Sasakia charonda, the giant purple emperor, is the national butterfly of Japan and has been designated a Red List species. To devise a forest management plan for the conservation of this species, we investigated habitat characteristics, the regeneration patterns of its host tree, Celtis sinensis, numbers of S. charonda larvae overwintering near the bases of host trees, and numbers of adults during the flight period, at two sites, Shimokomoriya (SK) and Isesaki (IS), near Mooka City, Tochigi Prefecture, in central Japan. Forests were more widely and more continuously distributed at SK than at IS and, at both sites, forests consisted of patches of secondary Pinus densiflora-Castanea crenata and Quercus serrata forests, as well as plantations of Quercus acutissima, Q. serrata, conifers and bamboo. Mature C. sinensis were distributed in small clusters at forest edges, near farmhouses, and in abandoned fields. The density of mature host trees (tree height: 2m or more) was higher in secondary P. densiflora-C. crenata and Q. serrata forests than in the other forest types, or elsewhere. The total number of trees was much higher at IS than at SK. Current or first-year seedlings were found at newly established forest edges, approximately one year after partial deforestation. At SK, the number of overwintering larvae per host tree was significantly higher for trees exceeding 25cm in diameter at breast height than for host trees in other size classes, while at IS, the number of larvae did not differ with host size. We found a significant positive correlation between the number of overwintering larvae and the total forested area, in addition to the area of secondary broadleaf deciduous forest (secondary P. densiflora-C. crenata and Q. serrata forests, and plantations of Q. acutissima and Q. serrata) within a 100-m radius of a host tree. More adult butterflies were recorded at SK than at IS, and most butterflies were observed near Q. acutissima plantations. Our results suggest that although partial deforestation of secondary broadleaf deciduous forests, and altered land use, has led to an increase in the density of host trees, it has decreased the densities of adult and overwintering larvae of S. charonda. To accommodate these contrasting habitat requirements that pertain between the butterfly and its host tree, it may be necessary to divide secondary broadleaf deciduous forests into blocks and to clear-cut these blocks in succession, at different times, without altering traditional land-use patterns.

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An unusual decline (withering causing death) of Prunus mume began in the late 1980s in orchards in Tanabe City and its environs, in Wakayama Prefecture, Japan. The decline ultimately involved ca. 10% of all P. mume trees by the mid 1990s. Eight disks were sampled from damaged 15- and 25-year-old trees from five sites in the northwestern part of Tanabe City (decline area), where the decline began early and was extensive. Eight disks from healthy trees were sampled from five sites in the southwestern part of Tanabe City and Hikigawa-cho (healthy area). The annual ring width was measured and heavy metal concentrations in the rings were analyzed. Simultaneously, the amount of heavy metals in aerosol that adhered to a vinyl chloride sheet over one year was measured at each site in both areas. The results suggested that the decline in the P. mume trees began in the 1990s, when the ring width decreased significantly as compared to healthy trees. In the affected trees, the five-year average heavy metal concentration tended to increase as compared to that of the healthy trees, and the difference was significant in the last five years of the 1990s. By contrast, the heavy metal concentration in the soil did not differ significantly in the two areas, although the aerosol deposits contained significantly more heavy metals in the affected area than in the healthy area. The remarkable decrease in the annual ring width and the increased heavy metal concentrations in the rings were characteristics of the affected P. mume that were due to the levels of heavy metals in the air.

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To propose conservation plans for the tiny dragonfly, Nannophya pygmaea RAMBUR, we investigated its habitat use in a paddy field at the bottom of a valley in the hill country around Kanazawa City, Ishikawa Prefecture, Japan. The field, which had an area of 1200m2 and was located at the top of a terraced paddy field, was plowed every spring but was not used for rice cultivation. There were four plant communities, corresponding to varying water levels on the ground, which was plowed annually. One of the four communities, which included annual plants, extended along the spring-fed hillside outside of the plowed area. Mature males primarily occupied Communities 1 and 2, and immature males and females were distributed in other terrestrial parts. The distribution of mature males was relatively similar, especially in Community 2, across the years investigated. Although emergence occurred in Community 2 every year, in Community 1, it was observed in 2002, but not in 2001 and may not in 2003. This yearly difference corresponded to the precipitation observed during the previous summer. Thus, the emergence from Community 1 may reflect larval survival, which probably depended on the degree and length of the dry period in relation to precipitation. Individuals that seemed to have dispersed from the paddy population were seen in several fallow fields up to 1.5km away from the paddy. Based on these results, we considered N. pygmaea to be an opportunistic species that has adapted to small temporary marshes. We propose a conservation plan for N. pygmaea that incorporates creating biotope networks by plowing abandoned paddy fields.

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Formosan squirrels (Callosciurus erythraeus) were introduced to Kanagawa Prefecture, Japan, in the 1950s. During the past 52 years, they have become established in fragmented suburban forests, and their distribution area has expanded to 304km^2. The population dynamics of this expansion process were analyzed. Since reproductive females have exclusive home ranges, the distribution area of females was expected to be positively correlated with the number of females. Population parameters were calculated from 7 years of mark-recapture data. The observed expansion curve of their distribution area fits well with the predicted line of an exponential population growth model.

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The purpose of this study was to reveal the factors of shoreline vegetation decline and their relative importance. To accomplish this, we analyzed the relationship of vegetation decline over the last three decades with the environmental variables in Lake Kasumigaura (Nishiura). To quantify the decline, the vegetation zone width at right angles to the levee was measured at 122 points along the lakeshore at intervals of approximately one kilometer on vegetation maps produced in 1972, 1982, and 1997. The rate of decrease of the submerged and emerging vegetation zone widths from 1972 to 1982 and the rate of decrease of the emerging vegetation zone widths from 1982 to 1997 were calculated at each measured point. Stepwise linear regression was used to investigate the influence that certain environmental parameters (such as levee position, littoral slope, wave height, sediment particle size, distance from tributary mouth, and submerged vegetation zone width) would have as explanatory variables for the decrease rate. For both periods, levee position and littoral slope significantly accounted for the spatial variation in the rate of decrease of emerging vegetation; therefore, the emerging vegetation zone would decrease remarkably at points of steep littoral slope and/or offshore levee position. The submerged vegetation zone width in 1972 had a significant effect on the decrease rate of the emerging vegetation zone width between 1972 and 1982, and thus the emerging vegetation zone would decrease remarkably at points with a narrow submerged vegetation zone width. The environmental factors used in the analysis did not, however, sufficiently account for the pattern of decline of the submerged vegetation zone.

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In the spring and summer of 2003, we searched rural areas in Atsuma-cho and Mukawa-cho, Yufutsu-gun, Hokkaido, Japan, for nests of Bombus terrestris, an introduced agricultural pollinator that is suspected of becoming naturalized in the region. In 18 person-days, we found eight B. terrestris nests and 11 nests of native species. Most nests were found on the dikes at the edges of paddies and other cultivated fields. There was a high similarity in the nest sites used by B. terrestris, B. hypocrita sapporensis and B. dicersusu tersatus. Moreover, we witnessed some B. terrestris workers entering and leaving a B. hypocrita sapporensis nest. The close interspecific contact at the same nest suggests the possibility of parasite transmission between the species.

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The knowledge and technologies accumulated in the field of conservation ecology should, in pursuit of its practical mission of biodiversity conservation, be reflected in the political decision-making that turns the wheels of society. This article compares the historical background and current status of legislative developments and operations regarding national conservation policies between Japan and the United States as they relate to the conservation of endangered species, control of alien species, and biosafety of genetically modified organisms. The backlash against the loss of ecological integrity owing to the massive resource exploitation of the Western frontier has fostered a conservation philosophy and civic movement in the United States. Biologists, aware of the value of biodiversity, promoted the early development of nature and biodiversity conservation policies in the nation. Industrial circles with strong interests in the economic value of biodiversity also influenced the American biodiversity policy. While the United States has not ratified the Convention of Biological Diversity thus far, Japan, on the other hand, signed the Convention in 1993, triggering the Japanese government to belatedly tackle issues of biodiversity conservation from a national perspective. It is premature to evaluate Japan's legislation developed over the past decade regarding biodiversity conservation. However, in view of the rapid decline of biodiversity throughout the nation, academic achievements in conservation ecology are expected to effectively contribute to social practices through greater political assertiveness and improved social competence.

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We found a new population of an endangered species, Pinus armandii var. amamiana, in the Kinari National Forest along the Waseda River on Tanega-shima Island in southwestern Japan. This population is a 43-year-old secondary forest. A 2-ha area contained 138 surviving P. armandii var. amamiana trees over 2.0m tall, although no seedlings were found. The calculated population density of 69 trees/ha is the highest yet reported. Previously, an estimated 100 P. armandii var. amamiana trees were thought to exist on Tanega-shima Island, but based on this new evidence, the number should be revised. Some dead P. thunbergii and P. armandii var. amamiana trees, which were probably damaged by pine wilt disease, were found in and near this population. We have submitted an appeal to the Kyushu Regional Forest Office of the Forestry Agency, with the aim of establishing a new Protected Forest to preserve the genetic resources within the Kinari National Forest on Tanega-shima Island. We also suggest that measures be taken to counter pine wilt disease in and near this population.

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Population growth rate has been used as an index for assessing the ecological risk of toxic chemicals. However, the survival of young fish is difficult to estimate, and obtaining an accurate value for the rate of population growth is problematic. In order to focus on toxic chemicals, we defined decreases in population growth rate (Δγ), calculated using an age-structured model, as a measure of ecological risk. The measure Δγ is robust to the errors in juvenile fish survival estimates, and depends on the toxic effects of chemicals in relation to aspects of life history, such as decreased survival and fecundity. The index Δγ has the following advantages: (1) risks to organisms with different life histories can be compared, (2) the effects on different life stages, such as fertilization, hatching or larval survival can be evaluated, (3) Δγ is robust to measurement errors in life history parameters, and (4) Δγ can be used to assess the effects of harvesting. The measure Δγ can be applied not only to fish populations but also to other wildlife populations. Demographic parameters for age-structured models were extrapolated from empirical data on other species, and included data on age-specific fecundity, maturation age, maximum age, and mortality rate. We tested this approach for bluegill (Lepomis macrochirus), and for the extrapolation model.

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From June to September, 2003, we searched rural areas (7.75km^2) in Mukawa, Atsuma, and Monbetsu, in the Hidaka region of southern Hokkaido, for natural nests of alien (Bombus terrestris L.) and native Japanese bumblebee species. Twentyseven nests were found. Eight B. terrestris nests had been made in abandoned rodent nests underground. The number of individuals (i.e., eggs, larvae, cocoons, adults), and nest characteristics, such as food storage and the number of excretions, were recorded for nine of the 27 nests. The B. terrestris colonies contained a mean of 110 new queens; this mean is 4.4 times larger than the mean for native bumblebees. This strongly suggests that the reproductive ability of B. terrestris is higher than that of the native bumblebees in the region.

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The riparian forest in Hosomidani Valley, located in the West Chugoku Mountains, in western Japan, is facing an environmental crisis because of a major on-going forest road construction project undertaken by the Japan Green Resources Agency. Most of the original vegetation in Chugoku district has already been lost due to industrial activity, and the Hosomidani area is one of the few areas where precious habitat has been maintained. Researchers and NGOs jointly investigated the area and discovered many species in different taxa in Hosomidani that are listed in the Red Data Book (RDB). It is urgently important to protect these species and their habitat and to maintain the biodiversity of the Hosomidani area.

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