Japanese Journal of Conservation Ecology
Online ISSN : 2424-1431
Print ISSN : 1342-4327
Volume 26, Issue 2
Displaying 1-18 of 18 articles from this issue
Original Article
  • Haruka Iwasawa, Masayuki U.Saito, Ikuyo Saeki
    Article type: Original Article
    2021 Volume 26 Issue 2 Article ID: 2040
    Published: August 31, 2021
    Released on J-STAGE: December 31, 2021
    Advance online publication: August 31, 2021
    JOURNAL OPEN ACCESS
    Supplementary material

    Urbanisation is ongoing worldwide and has various effects on wildlife. The changes in mammal communities caused by urbanisation are important for biodiversity conservation because mammals are large, consume large amounts of energy, and tend to occupy higher positions in trophic webs than other species classes. Furthermore, in urban and rural landscapes, conflicts between mammals and humans, such as damage to agricultural crops or road kills, are increasing. The city of Tsukuba in Ibaraki Prefecture, Japan, is undergoing rapid urbanisation. Tsukuba is characterised by a large continuous forest around Mt. Tsukuba and highly fragmented forests in urban areas. This ecological setting allows us to examine the effects of urbanisation on mammal communities at a relatively small spatial scale. With this advantage, we used camera trap surveys to investigate the variation in mammal species composition, diversity, and diel activity from the foothills of Mt. Tsukuba to urbanised lowland areas. From July to November 2019, we conducted camera trap monitoring at 24 forest sites. At each site, a camera was set in a place with relatively little groundcover vegetation to maximise the consistency of detection rates. Camera data were collected monthly and the captured 15-second-long videos were analysed. The 24 sites were classified by forest continuity (continuous or fragmented), amount of vehicular traffic (high, medium, or low), and vegetation type (natural, semi-natural, or artificial). The relationships between these factors and the number of records per species were examined using a generalised linear model (GLM). The number of camera trap days per site averaged 81 and 525 video files of 10 mammal species were obtained. Wild boar (Sus scrofa), Japanese badger (Meles meles), Japanese marten (Martes melampus), and Japanese squirrel (Sciurus lis) were recorded mainly in continuous forests. Raccoon dog (Nyctereutes procyonoides), Japanese hare (Lepus brachyurus), and masked palm civet (Paguma larvata) were recorded in both fragmented and continuous forests. The common raccoon (Procyon lotor), an introduced species, was recorded only in fragmented forests. The GLM analyses revealed that forest continuity had significant positive effects on the number of records of wild boar and masked palm civet. The amount of vehicular traffic had significant negative effects on the number of records of wild boar and Japanese marten, but positive effects on those of raccoon dogs and common raccoons. Before the study, we expected that the presence of natural and semi-natural forests would have positive effects on the abundances of all mammals, but the common raccoon was captured significantly more frequently in artificial forests than in natural or semi-natural forests. Species accumulation curve analysis demonstrated that forest fragmentation markedly reduced native species richness. The diel activity patterns of raccoon dogs differed significantly with differences in forest continuity, amount of vehicular traffic, and vegetation type, whereas those of Japanese hare and masked palm civet did not. In summary, urbanisation strongly influenced species composition, diversity, and diel activity, but the response patterns varied considerably among species.

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  • Hitomi Yaguchi, Yoshinobu Hoshino
    Article type: Original Article
    2021 Volume 26 Issue 2 Article ID: 2039
    Published: August 31, 2021
    Released on J-STAGE: December 31, 2021
    Advance online publication: August 31, 2021
    JOURNAL OPEN ACCESS
    Supplementary material

    In this study, we investigated the influence of four vegetation management treatments (tree cutting, mowing and litter removal, removal of evergreen trees under the shrub layer, and abandonment) on the composition of plant and insect functional groups in Quercus serrata secondary forests on the Musashino Terrace, Japan. We performed a vegetation survey, monthly transect surveys, and an insect pitfall trap survey, and recorded 175 plant species and 271 insect species, which we then classified into eight plant functional groups (PFGs) and six insect functional groups (IFGs), respectively, using cluster analysis. Plant functional traits included Raunkiaer life form, leaf survival season, growth form, radicle form, pollination and seed dispersal syndromes, blooming season, fruiting season, and seed weight. PFGs were mainly classified according to seed dispersal and fruiting season. The PFG characterised by spring blooming and fruiting, small seeds, and hemicryptophytic form included herbaceous species that are typically found in managed secondary forests as well as many threatened species. Meanwhile, spring-blooming, deciduous plants included tree species typical of secondary forests, and endzoochorous evergreen trees included ornamental and garden trees. Insect functional traits included body size, larval feeding type, imago feeding type and season of imago appearance. IFGs were classified according to body size and larval feeding type. Among the IFGs, small folivores included Chrysomelidae and Symphyta; medium-sized herbivorous folivores (palynivores, nectivores, frugivores and xylophages) included Lycaenidae, Cerambycidae and Scarabaeidae; large folivores included Nymphalidae, Acrididae and Tettigoniidae; scavenging and dung-feeding insects included Scarabaeidae and Staphylinidae; and medium-sized insectivorous insects included Carabinae, Gryllidae and Vespinae. Ordination of the functional groups based on redundancy analysis indicated that PFGs were distributed along gradients of the forest floor environment, such as the number of fallen leaves accumulated on the ground surface and soil hardness, whereas IFGs were distributed along gradients of the tree layer environment, such as canopy openness. In terms of vegetation management effects, PFG composition was mainly influenced by mowing and litter removal, whereas IFG composition was mainly influenced by tree cutting and evergreen tree removal.

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  • Taiki Inoue, Toru Okamoto, Tanaka Kenta
    Article type: Original Article
    2021 Volume 26 Issue 2 Article ID: 2041
    Published: August 31, 2021
    Released on J-STAGE: December 31, 2021
    Advance online publication: August 31, 2021
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    Semi-natural grasslands contain high plant diversity, but they are declining worldwide. Understanding the causes of grassland decline requires clarifying changes in the total area and distribution of grasslands at the regional scale. Within Japan, previous studies have focused on grassland decline following World War II, when grassland resources were of limited anthropogenic value, and few studies have been conducted in high-elevation areas, despite the country’s complex topography. Therefore, we examined changes in the distribution of grassland areas in the Sugadaira Highlands, central Japan, over approximately 289 years (1722-2010). We quantified changes in the grassland area using topographic maps and aerial photography for the 130-year period of 1881-2010, and qualitatively estimated changes in grassland for the additional 159-year period of 1722-1881 using old maps. As of 1912, 85.3% (37.7 km2) of the total Sugadaira Highlands area was blanketed by a single continuous grassland. Records from 1722-1881 indicate that most of the study area was grassland during that period. However, by 2010, only 5.3 km2 of fragmented grassland remained. The rate of grassland decline was most rapid during the afforestation period of 1912-1937, and was more moderate during the period 1937-1947. The Sugadaira Highlands were designated a national park in 1947, after which the rate of grassland decline increased again. Relative to other areas of Japan, grassland decline in the study area has been particularly rapid. We determined no tendency of a reduced decline in grassland areas in national parks relative to the national average. To preserve biodiversity in these important landscapes, we must support natural grassland conservation and management.

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  • Norimasa Sugita, Atsushi Ebihara, Tsuyoshi Hosoya, Utsugi Jinbo, Masan ...
    Article type: Original Article
    2021 Volume 26 Issue 2 Article ID: 2038
    Published: August 31, 2021
    Released on J-STAGE: December 31, 2021
    Advance online publication: August 31, 2021
    JOURNAL OPEN ACCESS
    Supplementary material

    Most Japanese endangered species assigned to the Red List of the Ministry of the Environment lack biological data for practical conservation plans because it is difficult to collect specimens due to inaccessible habitats or small population sizes. Natural history museums store many specimens of extinct or endangered species. Specimens of endangered species stored in museums facilitate the collection of biological information such as species distributions and morphological and genetic data. However, because occurrence records of endangered species are dispersed over paper specimen catalogues or checklists, analyses based on more integrated data are necessary. In this study, we integrated the occurrence records of species ranked as Extinct, Extinct in the Wild, Critically Endangered, and Endangered on the Red List in Japan, into one accessible dataset based on specimen data. The data indicate that museums in Japan hold more than one specimen of 95.9% of endangered species, with at least 58,415 specimens preserved overall. Together with museums overseas, specimens of 97.0% of endangered species were confirmed. In total, there were more than 20 specimens of 26.5% of endangered species that would be suitable for estimates of genetic diversity within a population. These natural history specimens could be applied to various practical research endeavors, which would be useful for conservation efforts for endangered species. On the other hand, some incomplete data and sampling bias were observed in relation to collection taxa, sites, and date. Although staff at natural history museums in Japan have contributed to the digitalization of specimen data and the sharing of databases via the internet, we still need to improve the reliability and coverage of endangered species through systematic collection of such specimens, enhancement of the quality of specimen data, and continuous management of preserved specimens.

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  • Kosuke Takaku, Takahiro Morosawa
    Article type: Original Article
    2021 Volume 26 Issue 2 Article ID: 2109
    Published: October 31, 2021
    Released on J-STAGE: December 31, 2021
    Advance online publication: October 31, 2021
    JOURNAL OPEN ACCESS

    The trade in endangered native fishes for ornamental purposes is becoming popular in Japan. The recent growth in this trade has been reflected in the number of auctions, which has raised concern for wild populations. This study analysed the state and pattern of such trades using auction trade data for 184 endangered species on the Red List of the Ministry of Environment of Japan over a 10-year period. Most of the trade involved 10 species, of which the top three were Coreoperca kawamebari, Lates japonicus, and Acheilognathus typus. A cluster analysis of the data classified the trading pattern into eight subgroups, such as “main channel”, “low-margin high-volume”, and “high added value” species. High-volume trade based on captive-bred individuals was confirmed for several species of bitterling fishes (Cyprinidae: Acheilognathinae).

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Review
  • Takafumi Ohsawa
    Article type: Review
    2021 Volume 26 Issue 2 Article ID: 2110
    Published: October 31, 2021
    Released on J-STAGE: December 31, 2021
    Advance online publication: October 31, 2021
    JOURNAL OPEN ACCESS
    Supplementary material

    This study reviews and analyses challenges related to the post-2020 Global Biodiversity Framework (post-Aichi Biodiversity Targets) of the Convention on Biological Diversity, in terms of conserving genetic diversity and sharing the benefits of utilisation of genetic resources. The importance of establishing comprehensive targets and indicators for conserving the genetic diversity of all species, including wild species, is highlighted. The draft framework proposed maintenance of at least 90% of the genetic diversity within all species as the 2050 goal, and the use of population proportions with an effective population size > 500 as a headline indicator. These proposals could be improved to more easily communicable global targets and indicators by consideration of the numbers of mature individuals, subspecies and variants. Furthermore, indicators of genetic structure conservation could be developed by adopting pre-existing metrics such as evolutionarily significant units (ESUs) and management units (MUs). Ideally, at least one gene conservation unit (GCU) or similar protected natural area should be established within each ESU or MU to ensure protection of genetic diversity. The proportion of species meeting these requirements could be calculated to evaluate the progress of genetic structure conservation. For longer-term evaluations, targets and/or indicators could be developed to determine the extent to which genetic erosion is reducing species/population fitness. The draft framework has proposed a global goal and target to increase sharing of the benefits of genetic resource utilisation; however, this could lead to excessive exploitation of genetic resources that require multiple collection from the field. Ongoing discussions include identification of genetic resources distributed across international borders, the potential introduction of a new multilateral benefit-sharing mechanism for such genetic resources, and whether digital sequence information (DSI) should be included in the scope of this benefit sharing. Overall, more attention is being paid to benefit sharing in relation to the post-2020 Global Biodiversity Framework, rather than to the conservation of genetic resources and their diversity. Therefore, the global discussion should be further developed, based on a conservation-genetics framework, toward implementation of measures to conserve and sustainably use biodiversity.

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Report
  • Daisuke Shimizu, Yuji Yamazaki
    Article type: Report
    2021 Volume 26 Issue 2 Article ID: 2029
    Published: August 31, 2021
    Released on J-STAGE: December 31, 2021
    Advance online publication: August 31, 2021
    JOURNAL OPEN ACCESS

    Colias palaeno sugitanii is an alpine butterfly that inhabits the alpine to subalpine zones in the central mountains of the Japanese archipelago. Global warming has led to a decrease in its habitat and it was designated a near-threatened species in the 2019 Ministry of the Environment Red List. At present, however, there is insufficient basic ecological research on the habitats and life cycle of this species. To conserve Colias palaeno sugitanii, we conducted a survey in the highland moor at Midagahara (elevation 1600~2100 m) in the Tateyama Mountains, which is one of its main habitats. We recorded 529 adults between July 17 and August 18, 2019. This species was recorded from grassland over 1700 m and was not found in valleys or forests in the surveyed area. To evaluate factors determining the occurrence of this species in grassland, logistic regression analysis was conducted using environmental and topographical features. Site slope had a positive effect on its occurrence, while the presence of a pond had a negative effect. These results suggest that adults of this species tend to use well-drained grassland with relatively high slopes. We also investigated the species composition, morphological features, and habitat of the food and host plants used by Colias palaeno sugitanii. The results suggest that future environmental changes might lead to further declines in its population.

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  • Shohei Oumi, Yumiko Nagai, Noriko Iwai
    Article type: Report
    2021 Volume 26 Issue 2 Article ID: 2044
    Published: October 31, 2021
    Released on J-STAGE: December 31, 2021
    Advance online publication: October 31, 2021
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    Odorrana splendida is an endangered frog endemic to Amami-Oshima Island that is listed as a natural monument by the Kagoshima Prefecture government. While some studies have examined the ecology of adult O. splendida, few studies have examined its larvae. Therefore, this study examined larval drift by tracking fluorescently tagged larvae in a natural stream. We tagged 283 individuals, released them in a pool in the head stream, and tracked them for 2 years in 13 surveys at 1-3-month intervals. We divided the 303-m-long stream into 6-m-long sections and counted the number of larvae within each section. Over the 2 years, we found 9,642 individuals. Tagged larvae were found until day 736. The farthest drift distances from the release pool were 56-62, 62-68, and 128-134 m on days 29, 261, and 320-682, respectively. The estimated maximum drift distance did not vary markedly within a year, as it was 85.3 m on day 29 and 89.9 m on day 320. These results suggest that larval O. splendida in the stream studied drift as far as 130 m in a year and, typically, over 85-95 m. The drift distance did not extend much after day 29 and was not proportional to the corresponding time period. In addition, the proportion of tagged individuals remaining in the release pool increased as time passed. Our results suggest that while O. splendida tadpoles do drift from the original pool, the drift occurs during their early stage, during rare events, such as heavy rain. The survival rates of drifted larvae might be low or the drift rates of tadpoles downstream might be high. This study showed the need to consider the downstream environment as well as that around oviposition sites for conserving the habitat of O. splendida larvae.

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  • Katsushige Nomura, Reiko Nomura, Ichiro Tamaki, Satoshi Kikuchi
    Article type: Report
    2021 Volume 26 Issue 2 Article ID: 2024
    Published: August 31, 2021
    Released on J-STAGE: December 31, 2021
    Advance online publication: August 31, 2021
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    The Japanese red maple, Acer pycnanthum, is an endangered tree species found in hilly regions of Tokai District, Japan. The lack of successful natural recruitment in A. pycnanthum has generated increasing concern for its population-level persistence. Recently, we found abundant A. pycnanthum saplings on a reclaimed hillslope at a housing complex in Higashiyama in Gifu Prefecture. These saplings had seeded from a single female tree in the neighbouring forest and were thriving under improved light conditions. In this study, we examined the survival, reproductive condition, diameter at breast height (DBH) and tree height of these saplings to elucidate the regeneration traits of A. pycnanthum. All saplings on the reclaimed slope were distributed within a 50-m radius of the likely parent tree. Seedlings near the forest edge grew faster than those farther away; the factors contributing to this gradient remain unknown. DBH and tree height were highly correlated. Only four seedlings, all of which had DBH > 10 cm and tree height > 8 m, had ever flowered. Based on their shoot structure, we estimated that the three male saplings had a height of 8.9 m in their first flowering year. In contrast, the height of the single female sapling was approximately 10 m when it first flowered in 2020. These data suggest that males reach maturity earlier than females. The largest sapling flowered consecutively after reaching a height of 11 m. Because only two female trees currently remain in the neighbouring forest stand, new reproductive trees of both sexes will contribute to the long-term persistence of this population.

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  • Akira Matsui
    Article type: Report
    2021 Volume 26 Issue 2 Article ID: 2027
    Published: August 31, 2021
    Released on J-STAGE: December 31, 2021
    Advance online publication: August 31, 2021
    JOURNAL OPEN ACCESS

    Due to a postwar forestry expansion policy in Japan, upstream catchment areas are currently forested, and flow conditions are being homogenized by dam construction and river improvement. To document any adverse effects of this policy as well as hydraulic and water-utilization policies, it is important to monitor systems over the long term, such as the most recent 30 years of the postwar period. This report focuses on the Minami River, Fukui Prefecture, Japan. I estimate how changes in the river environment have affected the number of fish in the long term and propose crucial river development plans. Using the results of a national census along rivers, temporal changes in the fish communities of rivers with abundant fish fauna and populations were statistically analyzed. The biomass of Rhinogobius flumineus has increased, while those of Tribolodon hakonensis and Liobagrus reinii have significantly decreased in the Minami River. I hypothesize that an increase in the abundance of river runs led to the increase in Rhinogobius flumineus, whereas the reduced abundance of rapids and pools caused the decreases in Tribolodon hakonensis and Liobagrus reinii. A future river development plan is proposed to create additional rapids and pools in the Minami River.

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  • Hiroki Hata, Daisuke Togaki, Kota Ogasawara, Koji Matsumoto, Takahito ...
    Article type: Report
    2021 Volume 26 Issue 2 Article ID: 2111
    Published: October 31, 2021
    Released on J-STAGE: December 31, 2021
    Advance online publication: October 31, 2021
    JOURNAL OPEN ACCESS
    Supplementary material

    Pronodularia japanensis is a freshwater mussel (family Unionidae) endemic to Honshu, Shikoku and Kyushu in Japan. This unionid species prefers running water, and its main habitat is currently agricultural ditches. In this study, we report a newly found population of this species in an agricultural ditch in the alluvial Dozen Plain, in Ehime Prefecture, Japan. In Ehime, P. japanensis was previously recorded as inhabiting only the Matsuyama Plain and Uwa Basin, and its distribution area and density have been rapidly decreasing for decades; hence, this species is protected as endangered in Ehime Prefecture. We conducted a survey of an agricultural ditch in the Dozen Plain that was scheduled for rerouting during farmland consolidation. We found 651 P. japanensis individuals, with a maximum density of 20 individuals/m2, in an earthen ditch with a width of approximately 1 m and a length of 440 m. In total, 1,249 individuals were estimated to inhabit this earthen ditch. In a 60-m section where both revetments were covered with concrete, the density of P. japanensis was quite low. The mean shell length of P. japanensis was 41.7 ± 5.8 mm, and the standard deviation was larger than that of the Kunichi River population on the Matsuyama Plain. Therefore, the life span of the mussel in this earthen ditch is estimated to be shorter on average than in the Kunichi River, and reproduction occurs repeatedly. In the study area, although agricultural ditches for rice paddies form a network of aquatic habitats on the alluvial plain, most are concrete-covered due to previous farmland consolidation. Therefore, the earthen ditch examined here is one of the very few remaining in this area, and likely represents part of the last remaining habitat of unionid species. Pronodularia japanensis is listed as a near-threatened species in Japan, and conservation of the study population is necessary. Freshwater mussels are under threat of further decline due to anthropogenic influences; conservation of this species while also maintaining the adjacent agricultural field could serve as a good example for other areas.

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  • Seiki Takatsuki, Dai Nagamatsu
    Article type: Report
    2021 Volume 26 Issue 2 Article ID: 2042
    Published: October 31, 2021
    Released on J-STAGE: December 31, 2021
    Advance online publication: October 31, 2021
    JOURNAL OPEN ACCESS
    Supplementary material

    Rapidly expanding Sika deer populations in Japan are increasingly affecting forest vegetation. Deer populations have had particularly negative effects in Tottori Prefecture in western Japan, an area with extensive plantations of Cryptomeria japonica (Japanese cedar). We assessed understory conditions and damage to forest vegetation in both plantation and deciduous broad-leaved forests in this region. Fecal analyses indicated that living leaf tissue accounted for only 13.26% of the diet of the deer, even during the summer, and less nutritious materials including woody fiber, plant culms, and dead leaves comprised as much as 80%. Understory vegetation was in poor condition in both the plantation and deciduous broad-leaved stands. Deer exclusion fencing and subsequent assessments indicated that biomass indices were 9 and 39 times greater within the exclosure in the plantation and broad-leaved forest, respectively. Our results indicate that the diet of deer in areas dominated by Japanese cedar plantations is comprised largely of non-leaf plant material, even during the summer months, due to sparse understory vegetation.

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Practice Report
  • Shiro Tsuyuzaki, Masayuki Senzaki, Naoya Wada, Hajime Matsushima
    Article type: Practice Report
    2021 Volume 26 Issue 2 Article ID: 2104
    Published: October 31, 2021
    Released on J-STAGE: December 31, 2021
    Advance online publication: October 31, 2021
    JOURNAL OPEN ACCESS

    The Ecological Society of Japan submitted "The opinion for suspension of wind farm construction on the Zenibako Coast" to the Government of Hokkaido and the wind farm owner in 2011, reflecting concerns regarding the academic and ecosystem values of the proposed construction in the area. In addition, an Aftercare Committee (ACC) was established. However, the wind farm was constructed and became operational in February 2020. To evaluate the associated ecosystem impacts, the ACC completed landscape, vegetation and avifauna surveys on and adjacent to the wind farm in the summer of 2020. The surveys yielded four key results: (1) yards occupied 61% of the 5.5-ha footprint and soil erosion was prevalent along road slopes; (2) the greatest ecosystem alteration occurred in the grassland zone, as the wind farm was established nearly parallel to the coastline; (3) exotic plant species, especially Cakile edentula, have established and become widespread on roads and yard areas; and (4) avifaunal populations have declined and the community has become simplified.

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Scientific Proposal
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