In the pursuit of sustainable national park management, park managers need to understand the interests and activities of their diverse visitors in order to conserve the natural environment and offer a better visitor experience. This study aimed to examine the effectiveness of using non-geotagged social media data from posts by park visitors for park management in comparison with geotagged data, which has been studied more extensively. We compared (1) visitors’ sociodemographic characteristics between geotagged and non-geotagged social media users through an onsite survey in Nikko National Park, Japan, and (2) the content of geotagged and non-geotagged photos shared within the study area on X (formerly Twitter). Our results showed that visitors in their 30s and 40s and foreign visitors had a greater tendency to use geotags. Non-geotagged photos more frequently and deeply capture nature-based activities and interests, including activities on trails, such as mountain climbing and hiking, and an interest in diverse animals and plants and landscapes that are less accessible. These findings indicate that non-geotagged social media data may have less age and nationality bias and advantages over the more widely-used geotagged data in capturing various nature-based experiences offered by national parks. Leveraging both geotagged and non-geotagged data can enable park managers to implement sustainable practices catering to a broader range of visitor interests and activities, contributing to the overarching goal of sustaining the natural environment while also enriching the visitor experience within national parks.

The relative diffusion coefficient (D_r) of solutes in soils is directly proportional to the “nth” power of the volumetric soil water content (θ), where n is an empirical parameter, which normally ranges between 1 and 2. The existence of a breakpoint (θ_br) in the relationship between θ and D_r has been demonstrated at low-θ, in which the value of n becomes approximately 4 when θ < θ_br. The change in n can be attributed to various mechanisms, including drastic changes in the geometrical distribution of pore liquid water caused by dehydration. However, as direct D_r measurements require considerable time to render sufficient data at low-θ, few studies have measured D_r at θ < θ_br, and the relationship between D_r and θ at θ < θ_br remains unclear. In this study, we investigated if the indirect D_r measurement method can be applied in the low-θ region of θ < θ_br. An indirect method for measuring D_r was employed to determine the soil electrical conductivity (EC_s). Using dune sands in which the presence of θ_br was confirmed, D_r from high- to low-θ was calculated based on EC_s measurements and compared with directly measured D_r. The relationships between θ and D_r calculated based on EC_s and using the transient state method were almost the same. D_r could be calculated from EC_s even at θ < θ_br. The results confirmed that the indirect Dr measurement method can be applied for the low-θ region of θ < θ_br.

Geotagged social media data have been used widely for visitor monitoring in protected areas. The data might, however, over or underestimate visitors from specific countries due to nationality bias, i.e., differences between nationality of actual visitors versus those visitors who post on social media. This study aimed to quantify nationality bias in social media data for visitor monitoring. We conducted a questionnaire survey in Nikko National Park, Japan. Questions covered the nationality of visitors and their usage of social media, and other visitor attributes and behavior. Foreign visitors had significantly different attributes and behaviors compared to Japanese. Non-Japanese Asian visitors were overrepresented in Instagram and Facebook data. In comparison, the X platform was more representative of all visitors. Nationality bias in different platforms needs more attention and further study in different areas.

In recent years, Mongolia has witnessed an increase in not only wheat fields, which have been present for a long time, but also rapeseed fields. This has led to increasing concerns about soil degradation due to inappropriate cultivation. This study aims to determine the impacts of rapeseed production on soil water storage in Mongolia. The soil water content and matric potential were measured in wheat and rapeseed fields and adjacent steppe rangeland for five years, including crop production and fallow years, and the soil water storages in the fields were compared. The results demonstrated that the matric potential below the root zone in the rapeseed field and both rangelands was drier than the wilting point, whereas the potential in the wheat field was usually almost the same or wetter than this point. The comparison of the amount of soil water storage during the fallow year with that of the adjacent rangeland showed it to be 5–10% higher for the wheat field and almost equal for the rapeseed field. Field management must consider the fact that rapeseed fields use more water than is required by wheat fields and that less water is stored during fallow periods.