dermatoses, neuralgia, rheumatism, tuberculosis and arthritis, as well as in preparation of antihelmintic, diuretic, expectorant, disinfectant, antiscorbutic, and wound-healing remedies. Earlier papers have reported the isolation of diterpenes, monoterpenoids, and triterpenes from the oleoresin of P. pumila. However, the chemical constituents of pine cone of P. pumila have not been studied so far. Our current investigation on P. pumila cones led to the isolation and purification of seven known secondary metabolites, including β-sitosterol (I), daucosterol (II), β-sitosterol palmitate (III), dimethylmatairesinol (IV), stigmast 7-en-3β-ol (V), stigmast 7-en-3-O-β-D-glucoside (6), and stigmasterol (VII). Their structures were characterized by MS and 1D and 2D NMR spectroscopy, as well as comparison with the literature data. It is worth noting that all the seven secondary metabolites (I~VII) were isolated here for the first time from P. pumila, while compounds III~VII have never been reported from the genus Pinus previously.

Genotype Nisqually-1 is the first model woody plant with an available well-annotated genome. Nevertheless, a simple and rapid transformation of Nisqually-1 remains to be established. Here, we developed a novel shoot regeneration method for Nisqually-1 using leaf petiole and stem segment explants. Numerous shoots formed in the incision of explants within two weeks. The optimized shoot regeneration medium (SRM) contained 0.03 mg l-1 6-benzylaminopurine, 0.02 mg l-1 indole-3-butyric acid and 0.0008 mg l-1 thidiazuron. Based on this, Agrobacterium-mediated genetic transformation of stem explants was examined using the vector pBI121 that contains the β-glucuronidase (GUS) as a reporter gene. Consequently, factors affecting transformation frequency of GUS-positive shoots were optimized as follows: Agrobacteria cell suspension with an OD600 of 0.4, 20 min infection time, 2 days of co-cultivation duration and the addition of 80 μM acetosyringone into Agrobacteria infective suspension and co-cultivation SRM. Using this optimized method, transgenic plantlets of Nisqually-1 – with an average transformation frequency of 26.7% – were obtained with 2 months. Southern blot and GUS activity staining confirmed the integration of the foreign GUS gene into Nisqually-1. This novel transformation system for Nisqually-1 was rapid, efficient, and simple to operate and will improve more genetic applications in this model tree.