Cypripedium guttatum (common name: Spotted Lady’s Slipper) grows naturally in one location in Japan. However, the failure of conservation measures to increase the C. guttatum population has created an urgent need to supplement in situ conservation with ex situ conservation. We were contracted by the Ministry of the Environment (MOE) Tohoku Regional Environment Office to develop a method to germinate C. guttatum seeds collected from C guttatum’s natural habitat and stored by the MOE Shinjuku Gyoen National Garden Management Office and to evaluate the efficacy of using preserved seeds, which is essential for promoting ex situ conservation. Prior to attempting to germinate preserved seeds, we conducted a pilot study using 900 seeds collected from C. guttatum maintained in cultivation plots and Oyamada medium developed especially for Cypripedium spp. The 312 seedlings that germinated were subcultured in seedling growth medium; of these, the 99 seedlings that showed growth were removed from their flasks and transplanted to planting trays filled with horticultural soil and grown for 2 years. The 30 surviving seedlings were planted out in experimental plots and the first bloom was observed the following year. Based on these results, we sowed 290 seeds collected in 2014 and stored by the Shinjiku Gyoen National Park Management Office, which resulted in the germination of six seedlings. These seedlings were subcultured in seedling growth medium and ultimately yielded two plants. Based on the results of this pilot study, we conducted a germination experiment using 7,265 preserved seeds collected in 2015. Intermittent germination of 108 seedlings was observed between day 50 and day 800 after sowing. The resulting germination rate (1.5%) was significantly lower than the germination rate of seeds collected from cultivated plants (34.7%) conducted as a control experiment. Of these 108 seedlings, the 101 that exhibited differentiation were subcultured in seedling growth medium; of these, the 57 that showed growth were removed from their flasks and transplanted to planting trays filled with horticultural soil and grown for 2 years. The 22 surviving seedlings were submitted to MOE. This research, conducted as part of MOE’s effort to conserve and increase populations of endangered plants, has yielded the first report both inside and outside Japan of germination of C. guttatum from preserved seeds collected from wild C. guttatum and demonstrates the efficacy of using preserved seeds for ex situ conservation.

We examined improvements of water quality and residence time after a river rehabilitation project in the “Hira-ko” and “Yanagihira-ko” lagoons, and the effective conservation of water quality in the semi-enclosed lagoons around the coastal area of the Lake Biwa. When we started the research, the residents had been unable to feel the improvement of the water quality even after countermeasures by the project. According to the project report data, the lagoon dredging could reduce phosphorus efflux rate from sediments, and then such as phosphorus, total (TP) and soluble reactive phosphorus (SRP) from August to November, and cell densities of phytoplankton species occurring from August to September, have decreased after 2010, when an intake from “Ohta-gawa” river was installed. Further analyses revealed that several species, such as Anabaena (Dolichospermum) macrospora, which is one of typical blooming and musty odor producing cyanobacteria, decreased until 2015. The dominant blooming cyanobacteria shifted to several other species, such as Anabaena (Dolichospermum) affinis, and relative abundance of diatoms increased after 2016. We estimated the overall inflow rate to discuss the appropriate residence time of the “Naiko” lagoons. The estimation of inflow by the river rehabilitation project was significantly underestimate the inflow rate in irrigation period (May to August) because the most of inflow measurements undertook in non-irrigation period (September to April), so the residence time in irrigation period, which was 15-17 days, was overestimated in the report, although inflow rate from “Ohta-gawa” river was around one-half of the initial project plan. The introduction of the additional inflow, which has been conducted by the residents' organizations of Shina-cho for rural community in order to compensate the shortage in the intake from “Ohta-gawa” river, could decrease residence time as much as 7 days in monthly average during operation months, and even 26 days in October 2018 when the evaporation exceeded precipitation and inflow rate was minimum.

The water quality has been improved around the coastal area of the Lake Biwa after decrease in pollution load of lake sediments due to a river rehabilitation project, aiming restoration of lacustrine wetlands around the Lake Biwa. The local residents were considering how they can take over the conservation activities at “Hira-ko” and “Yanagihira-ko” lagoons for their community. We have examined the potential role of biodiversity on the watershed ecosystem and the conservation activities by local residents and discussed with them about issues to their conservation activities on “naiko” lagoons and adaptive management of seasonal regulation of residence time of the lagoons for water quality. We have made hearing investigation and conversation with them, and it was found that that the regulation of inflow should be an essential task to for the water exchange of the lagoons. Based on the seasonal variations in the possible inflow rate and TP of the stream water and additional inflow from a fish breeding facility, shortening the additional inflow period from September to October should not only be desirable for effective reduction of residence time, but also practical for lagoon conservation activities by local residents who desire to enjoy the native fish species, because the operation can result in interception of the seasonal spawning migration of native fish species from March to August. The local residents could organize the activities within their residents' organizations to engage the maintenance of their farmland and residential area as well as conservation of the lagoons. Shared sense to respect the historical value of the place among the residents who remember experiences to enjoy living organisms can promote their conservation activities.

Epipogium roseum (D.Don) Lindl.(Orchidaceae), is a mycoheterotrophic plant that relies on symbiotic fungi to obtain resources necessary for growth. The species is designated as near threatened (NT) in the 2020 Red List of the Ministry of the Environment of Japan. Many aspects regarding its distribution and ecology are unknown, as it emerges above ground only during the flowering period and relies on symbiotic fungi as well as on leaves of evergreen broadleaf trees decomposed by them. A mature evergreen broadleaf forest, which is rare in urban areas, remains in Yokohama National University, where an E. roseum plant community with more than 300 individuals was discovered in 2019. However, multiple environmental modifications have been made, including the reclamation of its natural habitats. Therefore, following environmental restoration in March 2021, we studied the recovery status of the E. roseum population, with the aim of restoring the environment of its natural habitats to recover the population as well as gaining knowledge regarding its conservation. We examined the changes in inflorescence morphology during the flowering period and the number of emerging individuals before and after the environmental restoration. The results indicated that individuals that flowered in the year studied had shorter inflorescence lengths and fewer florets than those that had flowered before the environmental modification. The individual size showed a tendency to recover over time. We also found that the distributional area of E. roseum changed due to environmental alterations. These findings will be useful for the maintenance and management of mature evergreen broadleaf forests remaining in urban areas from the perspective of biodiversity.

Questionnaire surveys and analyses were conducted in Japan and Taiwan on people's images of "symbiosis" and "relationship between mankind and nature". For the relationship between two elements (A and B), three types, namely, "separate type", "attachment type" and "inclusive type" were set as the diagrams. Among the three types, each of term "symbiosis" and "relationship between mankind and nature" was asked about the closest image, and received an answer. The respondents to this questionnaire were conducted in Japan and Taiwan for people who had a lot of interest in and relationship with nature, and 141 people in Japan and 223 people in Taiwan responded. The most common image of "symbiosis" was the " attachment type," with about 57% in both countries. The next most common image was "separate type", with about 29% of Japan and about 24% of Taiwan, and "inclusive type" being in the low 10% range in both countries. On the other hand, in terms of the image of "relationship between mankind and nature," the "inclusive type" was the most common, with Japan at about 74% and Taiwan at more than 77%. The next most common was " attachment type" in both countries, and the "separate type" was the lowest in both countries. In this way, many people had different images between the term “symbiosis” and the “relationship between mankind and nature”, with the percentage being about 76% in Japan and 74% in Taiwan.