This study aims to reference United States academic library databases to elucidate the characteristics of wetlands education research. It focuses on the evaluation trends pertaining to research related to wetlands education, both quantitatively and in terms of factors that have attracted the most attention. Bibliographic databases were utilized to scrutinize research trends and to conduct bibliometric analyses that emphasized the understanding of secular changes in research related to wetlands education. The literature was widely reviewed without being limited to speciﬁc academic journals. Speciﬁcally, the investigation was oriented toward (1) comprehending the secular changes in research on wetlands education, (2) organizing research topics by title, abstract, keywords, and publication type, and (3) identifying trends in the themes encompassing wetlands education research. The results of the survey indicate that wetlands education is an important aspect of environmental education in the sustainable development goals era at this critical juncture when human civilization is vulnerable to climate change. Thus, rather than being limited to the natural sciences, wetlands education must be highlighted and integrated into interdisciplinary curricula that include the social sciences. This emphasis should be achieved through the amelioration of knowledge, understanding, and communication related to wetland conservation. It is critical for researchers to clearly distinguish between the development of educational curricula and activities and to accumulate research regarding their applications. The present review found that the type of papers shifted, and the overall number of papers increased greatly between 1993 and 2002. The marked increase in the number of articles indicates that the domain of wetlands education research is still developing. As the ﬁeld of wetlands research continues to grow, researchers must cross disciplinary boundaries to resolve problems such as climate change and water crises because such issues cannot be handled by any single domain of study.
Whether wetland plants retain their seed bank in the soil even after the disappearance of the seepage marsh was examined using the seedling emergence method. Soil samples were collected from three locations where seepage marsh with wet grassland existed approximately 30 to 10 years ago and from one seepage marsh where wet grassland currently exists. The soil samples were cultured in a suitable environment, and wetland plants germinated in soils from all study sites. The seedlings of Drosera tokaiensis, Rhynchospora spp., Utricularia spp., and Haloragis micrantha occurred commonly in the soil samples from the areas where the seepage marsh existed in the past. In contrast, seedlings of many recoded species including Eriocaulon nudicuspe and Moliniopsis japonica did not occur. Similarly, from the existing seepage marsh samples, germinated species comprised only a few of the species growing there. Although more detailed investigation is needed, our ﬁndings suggest that certain species of wet grassland on seepage marshes form a soil seed bank for a long time even after the disappearance of the vegetation; however, this is not the case for all species.
In the southern part of the Owari Hills, we investigated the seasonal changes in the discharge, temperature and
water chemistry of two springs: one from metamorphic rock (hornfels) and the other from gravel layers. Compared to the water from a nearby stream, the water from the two springs had smaller seasonal changes in temperature, was clearer with less turbidity and colour and had a lower concentration of dissolved oxygen (2.6 mgO2 L-１). Between the two springs, there was a clear difference in pH and dissolved inorganic substances. The spring water from the metamorphic rock body was weakly acidic (pH 6.0) with a high concentration of dissolved inorganic substances (electric conductivity 16 mS m-１); the spring water from the sand and gravel layer was acidic (pH 4.7) and had a low concentration (electric conductivity 5 mS m-１). These differences were attributed to the groundwater inﬁltration process and acid buffering of the soil. The SiO2 concentration reﬂects the residence time of groundwater; it was 26 mg SiO2 L-１in the spring water from the metamorphic rock and 10 mg SiO2 L-１ in the spring water from the sand and gravel layer. Therefore, the groundwater inﬁltration rate seems to be slower in the metamorphic rock than that in the sand and gravel layer. On the soil surface, H+ is supplied from the nitriﬁcation of NH4+-N produced by the decomposition of organic matter and CO2 produced by respiration. H+ in acidified groundwater is consumed during the weathering of the bedrock because of acid buffering. Because the metamorphic rock is hard and it has more places inside to be weathered than the sand and gravel layer, the metamorphic rock appear to supply more dissolved inorganic substances than the sand and gravel layer. However, the dissolved inorganic nitrogen in the spring water from the sand and gravel layer was mostly NO3--N and approximately 50% of that in the spring water from the metamorphic rock. This may be due to nitrate reduction by iron bacteria that prefer the circumneutral and low oxygen conditions of the spring water from the metamorphic rock.
In SATOYAMA environments that have been varied due to changes in the lifestyle of local people, the habitat of some species has also been altered. Therefore, to conserve the biodiversity of such environments, including Katano-kamoike pond where is managed as reservoir for rice cultivation and traditional hunting area, management plans that consider the ecology of target species are required. In the present study, I investigated the effect of water level on the foraging behavior of Bean geese Anser fabalis middendorffii at Katano-kamoike pond in Kaga City, central Japan; based on the results, I propose a water-level management plan. During the study periods, the water level at the site, which was measured with a standard water-level gauge, ﬂuctuated between 20 and 65 cm. In general, the proportion of foraging Bean geese ranged from 0 and 1 when water depth was lower than 80 cm and those were low at higher water depth. In addition, the proportion of Bean geese foraging for the fruits of Water chestnuts Trapa natans decreased as the water level rose, while that of geese foraging for the rhizomes of emerging plants increased. These results were conﬁrmed statistically using a generalized linear mixed model. Because the foraging behavior of Bean geese was affected by the water level at the study site, I suggest that it would be advisable to maintain a low water level in order to conserve the foraging grounds and the ﬂexibility in the food selection of Bean geese.