Taiwan has a long history of reforestation due to land degradation. However, there is a lack of understanding of how tree species grow on reclaimed lands. This study looked at tree sizes, vulnerability, and health of economically important Zelkova serrata and Quercus glauca trees planted on reclaimed agricultural lands. Thirteen former agricultural sites with trees of six to seven years old were sampled along the elevation from 107 to 2514 m above sea level. Results showed that increasing inter-tree competition reduced tree sizes and health and increased vulnerability to damage, primarily wind, for both tree species. For example, a 1 m² ha⁻¹ increase in inter-tree competition was associated with a 5.68 cm decrease in tree diameter, a 3.21 m decrease in tree height, a 59.31% decrease in tree health for Z. serrata. Responses of Z. serrata to inter-tree competition were generally stronger than those of Q. glauca. Elevation generally reduced tree sizes of both species and reduced health of only Z. serrata trees. Stand density has minimal effects on the tree attributes of both species. Our study suggests that Z. serrata responds strongly to inter-tree competition leading to stratification of stand structures, which agrees with past studies showing Z. serrata developing different growth strategies. Q. glauca could resist inter-tree competition so that suppressed trees could compete with its neighbors. This supports past observations that Q. glauca could persist under suppression. Our findings of the elevation caution planting both tree species outside their native habitat ranges, which was not shown before.

In the present study, we aimed to develop an efficient prediction model for the site index of hinoki (Chamaecyparis obtusa) plantations in Higashi Yoshino Village, Nara Prefecture, Japan. For this purpose, we trained a convolutional neural network (CNN) model, then investigated the accuracy of site index prediction and the reproducibility of topographic factors from digital elevation model (DEM) image data acquired using an aerial laser scanner. We also examined terrain red–green–blue (RGB) images, derived from the DEM, as an alternative form of input data. The terrain RGB images outperformed DEM images in terms of prediction accuracy and reproducibility for all evaluation indicators. Reproducibility analysis of elevation, slope, and orientation revealed particularly high accuracy (coefficient of determination > 0.95). Although further improvements to the model are needed, our results emphasize the practicality of using a CNN model combined with terrain RGB images for site index predictions. This approach has the potential to achieve prediction accuracy close to or even surpassing those of existing methods, while requiring fewer types of input data.

The Chinese government has set ambitious climate reduction targets: the country has pledged to reach their carbon dioxide (CO2) emission target before 2030 and achieve climate neutrality before 2060. To achieve this ambition, harvested wood products (HWP) play an essential role in offsetting the residual emission. However, knowledge gap exists in terms of the role of HWP in achieving pledged ambitions expressed in Nationally Determined contributions (NDCs) and long-term low-emission development strategies (LT-LEDS). This study projects the size of the Chinese HWP carbon pool until 2060 based on the 2019 Refinement of Intergovernmental Panel on Climate Change (IPCC) Guidelines for National Greenhouse Gas (GHG) Inventories (PA2019) and the GLOBIOM-China land use model. While the net carbon sequestration of the HWP carbon pool has increased in China over the last two decades, our assessment shows that there is a risk that the net sink of HWP carbon may have peaked as of 2020 and will saturate and decrease with time. As of 2020, the annual net GHG sink for the HWP carbon pool was estimated at -173.45 MtCO₂, and under a business-as-usual (BAU) scenario, this rate would be reduced to -131.10 MtCO₂ by 2060. A high bio-energy demand scenario, consistent with limiting global warming to 1.5◦C, leads to a greater reduction in the HWP sink, which by 2060 will amount to only -33.33 MtCO₂. However, the net carbon sequestration rate of HWP could be enhanced to -136.54 MtCO₂ if efforts are made to enhance the domestic consumption of semi-finished wood products. As a result, although the HWP is currently providing China with significant reductions in its economic emissions on a national level, its development over time should be fully integrated into national strategies directed at mitigating climate change and meeting international obligations.

Collisions between wildlife and vehicles are a growing conservation issue in Nepal. We examined spatial and temporal patterns of wildlife roadkill in Banke National Park and Bardia National Park. During six surveys conducted between April and June 2022, 101 animal carcasses were recorded along a 126-km stretch of the east-west national highway that runs through the two national parks. The opportunistic secondary data from national park records showed that there were 375 roadkill incidents between July 2017 and May 2022. Based on primary and secondary data (476 road fatalities from 35 different species), mammals were the most affected group (77.31%), followed by reptiles (12.61%), birds (6.93%), and amphibians (3.15%). The number of road fatalities per km was higher in Banke (0.77) than in Bardia (0.49). Poisson regression models show that road sections with high visibility (β = −0.41) and road sections passing through human settlements (β = −0.72) have fewer road fatalities. In contrast, mortality rates were higher on road sections that crossed water bodies (β = 0.54), passed through the core of the national park (β = 0.82), and near park checkpoints (β = 1.03). Seasonal variations in traffic accidents show a higher number of fatalities in winter (χ² = 17.54). Overall, our results identify landscape features that may make roads more susceptible to traffic accidents, highlighting the need to consider their spatial distribution when prioritizing roadside mitigation measures. We recommend regulating vehicle speeds along wildlife concentration areas and clearing roadside vegetation to improve visibility, especially in winter, should help reduce the number of wildlife roadkill.

Tokashiki Island with convenient access from urban areas and blessed with rich marine resources, attracts numerous tourists seeking recreational activities such as diving and snorkeling. The island heavily relies on a tourism industry centered on marine resources. However, with the escape and rapid increase in the population of Japanese boars, which were initially introduced as livestock, various damages have become evident. Particularly in recent years, a major concern for local tourism industry stakeholders has been the predation of sea turtle eggs by boars because sea turtles are highly popular marine creatures among snorkelers and divers. Identifying the locations of sea turtle egg predation by wild boars and examining the conditions and situations that increase the likelihood of damage are crucial tasks in considering measures to mitigate the impact. Therefore, in this study, we analyze the factors influencing egg predation using a two-variable logistic regression model. The damage site data from on-site surveys conducted during the 2023 nesting season were utilized along with topographical, land-use, and vegetation data. Explanatory variables included in the regression analysis are average slope angle around the damage sites, predominant vegetation around the damage sites, distance to buildings, distance to roads, distance to rivers, and width of the sandy beach. Results from the regression analysis revealed that the predominant vegetation surrounding the damage sites and the width of the sandy beach significantly influence the risk of damage. Despite encountering challenges during the regression analysis, such as utilizing data from a single year’s nesting season, relatively coarse geographical information, and limited explanatory variables, future endeavors should focus on collecting and accumulating more data for a more comprehensive analysis. Nevertheless, this analysis underscores the value of information provided by such studies in establishing spatial priorities for implementing measures to capture wild boars and protect sea turtle eggs in the future.