We analyzed vegetation cover and the diversity of native and alien aquatic plants in the Lake Teganuma watershed (northeastern Chiba Prefecture). Using digital elevation model data, we established six third-order sub-watersheds, which were further divided into second- and first-order sub-watersheds. The easternmost third-order sub-watershed (Kamenari) contained large tracts of agricultural landscape. Land cover on the western sub-watersheds was more densely developed through human activity. Vegetation cover was derived from the normalized difference vegetation index (ASTER data), and extant data on distributions of aquatic species were digitized. Aquatic plant diversity and vegetation cover were substantially higher in Kamenari than in the five western sub-watersheds. Several submerged species in Kamenari are currently listed in the prefectural red data book. Only common emergent species occurred in the western areas. There was a strong correlation between vegetation cover and native species diversity in Kamenari, but not for alien species. Thus, the eastern Kamenari sub-watershed is a hot spot for aquatic plant diversity (especially native species) in the Lake Teganuma watershed.
The traditional Japanese rural landscape (satoyama) is composed of grasslands, paddy wetlands, and coppice woodlands. This landscape, which is rich in biodiversity and traditional regional culture, is considered a potential source of biomass production for renewable energy. Coppice woodlands have limited tree species diversity due to frequent felling, and grassland species dominate on the forest floor. Outstanding biodiversity in grassland species and wetland species is the typical property of the satoyama-landscape. Because the large-scale (>100 km) distribution of biodiversity in this landscape is not known, we developed a method to evaluate measure it directly that involvedby a ground survey along a very long line-transect. and We mapping mapped of indicator plant species of grassland and paddy wetland along the survey lines, and counted the number of grassland species and paddy wetland species. We identified rich satoyama-landscape biodiversity in both grassland and paddy wetland herbs in the northeastern Kanto region. (northern Ibaraki Prefecture and eastern Tochigi Prefecture), bBut centers of richness differed between the systems, and Ggrassland species were plentiful in cool areas and paddy wetland species were plentiful in warm lowland areas. We need to conserve both typical traditional ruralsatotoyama -landscapes, with their rich biological diversity (northeastern Kanto region), and centers of richness of grassland and paddy-wetland species.
To clarify the factors affecting damselfly assemblages in reservoir ponds, we surveyed the density of adults in 56 study ponds in rural areas of Iwate Prefecture, Japan, during 2008 to 2010. To compare the impact of indirect effects of common carp (Cyprinus carpio) with direct effects from environmental factors, we quantified indirect effects of common carp that were mediated by aquatic plants. For environmental factors, we examined the coverage of aquatic plants, the presence of marginal forests, the presence/absence of bullfrogs (Rana catesbeiana), forest dimensions, and pond density around each pond. Our results revealed that the presence of common carp had significant negative effects on the coverages of floating-leaved plants and submerged plants. In addition, the coverage of aquatic plants, which was defined as a function of carp occurrence, had significant positive effects on damselfly densities. This indicates that the introduction of common carp is the strongest operator in this region, modifying damselfly assemblages by reducing the local availability of aquatic plants.
The Basic Act on Biodiversity (June 2008) provided that prefectures and municipalities shall endeavor to set a basic plan on conservation and sustainable use of biodiversity within their areas. This Local Biodiversity Strategy is expected to ensure local biodiversity conservation, reflecting the inherent ecosystems and society. Nevertheless, there are few municipalities or local governments which have already implemented the strategy. In this article the attitude of governmental officials toward the implementation of this strategy was elucidated through a questionnaire survey in order to determine what prevents its implementation. The outcome of this study indicates that small municipalities especially haven't been informed about the provisions of the strategy and haven't started its formulation. The lack of inherent ecosystem data, the difficulties of consensus building, and the ambiguous necessity of the strategy seem to be barriers to its formulation. In order to promote the formulation and implementation of the strategy, the provisions of the strategy should be made known especially to small municipalities. To show the necessity and merits of the strategy clearly may be also important. In addition to this, collaboration and coordination with research institutions and citizen groups might be effective.
Global warming will strongly modify the phenology of alpine plant communities. Long-term monitoring of flowering dates has been conducted by volunteers in alpine plant communities in the Taisetsu Mountains of northern Japan. The present study reports the results of analysis of 6 years of data (2006-2011) on flowering phenology. Time to first flowering of a species can be successfully expressed as the temperature sum above 5℃. In fellfield communities, cool temperatures restrict the development of floral buds. In the warmest summer, most of the fellfield species had the earliest onset flowering and the shortest flowering period. On the other hand, flowering of snowbed communities was strongly determined by snowmelt time at a local scale. The relationship between summer temperature and snowmelt time was less clear, indicating the difficulty in general prediction of snowmelt time. Slow snowmelt within a community in cool summers increased flowering overlap among species. Several species had significant variations in the thermal requirement for flowering between populations. Therefore, consideration of seasonal patterns of temperature, site-specific snowmelt patterns, and variation in ecophysiological traits of a species are important for precise prediction of global warming impacts on the phenology of alpine ecosystems.
Acheilognathinae is a subfamily of Cyprinidae that demonstrates a unique reproductive habit in which females lay eggs on the branchiae of fresh water bivalves, including the family Unionidae. Three species of Acheilognathinae -Tanakia limbata, T. lanceolata and Rhodeus ocellatus ocellatus- are distributed in Kagoshima Prefecture. It is noteworthy that the southern limit of the geographical distribution of T. limbata occurs in the northern part of the prefecture. Domestic Acheilognathinae species, including T. limbata, are exposed to the risks of competition and interspecific hybridization with alien species. Little information is available regarding the distribution of Acheilognathinae in Kagoshima Prefecture; therefore, we surveyed the distributions of Acheilognathinae and Unionidae in the area. T. limbata, R. o. ocellatus and T. lanceolata were collected during surveys on 16 rivers. Fishes suspected as hybrids of T. limbata and R. o. ocellatus were also found. Live individuals or empty shells of three Unionidae species, Pronodularia japanensis, Inversiunio reinianus yanagawensis and Anodonta woodiana, were collected. Acheilognathinae seemed to select particular Unionidae species; however, the occurrence of suspected hybrids suggests that this selectivity may be lost under specific conditions.
Many abandoned underground sites, such as war-related underground sites and abandoned mines, have been used by bats as roosting sites. However, these sites carry the risk of being closed for safety measures. To protect roosting sites of bats, some sites in Japan have been gated against human entrance. To date, few studies have assessed the impact of gating on resident bats. We investigated the effect of gating on a large colony of Miniopterus fuliginosus at an underground site in Chiba Prefecture. The number of Miniopterus fuliginosus at the site did not differ before and after construction of the bat gates. Our results demonstrated that the gates served as effective safety measures and did not negatively affect bats. Future studies should evaluate the effect of various gate structures on bats to optimize the application of bat gates at other underground sites.
The recent construction of wind-power plants in Japan has raised concerns about bird collisions, especially involving White-tailed Eagles, Haliaeetus albicilla, in Hokkaido, Japan. Although White-tailed Eagles are protected in Japan, no measures have been taken to prevent collisions. The major objectives of this report were (1) to examine trends and characteristics of White-tailed Eagle collisions with wind turbines based on an analysis of accident reports and some field investigations, and (2) to explore possible ecological and life history traits related to the collision of eagles with wind turbines. Twenty-seven White-tailed Eagle collisions occurred between Feb. 2004 and May 2011, in Hokkaido. Most of the fatalities involved immature White-tailed Eagles, including juveniles, and occurred from December to May, when both residents and winter migrant eagles are present in Hokkaido. This report emphasizes the need for measures to prevent collisions of White-tailed Eagles with wind turbines.
Interest in natural sources of renewable energy has risen in Japan. Several wind-power facilities have been built along the western coast of Hokkaido because of the excellent potential for wind energy. The impacts of the construction of wind-power facilities on coastal dune vegetation are not clear. In this paper, we review the existing research on the effects of wind-power generation on rare coastal dune grassland habitats on the Zenibako coast of Hokkaido. We identified permanent and temporary direct impacts. The disturbance of coastal dune vegetation was temporary, but the rate of vegetation loss can be critical. Changes in wind direction or the amount of sand movement can have important effects on dune vegetation. The social concern for the local natural environment was also important along the Zenibako coast. The government should consider these factors when selecting sites for renewable energy facilities.
Offshore wind-power generation is one of the fastest growing industries in many areas, especially Europe. Offshore wind farms (OWFs) can provide several economic benefits, but are potential threats to some marine organisms. Noises produced by exploration drilling and pile-driving during construction of OWFs can impede acoustic communication of fishes and marine mammals. Wind turbine bases with scour protection structures directly reduce the habitats of marine organisms and potentially affect their survival by altering oceanographic conditions and food availability. Collisions between turbines and flying birds have also been frequently observed at OWFs. Foraging seabirds and/or migratory terrestrial birds display avoidance responses to OWFs (e.g. detour flights around the turbines), and several researchers have modelled the additional energetic costs of such detour flights and potential impacts on the body condition of the birds. Further long-term studies are needed for various organisms at OWFs across a broad geographic distribution. Efforts to mitigate the impacts of OWFs on marine ecosystems should include the avoidance of OWF construction in areas harbouring important foraging areas and migratory routes, acoustic deterrence methods (e.g. bubble curtain) during construction, and turning off turbines during breeding and migrating seasons.
Currently, the conservation of biodiversity ranks alongside the regulation of global warming as the most important global environmental problems. Biological invasions are considered one of the most important causative agents of declines in biodiversity. Therefore, in Article 8 (h), the Convention on Biological Diversity (CBD) specified that each contracting party must undertake efforts to control alien species that threaten ecosystems, habitats, or species. Furthermore, the "Aichi Target," based on the 2010 targets identified during CBD's 10^<th> Conference of Parties (COP10, held at Nagoya, Japan), proposed as Target 9 that, "By 2020, invasive alien species and pathways are identified and prioritized, priority species are controlled or eradicated, and measures are in place to manage pathways to prevent their introduction and establishment." Because the need to control alien species has increased worldwide, each country needs to possess or prepare regulation systems against biological invasions. On the other hand, economic globalization has recently undergone rapid advances, which increases the chances of introductions and transportation of alien species. Japan has a large economy and is simultaneously a resource-poor country that is largely dependent on the importation of foods and natural resources from abroad. Therefore, our country can be considered to have a constant high risk of invasion by alien species. Of course, Japan has some quarantine systems and regulations to counter alien species. However, the risk of invasion by alien species continues to rise irrespective of efforts to prevent their arrival and establishment. The World Trade Organization (WTO) is confronting the control of alien species by applying immense diplomatic pressure.
Adaptive management has been applied to manage wild deer populations in Japan. Here, I present a strategic schema for implementing complete adaptive wildlife management. This schema consists of a hierarchical distribution comprising one policy and three layers (strategy, operation and tactics) of measures for wildlife management. The lower layers aim to achieve the goals of the higher layers. An important precondition of adaptive management is that every measure should be evaluated properly. For the evaluation, control conditions must be established for each measure, although these are rarely established in actual management programs. I propose an alternative method for evaluating multiple measures.