Forest practices for mountainous areas can enhance the scenery value and function of forests. However, forest scenery management is rarely implemented except for conservation areas and public forests. In this study, we first used the viewshed analysis to extract visible and invisible zones from the surface areas of ordinary mountains in Korea, and then we used spatial aesthetic analysis to interpret the human-recognized characteristics on the visible zones of mountain scenery. Finally, based on the results of both analyses, reasonable guidelines for forest practice planning were proposed to improve the scenery of ordinary mountains. The result shows that the viewshed analysis made it possible to extract visible and invisible areas from the surface areas of ordinary mountains, and to determine the scale of zoning for forest practices to improve mountain scenery. In addition, using spatial aesthetic analysis, it was possible to explain the characteristics of mountain scenery according to distance and elevational differences between viewpoint and target, and to suggest a treatment target and direction for forest practices to improve the mountain scenery. This study is meaningful in that the viewshed and spatial aesthetic analyses were applied to evaluate the current scenery of ordinary mountains and to present guidelines for forest practice planning to promote their own scenery values.

Drought damage and waterlogging damage are the most frequent abiotic injuries throughout the lifespan of trees. Nonetheless, because the signs of visible damage are similar between these types of injury, physiological indicators must be analyzed to make a scientific differential diagnosis. This study was aimed at investigating growth and physiological indicators of drought (DS) and waterlogging stress (WL) in Prunus yedoensis. Overall growth indices such as tree height, diameter at root collar (DRC), and total dry weight could be ranked in the decreasing order “control > DS > WL.” In particular, there was a prominent decrease in root growth in WL, and DRC in DS was lower by 9.2% than DRC before the experiment. As for water saturation deficit (WSD) increased to 37.4% by 28 days after treatment initiation (DAT) in DS. WL showed a sharp decline of photosynthetic indicators such as the net photosynthesis rate (A), stomatal conductance (g_s), and maximum carboxylation rate (V_cmax) starting from 7 DAT. By contrast, DS manifested a significant decrease starting from 14 DAT. The DS had higher levels of leaf and root inorganic components than WL did, suggesting an improvement in the osmoregulatory ability. The overall nutritional status of WL was low due to deterioration of the absorption function of the roots. In both DS and WL, energy transfer rates of photochemical reactions, e.g. absorbed photon leads to reduction further than Q_A^- (Φ_PO), absorbed photon leads to electron transport further than Q_A^- (Φ_EO), and absorbed photon leads to reduction of Q_A^- (Ψ_O), decreased, as did vitality indices, e.g. the performance index on absorption basis (PI_abs), driving force on absorption basis (DF_abs), and the structure function index on absorption basis (SFI_abs). However, WL featured a decrease in Electron transport flux from Q_A to Q_B (ETo/RC) and Electron transport flux until PSI acceptors (REo/RC), whereas DS experienced a slight increase or almost no change. Consequently, PI_abs, DF_abs, SFI_abs, and the drought factor index are highly sensitive environmental-stress indicators, whereas WSD, DRC growth, chlorophyll a content, ETo/RC, and REo/RC appear to have high potential as diagnostic indicators of drought or waterlogging damage.

Distance is one of the important factors in determining transportation cost and travel time, and it can be easily estimated by measuring the circuity of road networks. This study calculated the circuity factors to estimate the network distance for 27 forest roads (about 105 km) in South Korea. For this purpose, ridge, mid-slope, and valley roads were classified according to the construction location of the mountain slope, and the weighted and unweighted circuity factor (each 500-m section) were calculated. The average value of weighted circuity was 1.55: mid-slope roads (2.09), ridge roads (1.36), and valley roads (1.09). The average unweighted circuity factors were 1.61 for mid-slope roads, 1.21 for ridge roads, and 1.07 for valley roads. This study found that the circuity of the forest road network was most affected by the mountain terrain. In addition, the circuity factor increased with increasing network distance in the mid-slope roads but was not affected by the network distance in ridges and valleys. To improve the efficiency of transportation in the forest road network, it is important to locate the ladings and properly connect with the public road network.

Forest roads are an essential facility for sustainable forest management and protection. With advances in survey technology, such as Light Detection and Ranging, forest road maps with greater accuracy and resolution can be produced. This study produced a 3D map for establishment of a forest road inventory using a Mobile Laser Scanning (MLS) device mounted on a vehicle in four study forest roads in Korea, in order to review its precision, accuracy and efficiency based on comparisons with mapping using Total Station (TS) and Global Navigation Satellite System (GNSS). We counted the points that consist of the cloud data of the maps to determine the degree of precision density, and then compared this with 50 points at 20-m intervals on the centerlines bisecting the widths of the study forest roads. Then, we evaluated the relative positional accuracy of the MLS data based on three criteria: the total length of each forest road; the Root Mean Square Error (RMSE) obtained from coordinate values of the MLS and TS surveys compared to the GNSS survey; and the ratios of the centerlines extracted by the MLS and TS surveys overlaid to the buffer zone by the GNSS survey. Finally, we estimated the time and cost per unit length for producing the map to examine the efficiency of MLS mapping compared to the other two surveys. The results showed that the point cloud data acquired by the MLS survey on the study forest roads had very high precision and so is sufficient to produce a 3D forest road map with high-precision density and a low RMSE value. Although the equipment rental cost is somewhat high, the fact that information targeting on all spatial elements of forest roads can be obtained with a low cost of labor is a benefit when evaluating the efficiency of MLS survey and mapping. Our findings are expected to provide a quantitative assessment of both maintaining sustainable effectiveness and preventing potential environmental damage of forest roads.

Climate change affects the frequency and intensity of extreme weather, such as drought and floods. This study aimed to investigate the effects of drought stress on the growth and physiological characteristics of Z. jujuba var. inermis based on the RCP 6.0 scenario. The experiment was performed in a soil-plant daylight system (SPDS) chamber under four conditions: Control-WW, Control-DS (Drought), RCP 6.0-WW (CO 2 650 ppm, control + 3°C), and RCP 6.0-DS. Although the net photosynthetic rate (A) was higher under RCP 6.0 than the control condition, V cmax and J max , which indicate the photosynthetic capacity, were lower by 19.6% and 27.8%, respectively. Furthermore, in the RCP 6.0 group, the carbon fertilization effect tended to stimulate growth; thus, the total dry weight in RCP 6.0-WW was approximately 35% higher than that in Control-WW. When the drought treatment was included, A decreased by 57% in Control-DS compared to Control-WW, and in RCP 6.0-DS, A decreased by 73% compared to RCP 6.0-WW. Moreover, RCP-DS showed the lowest values of V cmax , J max , PI abs , DF abs , and SFI abs , meaning that the photosynthetic capacity and vitality of the photosynthetic apparatus were diminished under combined climate change and drought stress. Furthermore, stomatal limitations (Ls) regulated photosynthesis in Control-DS, whereas in RCP 6.0-DS, non-stomatal limitations, in this case V cmax , J max , PI abs , DF abs , and SFI abs , were observed. Despite a decrease in mesophyll conductance (g m), g m /g s remained relatively high. Furthermore, even with stomatal closure, g m was maintained at a relatively high level by utilizing the intercellular CO 2 concentration (C i), demonstrating the plant's response to drought stress. Although there was an increase in the overall biomass, it was noted that water consumption increased under additional drought stress, showing that growth and physiological damage were aggravated. Therefore, it is essential to conduct experiments related to the growth and physiological characteristics of commercially valuable seedlings such as Jujube to identify the adverse effects of climate change alongside extreme weather. Further, active efforts with regard to plant management should be undertaken in addition to the implemented measures to reduce greenhouse gas emissions. 12

Accurate spatial information on forest roads is important for forest management and harvest operations. This study evaluated the positional accuracy, shape similarity, and cost of three mapping techniques: GNSS (Global Navigation Satellite System) mapping, CAD file conversion (as-built drawing), and image warping. We chose five road routes within the national forest road system in the Republic of Korea and made digital road maps using each technique. We then compared map accuracy to reference maps made from field surveys. The mapping and field-survey results were compared using point-correspondence, buffering analysis, shape index, and turning function methods. The comparisons indicate that GNSS mapping is the best technique because it generated the highest accuracy (Root Mean Square Error: GNSS mapping 1.28, image warping 7.13, CAD file conversion 13.35), the narrowest buffering width for 95% of the routes overlapped (buffering width: GNSS mapping 1.5 m, image warping 18 m, CAD file conversion 24 m), highest shape similarity (shape index: GNSS mapping 19.6–28.9, image warping 7.2–10.8, CAD file conversion 6.5–7.4), and smallest area size difference in turning function analysis (GNSS mapping 2814–4949, image warping 7972–26,256, CAD file conversion 8661–27,845). However, GNSS requires more time (236 min/km) and costs more ($139.64/km) to produce a digital road map as compared to CAD file conversion (99 min/km and $40.90/km) and image warping (180 min/km and $81.84/km). Managers must decide on the trade-off between accuracy and cost while considering the demand and purpose of maps. GNSS mapping can be used for small-scale mapping or short-haul routes that require a small error range. Image warping was the lowest cost and produced low-accuracy maps, but may be suitable for large-scale mapping at the regional or national level. CAD file conversion was expected to be the most accurate method, because it converted as-built drawings to a map. However, we found that it was the least accurate method, indicating low accuracy of the as-built drawings. Efforts should be made to improve the accuracy of the as-built drawings in Korea.