詳細

早坂　大亮 （ハヤサカ　ダイスケ）

  • 農学部 環境管理学科　准教授
Last Updated :2024/04/23

コミュニケーション情報 byコメンテータガイド

  • コメント

    企業（日本工営㈱）や国研（国立環境研）での経験を元に、生物多様性を損失させる原因の探索と影響の評価、その後の対策まで網羅的に研究しています。「ことの真実」は現場にしかありません。

  • 報道関連出演・掲載一覧

    ＜報道関連出演・掲載一覧＞ ●2024/1/15 　NHK奈良「ならナビ」 　殺虫剤と水田の水温上昇がトンボ類に与える影響を解明した研究について ●2023/6/19 　読売新聞（奈良版） 　大和川の水質改善について

研究者情報

学位

  • 博士（学術）（2006年03月 横浜国立大学）

ホームページURL

科研費研究者番号

  • 20583420

J-Global ID

プロフィール

  • 平成18年3月　　横浜国立大学大学院環境情報学府 環境生命学専攻博士課程後期 修了（指導教授：藤原一繪）
    平成18年4月～平成22年3月　　日本工営株式会社（建設コンサルタント企業）
    平成22年4月～平成22年9月　　九州産業大学工学部 非常勤講師（受入：内田 泰三）
    平成22年4月～平成25年3月　　独立行政法人国立環境研究所 生物・生態系環境研究センター 特別研究員（受入：五箇 公一）
    平成25年4月～平成31年3月　　近畿大学農学部 環境管理学科 講師
    平成31年（令和元年）4月～　　同 准教授

研究キーワード

  • 生態リスク評価   環境影響評価   生物侵入 / 外来種   生態系管理   生態毒性学   生態学   生物間相互作用   気候変動 / 温暖化   

現在の研究分野（キーワード）

    企業（日本工営㈱）や国研（国立環境研）での経験を元に、生物多様性を損失させる原因の探索と影響の評価、その後の対策まで網羅的に研究しています。「ことの真実」は現場にしかありません。

研究分野

  • ライフサイエンス / 多様性生物学、分類学
  • 環境・農学 / 化学物質影響 / 農薬曝露評価
  • 環境・農学 / 放射線影響 / 農薬曝露評価
  • 環境・農学 / 自然共生システム / 生態系影響解析
  • 環境・農学 / ランドスケープ科学
  • 環境・農学 / 環境農学
  • ライフサイエンス / 生態学、環境学

所属学協会

  • 日本応用動物昆虫学会   日本環境動物昆虫学会   Entomological Society of America (ESA)   日本農薬学会   日本雑草学会   British Ecological Society   日本緑化工学会   日本生態学会   The Association for Tropical Biology and Conservation   植生学会   

研究活動情報

論文

  • Ishiwaka N; Hashimoto K; Hiraiwa MK; Sánchez-Bayo F; Kadoya T; Hayasaka D
    Environmental Pollution 341 122831  2024年01月 [査読有り]
  • Hayasaka D; Kato K; Hiraiwa MK; Kasai H; Osaki K; Aoki R; Sawahata T
    Scientific Reports 13 21119  2023年11月 [査読有り]
     
    Abstract Invasive ants pose a risk to human well-being and social/ecosystem stability. Linepithema humile Mayr is among the most damaging invasive ants worldwide. Most L. humile populations invade ports/wharfs isolated from surrounding landscapes, but unfortunately, a new population was discovered in an inland urban area (Nara Prefecture) of Japan in 2021. In this study, first, the supercolony type of the Nara L. humile population was identified via a hostility test, and then its distribution pattern was characterized. In aggression tests between L. humile from Nara and four supercolonies (haplotypes LH1, LH2, LH3, LH4), this ant showed extremely strong hostility against all supercolonies exept LH2, which was detected only in Japan in its introduced range. In Nara, L. humile was abundant in and around the urban river. Simulations revealed that using this environment for movement/dispersal increased the annual dispersal ability by 14 times compared with that achieved via ground (125 m), as mentioned in the literature. Therefore, river channels can serve as major pathways of long-distance dispersal for L. humile invading inland urban areas. Since applying chemical strategies around rivers is problematic, preventing L. humile from moving to rivers from initial invasion sites is crucial.
  • Global warming intensifies the interference competition by a poleward-expanding invader on a native dragonfly species
    Nagano N; Hiraiwa MK; Ishiwaka N; Seko Y; Hashimoto K; Uchida T; Sánchez-Bayo F; Hayasaka D
    Royal Society Open Science 10 11 230449  2023年11月 [査読有り]
  • Sunamura E; Yamahara M; Kasai H; Hayasaka D; Suehiro W; Terayama M; Eguchi K
    Applied Entomology and Zoology 59 71 - 76 2023年10月 [査読有り]
  • 黒田有寿茂; 中濵直之; 早坂大亮; 玉置雅紀; 花井隆晃
    保全生態学研究 28 1 199 - 212 2023年05月 [査読有り]
  • Effects of salinity, temperature, and immersion conditions on seed germination of invasive Spartina alterniflora Loisel (smooth cordgrass) in Japan
    Matsuda R; Yamada K; Hayasaka D; Henmi Y
    Regional Studies in Marine Science 57 102738  2022年11月 [査読有り]
  • Hayasaka D; Hiraiwa MK; Maebara Y; Seko Y
    Journal of Pesticide Science 47 4 208 - 212 2022年10月 [査読有り]
  • Ecological characteristics of plants invading/colonizing street tree bases
    Furuno M; Uchida T; Huan XJ; Hayasaka D; Arase T
    Journal of Environmental Information Science 2022 1 12 - 23 2022年09月 [査読有り]
  • Kasai H; Hayasaka D; Sawahata T
    Zootaxa 5168 3 332 - 349 2022年07月 [査読有り]
  • Yugo Seko; Naoto Ishiwaka; Yuki Morikawa; Daisuke Hayasaka
    Entomological News in press  2022年 [査読有り]
  • Koya Hashimoto; Daisuke Hayasaka; Yuji Eguchi; Yugo Seko; Ji Cai; Koichi Goka; Taku Kadoya
    bioRxiv 2021年12月 
    AbstractRecent studies have uncovered that biotic interaction strength varies over time in real ecosystems intrinsically and/or responding to anthropogenic disturbances. Little is known, however, about whether such interaction variability strengthens or weakens community resistance against disturbances. Here, we examine how the change in interaction strength after pesticide application mediates disturbance impacts on a freshwater community using outdoor mesocosms. We show that the change in interaction strength buffered the disturbance impact but amplified it once the disturbance severity exceeded a certain threshold. Importantly, we also show that interactions fluctuating more temporally under no disturbances were more changeable in response to pesticide applications. Our findings suggest that a severe disturbance may have a surprise impact on a biological community amplified by their own interaction variability, but the possibility still remains that we can predict the consequences of the disturbance by measuring the interaction variability before the disturbance occurs.
  • Hayasaka D; Nakamori T; Tamaue K; Seko Y; Hashimoto K; Sawahata
    Journal of Economic Entomology 114 6 2460 - 2465 2021年12月 [査読有り]
     
    Abstract Strategic responses to invasive Latrodectus widow spiders are a global challenge due to the risks they pose to health and ecosystems. Chemical strategies involving the use of pyrethroids are effective against adult spiders, but as their populations rebound, chemical control becomes costly and unsustainable for eradication. A major obstacle is the inefficacy of insecticides against eggs, which are covered by a protective silk egg sac. Eradication of invasive spiders must focus on destroying progeny. Here, the responses of eggs in egg sacs of two invasive Latrodectus spiders in Japan (Latrodectus hasseltii (Thorell) and Latrodectus geometricus (C.L. Koch)) to short-term dry-heat exposure were examined. To test whether the dry-heat tolerance of the egg sacs of both spider species differed, lethal temperature (LT) was determined based on the hatching rate of eggs from egg sacs subjected to a range of temperatures. Hatching in both species failed completely when the egg sacs were exposed to temperatures of 55°C and above for 10 min, but the LT to reduce hatching by 90% (LT90) differed significantly between L. hasseltii (50. 9°C) and L. geometricus (52. 8°C). Our study highlights the efficacy of dry heat in suppressing hatching and thus shows the possibility for effective extermination of these noxious invasive pests. Further exploration and investigation of the effects of humidity and heat exposure time on egg sacs under field conditions are needed to guide Latrodectus spider control strategies.
  • 屋上緑化の多面的機能－飛来種子の捕捉による都市の生物多様性の向上－
    吉野正章; 横山晴菜; 早坂大亮; 内田泰三
    日本緑化工学会誌 47 1 171 - 174 2021年09月 [査読有り]
  • Iida K; Hayasaka D; Suzuki Y; Uchida T; Sawahata T; Hashimoto K
    Ecology and Evolution 11 13 9110 - 9122 2021年05月 [査読有り]
  • Furuno M; Uchida T; Hayasaka D; HUan XJ; Arase T
    International Journal of GEOMATE 20 81 153 - 161 2021年05月 [査読有り]
  • 澤畠拓夫; 小坂 彰; 瀬古祐吾; 早坂大亮
    ランドスケープ研究 84 5 683 - 686 2021年05月 [査読有り]
  • Seko Y; Nakahama N; Sawahata T; Hayasaka D
    BioInvasions Records 10 2 467 - 476 2021年02月 [査読有り]
  • Seko Y; Hashimoto K; Koba K; Hayasaka D; Sawahata T
    Scientific Reports 11 1 2874  2021年02月 [査読有り]
     
    The Argentine ant, Linepithema humile Mayr, has spread to almost all continents. In each introduced region, L. humile often forms a single large colony (supercolony), the members of which share the haplotype "LH1", despite the presence of other supercolonies with different genetic structures. However, the mechanisms underlying the successful invasion of LH1 ants are unclear. Here, we examined whether diet breadth differs between more successful (LH1) and less successful (LH2, LH3, LH4) L. humile supercolonies in Japan to better understand the processes responsible for invasion success. The standard ellipse areas (SEAs) of δ13C and δ15N and their ranges (CR and NR) were used as diet breadth indices. The SEAs of LH1 were much larger than those of the less successful supercolonies despite no differences in the baseline SEAs of arthropods within the supercolony habitats, indicating that the invasion success of a supercolony is associated with its diet breadth. Furthermore, LH1 had a broader CR than the other supercolonies, suggesting that which might be derived from superior resource exploitation ability. Our study highlights the importance of focusing on intraspecific differences in diet breadth among supercolonies when assessing organisms that can potentially invade and become dominant in new habitats.
  • Differences in bifenthrin and fipronil susceptibility among invasive Latrodectus spp. and nontarget spiders in Japan
    Hayasaka D; Numa T; Sawahata T
    Journal of Economic Entomology 114 1 257 - 264 2021年02月 [査読有り]
  • 河川水辺の国際調査結果を用いた九州の一級水系における河川環境、とくに外来植物群落の変遷に関する考察
    友口勇生; 内田泰三; 早坂大亮
    日本緑化工学会誌 46 1 186 - 189 2020年09月 [査読有り]
  • Maebara Y; Tamaoki M; Iguchi Y; Nakahama N; Hanai T; Nishino A; Hayasaka D
    Frontiers in Plant Science 11 556039  2020年08月 [査読有り]
     
    Among invasive species, aquatic plants pose serious threats to local biodiversity and ecosystem functions. Spartina alterniflora Loisel. (Poaceae), native to the eastern United States, was introduced unintentionally into Japan (Aichi and Kumamoto Prefectures) at around 2010. This invasive species could easily and rapidly spread to estuarine areas of Japan via vigorous trade and transport, making the prediction of its future invasion necessary. Here, the distribution and structure of the genetic variation of S. alterniflora in Japan were examined using chloroplast DNA (cpDNA) and microsatellite genotyping analyses for clarifying its invasion route and process. According to the cpDNA analysis, S. alterniflora populations in Japan had a single haplotype (haplotype C4) that is the most dominant genotype around the Florida Peninsula, the region of its origin, and is also widely found in the introduced populations in the East Asia. Microsatellite analysis also showed a loss of genetic diversity in Japanese S. alterniflora populations (allelic richness (A R) = 1.20-1.39) compared with that in its native region (A R = 4.58-4.59), suggesting a founder effect on S. alterniflora that might have occurred after invasion of the species into Japan. The principal coordinate analysis and The STRUCTURE analysis indicated that no gene mixing among Japanese local populations (Aichi, northern and southern Kumamoto) was observed, indicating that Spartina invasion occurred independently into these regions. Among the three regions, trading between the ports of northern Kumamoto and the U.S. was obviously lower than trading with China. We concluded that invasive S. alterniflora might have independently invaded Japan at different times through an East Asia route, particularly via China (i.e., secondary introduction). Therefore, it is important to strengthen the quarantine control on the importation of commodities, especially of transport vehicles at potential donor spots (i.e., border control/border biosecurity system), and to share information networks on invasive species between each region/port for minimizing further risks of biological species such as Spartina.
  • 中森拓也; 澤畠拓夫; 早坂大亮
    ペストロジー 35 1 19 - 21 2020年03月 [査読有り]
  • Hashimoto K; Kasai A; Hayasaka D; Goka K; Hayashi TI
    Ecological Indicators 113 106227  2020年02月 [査読有り]
  • Seed germination characteristics of invasive Spartina alterniflora Loisel in Japan: implications for its effective management
    Hayasaka D; Nakagawa M; Maebara Y; Kurazono T; Hashimoto K
    Scientific Reports 10 2116  2020年02月 [査読有り]
  • 2017年鹿児島県口永良部島の鳥類調査 -1970年代調査から40年を経過して-
    高塚星花; 飯田恭平; 橋本洸哉; 松谷実璃; 澤畠拓夫; 早坂大亮
    日本鳥学会誌 68 2 357 - 365 2019年10月 [査読有り]
  • Hashimoto K; Eguchi Y; Oishi H; Tazunoki Y; Tokuda M; Sanchez-Bayo F; Goka K; Hayasaka D
    Ecological Applications 29 6 e01945  2019年07月 [査読有り]
  • Uchida T; Arase T; Sato Y; Hayasaka D
    International Journal of GEOMATE 16 58 116 - 123 2019年06月 [査読有り]
  • 西野惇志; 前原 裕; 橋本洸哉; 内田泰三; 早坂大亮
    日本緑化工学会誌 44 4 596 - 605 2019年05月 [査読有り]
  • Nakahama N; Maebara Y; Seko Y; Iida K; Sawahata T; Hayasaka D
    Entomological News 128 3 217 - 225 2019年03月 [査読有り]
     
    Linepithema humile is one of the most damaging invasive species worldwide. Although chemical control strategies have proven effective for L. humile, the susceptibility of these invasive ants to the insecticide fipronil differs markedly among genetically different supercolonies. In Japan, five mitochondrial L. humile haplotypes were identified from eleven prefectural regions and cities as of 2010. In 2012, a new population was found in Okayama Prefecture. Here, we analyzed mitochondrial DNA from L. humile workers from the Okayama population to better understand the genetic structure of ants in Japan and develop effective control strategies. According to COI-COII and cytochrome b gene sequences, the L. humile Okayama population haplotype was consistent with the 'Japanese main' supercolony-the most invasive supercolony worldwide. Hence, we believe that the Okayama population (Japanese main supercolony) can be easily eradicated because of its early invasion stage, relatively limited distribution range and high sensitivity to fipronil.
  • Hayasaka D; Kobashi K; Hashimoto K
    Ecotoxicology and Environmental Safety 175 272 - 281 2019年03月 [査読有り]
  • Hayasaka D; Fujiwara S; Uchida T
    Jounrl of Integrative Agriculture 17 8 1881 - 1887 2018年08月 [査読有り]
  • Seko Y; Hayasaka D; Fujita T; Nishino A; Uchida T; Sánchez-Bayo F; Sawahata T
    Journal of Economic Entomology 111 1 319 - 326 2018年 [査読有り]
     
    The Argentine ant, Linepithema humile (Mayr Hymenoptera: Formicidae), is one of the world's most hazardous invasive species, and thus its eradication from Japan is important. Physical and chemical controls can be expensive and cause strong adverse effects on local terrestrial ecosystems regardless of their high efficacy. Here, presence/ absence of host-tree selection by Argentine ants was investigated to understand the ant-honeydew-producing insects interactions in order to develop new cultural controls compatible with biodiversity conservation. Abundance of Argentine ants and their tree utilization ratio was measured among dominant roadside trees (Cinnamomum camphora, Myrica rubra, Nerium indicum, Rhaphiolepis indica var. umbellata, Juniperus chinensis var. kaizuka) in two areas around Kobe, Japan. Almost all ants collected were Argentine ants suggesting that native ants would have been competitively excluded. Tree utilization of Argentine ants clearly differed among host trees. Abundance of both Argentine ants and honeydew-producing insects and tree utilization rate of the ants were significantly lower in especially C. camphora and J. chinensis. Few Argentine ants were observed trailing on C. camphora, J. Chinensis, and N. indicum, most probably due to low abundance of honeydew-producing insects on these trees with the toxic and repellent chemical components. On the other hand, high abundance of both Argentine ants and homopterans were found in M. rubra and especially R. indica. We suggest that reductions of R. indica and M. rubra would lead to a decrease in abundance of honeydew-producing insects, and thus effectively control populations of Argentine ants. At the same time, planting of C. camphora, J. Chinensis, and N. indicum may also play a role in restraint efficacy against invasion of the invasive ants.
  • Kobashi K; Harada T; Adachi Y; Mori M; Ihara M; Hayasaka D
    Ecotoxicology and Environmental Safety 138 122 - 129 2017年04月 [査読有り]
     
    There are growing concerns about the impacts of neonicotinoid insecticides on ecosystems worldwide, and yet ecotoxicity of many of these chemicals at community or ecosystem levels have not been evaluated under realistic conditions. In this study, effects of two neonicotinoid insecticides, imidacloprid and dinotefuran, on aquatic insect assemblages were evaluated in experimental rice mesocosms. During the 5-month period of the rice-growing season, residual concentrations of imidacloprid were 5-10 times higher than those of dinotefuran in both soil and water. Imidadoprid treatment (10 kg/ha) reduced significantly the populations of Crocothemis servilia inariannae and Lyriothemis pachygastra nymphs, whereas those of Orthetrwn afbistylum speciosum increased slightly throughout the experimental period. However, Notonecta uiguttata, which numbers were high from the start, later declined, indicating possible delayed chronic toxicity, while Guignotus japonicus disappeared. In contrast, dinotefuran (10 kg/ha) did not decrease the populations of any species, but rather increased the abundance of some insects, particularly Chironominae spp. larvae and C. servllia mariannoe nymphs, with the latter being 1.7x higher than those of controls. This was an indirect effect resulting from increased prey (e.g., chironomid larvae) and lack of competition with other dragonfly species. The susceptibilities of dragonfly nymphs to neonicotinoids, particularly irnidadoprid, were consistent with those reported elsewhere. In general, imidacloprid had higher impacts on aquatic insects compared to dinotefuran.
  • Uchida T; Tanaka J; Kondo K; Hayasaka D; Tomoguchi Y; Arase T; Okano T
    International Journal of GEOMATE 12 32 114 - 120 2017年04月 [査読有り]
     
    Alien species in the family Poaceae play an important role as cover plants for erosion control on slopes, particularly in Japan. However, concerns have arisen regarding the adverse effects of these species on the local ecosystem and biodiversity. This study therefore examined the succession and seed propagation of alien Poaceae that are used for erosion control on the cut slopes of Sakurajima volcano in southwestern Japan. The results were as follows: Although the alien species used as cover plants were dominant for the first couple of years following their introduction to the slopes, they were displaced entirely by native species after the sixth year, which is considerably faster than ordinary succession. In addition, heading (flowering) of alien species was also rarely observed in this period. It is considered that the observed results were caused by the oligotrophic conditions of the slopes on Sakurajima volcano.
  • Sánchez-Bayo F; Goka K; Hayasaka D
    Frontiers in Environmental Science 4 71  2016年11月 [査読有り]
     
    The widespread use of systemic neonicotinoid insecticides in agriculture results first in contamination of the soil of the treated crops, and secondly in the transfer of residues to the aquatic environment. The high toxicity of these insecticides to aquatic insects and other arthropods has been recognized, but there is little awareness of the impacts these chemicals have on aquatic environments and the ecosystem at large. Recent monitoring studies in several countries, however, have revealed a world-wide contamination of creeks, rivers and lakes with these insecticides, with residue levels in the low μg/L (ppb) range. The current extent of aquatic contamination by neonicotinoids is reviewed first, and the findings contrasted with the known acute and chronic toxicity of neonicotinoids to various aquatic organisms. Impacts on populations and aquatic communities, mostly using mesocosms, are reviewed next to identify the communities most at risk from those that undergo little or no impact. Finally, the ecological links between aquatic and terrestrial organisms are considered. The consequences for terrestrial vertebrate species that depend mainly on this food source are discussed together with impacts on ecosystem function. Gaps in knowledge stem from difficulties in obtaining long-term experimental data that relates the effects on individual organisms to impacts on populations and ecosystems. The paper concludes with a summary of findings and the implications they have for the larger ecosystem.
  • Vegetation succession on cut slopes covered with exotic grassess for erosion control, Mt. Sakurajima
    Kondo K; Uchida T; Hayasaka D; Tanaka J; Sato A; Arase T
    International Journal of GEOMATE 11 23 2136 - 2142 2016年06月 [査読有り][招待有り]
  • Kasai A; Hayashi TI; Ohnishi H; Suzuki K; Hayasaka D; Goka K
    Scientific Reports 6 23055  2016年03月 [査読有り]
     
    Several reports suggested that rice seedling nursery-box application of some systemic insecticides (neonicotinoids and fipronil) is the cause of the decline in dragonfly species noted since the 1990s in Japan. We conducted paddy mesocosm experiments to investigate the effect of the systemic insecticides clothianidin, fipronil and chlorantraniliprole on rice paddy field biological communities. Concentrations of all insecticides in the paddy water were reduced to the limit of detection within 3 months after application. However, residuals of these insecticides in the paddy soil were detected throughout the experimental period. Plankton species were affected by clothianidin and chlorantraniliprole right after the applications, but they recovered after the concentrations decreased. On the other hand, the effects of fipronil treatment, especially on Odonata, were larger than those of any other treatment. The number of adult dragonflies completing eclosion was severely decreased in the fipronil treatment. These results suggest that the accumulation of these insecticides in paddy soil reduces biodiversity by eliminating dragonfly nymphs, which occupy a high trophic level in paddy fields.
  • Uchida T; Furuno M; Minami T; Yamashita S; Uchiyama T; Arase T; Hayasaka D
    International Journal of GEOMATE 9 1 1353 - 1359 The GEOMATE International Society 2015年09月 [査読有り]
  • Hayasaka D; Kuwayama N; Takeo A; Ishida T; Mano H; Inoue MN; Nagai T; Sanchez-Bayo Francisco; Goka K; Sawahata T
    Ecotoxicology 24 6 1221 - 1228 2015年08月 [査読有り]
     
    Fipronil is one of the most effective insecticides to control the invasive ant Linepithema humile, but its effectiveness has been assessed without considering the genetic differences among L. humile supercolonies. We hypothesized that the susceptibility of the ant to fipronil might differ among supercolonies. If so, dosage and concentration of fipronil may need to be adjusted for effective eradication of each supercolony. The relative sensitivities of four L. humile supercolonies established in Hyogo (Japan) to fipronil baits were examined based on their acute toxicity (48-h LC50). Toxicities of fipronil to seven ground arthropods, including four native ant species, one native isopoda, and two cockroaches were also determined and compared to that of L. humile supercolonies using species sensitivity distributions. Marked differences in susceptibility of fipronil were apparent among the supercolonies (P < 0.008), with the 'Japanese main supercolony' (271 mu g L-1) being five to ten times more sensitive to fipronil than other colonies (1183-2782 mu g L-1). Toxicities to non-target species (330-2327 mu g L-1) were in the same range as that of L. humile, and SSDs between the two species groups were not significantly different (t = -1.389, P = 0.180), suggesting that fipronil's insecticidal activity is practically the same for L. humile as for non-target arthropods. Therefore, if the invasive ant is to be controlled using fipronil, this would also affect the local arthropod biodiversity. Only the 'Japanese main supercolony' can be controlled with appropriate bait dosages of fipronil that would have little impact on the other species.
  • Inoue MN; Saito-Morooka F; Suzuki K; Nomura T; Hayasaka D; Kishimoto T; Sugimaru K; Sugiyama T; Goka K
    Applied Entomology and Zoology 50 3 331 - 339 2015年08月 [査読有り]
     
    In the last 30 years some limited successes in alien ant control have been documented globally, and control programs remain challenging. Moreover, the potential non-target impacts of toxicants have not been well studied. We assessed the efficacy and non-target effects of multiple products containing the active compound fipronil in the attempted control of two populations of the invasive Argentine ant Linepithema humile (Mayr) in Tokyo, Japan. Three treatments were conducted: control, low-dose treatment (0.1 g/ha per treatment), and high-dose treatment (0.2 g/ha). Treatments were applied once per month for 11 months. The abundance of L. humile declined rapidly by up to 99.8 % in treated areas, but remained at extremely high densities in the control area. The treatments had few negative non-target effects, with the abundances of native ant species and other ground-dwelling invertebrates except for cockroaches being greater in the treated areas after L. humile suppression. Thus, fipronil is an effective compound for controlling L. humile and can be used with minimal toxic effects on non-target organisms. The treatments cost approximately US$ 575/ha for the low-dose treatment and US$ 1250/ha for the high-dose treatment. Our research supports the creation of more ambitious invasive ant management projects.
  • Ishida T; Sawahata T; Kanaya G; Hayasaka D
    Crustaceana 88 5 511 - 521 2015年 [査読有り]
     
    As part of a clarification of the response mechanisms of beach ground arthropods to the 2011 Tohoku-oki tsunami, a pit-fall trap survey was conducted in August and September 2012 and 2013 on four relatively flat sandy beaches in northern Tohoku region (i.e., northern Iwate to southern Aomori Prefecture) in Japan. At each beach surveyed, eight clean plastic cups with no baits were put for two days on each of the five beach zones (i.e., wrack, non-vegetated, short-herbaceous, tallgrass, and shrub zones). Among the ground arthropods in this study, we report the differences in susceptibility of two sandhoppers (Trinorchestia trinitatis and T. longiramus), which dominate on the beaches and play an important role as prey for beach predators, to the tsunami, through monitoring their population dynamics. Although the abundance of the two species increased with time after the disturbance, T. trinitatis had a higher population growth rate than T. longiramus. In 2012, these two talitrid amphipods were collected mostly in the wrack zone, where the seaweed and driftwood accumulated, and on the non-vegetated zone near the shoreline, whereas they occurred in all beach zones in 2013. Since T. trinitatis burrows near the beach surface during its reproductive period in spring, this species might have suffered a large impact from the tsunami's coastal erosion. On the other hand, our findings suggest that Trinorchestia species rapidly recolonize coastal regions in a short period of time (within a year), due to their reproductive ability and the accumulation of sea wrack, which provides food and habitat to these sandhoppers.
  • 岩手県の砂浜植生回復に関わる生態学的な評価と保全対策の提案.
    島田直明; 川西基博; 早坂大亮
    総合政策 16 1 19 - 34 2014年09月 [査読有り]
  • 早坂 大亮
    日本農薬学会誌 39 2 108 - 114 Pesticide Science Society of Japan 2014年08月 [査読有り][招待有り]
  • The relation between road crack vegetation and plant biodiversity in urban landscape
    Uchida T; Xue JH; Hayasaka D; Arase T; Haller WT; Gettys LA
    International Journal of GEOMATE 6 2 885 - 891 2014年06月 [査読有り]
  • Hayasaka D
    Journal of Pesticide Science 39 3-4 172 - 173 2014年 [招待有り]
     
    Our knowledge of the ecological impact of insecticides on aquatic organisms is lacking at a community level because it requires high research skills, due to the complexity of community interactions. Here, the aquatic community's response to the residues of two systemic insecticides, imidadoprid and fipronil, with different physicochemical properties was monitored for three years. In this study, four key points are considered for evaluating the ecological impact of the insecticides in relation to biodiversity conservation. These are as follows: (1) environmental fates as explained by their different physicochemical properties, (2) life cycles and habitats of each taxonomic and functional group, (3) indirect effects through the food chain, and (4) long-term field monitoring over the course of a year. (C) Pesticide Science Society of Japan
  • 與猶久恵; 内田泰三; 荒瀬輝夫; 早坂大亮
    日本緑化工学会 39 1 50 - 55 JAPANESE SOCIETY OF REVEGETATION TECHNOLOGY 2013年09月 [査読有り]
     
    本研究では，絶滅危惧種コギシギシの保護あるいは保全に資する基礎的知見を得ることを目的とした。ここでは，コギシギシ痩果の外部形態ならびに発芽特性について検討を行った。後者においては，高-低温湿層処理ならびに乾燥暗所処理が発芽に及ぼす影響から考察した。その結果，コギシギシの痩果は，3 枚の花被片からなり，それぞれの縁に長い刺を有する点に特徴づけられ，エゾノギシギシの痩果に近い形態にあると考えられた。しかし，それぞれの花被片に粒体が付属する点はエゾノギシギシと異なった。一方，高-低温湿層処理ならびに乾燥暗所処理が発芽に及ぼす影響は認められず，痩果の生理的休眠は浅いものと推察された。
  • 早坂大亮; 鈴木一隆; 是永知子; 諸岡(斎藤; 歩希; 野村拓志; 深澤圭太; Sánchez-Bayo F; 五箇公一
    日本農薬学会誌 38 2 101 - 107 Pesticide Science Society of Japan 2013年08月 [査読有り]
     
    The effects of two successive annual treatments of imidacloprid and fipronil on dragonfly nymph communities, which are one of the best-known bioindicators in Japanese agroecosystems, were monitored in experimental paddies. The abundance of dragonfly nymphs was lower in both insecticides-treated fields than it was in the controls, particularly following fipronil treatments. Residues of both insecticides were found in the soil throughout the two years, and imidacloprid persisted in water up to three months following each treatment. A Principal Response Curve analysis (PRC) showed that the second annual treatments caused greater structural changes in dragonfly nymph communities than the initial treatments caused, particularly for fipronil. The community structures continued to change even after the insecticides dissipated from the water. This suggests that ecological impacts, and therefore risks, of imidacloprid and fipronil on dragonfly nymph communities depend more on soil residues than they do on waterborne residues. As expected, susceptibility of dragonfly nymphs to these two insecticides differed among species.
  • 早坂大亮; 永井孝志; 五箇公一
    日本生態学会誌 63 2 193 - 206 日本生態学会暫定事務局 2013年07月 [査読有り]
     
    農薬は作物の品質・収量確保の上で必要不可欠である一方、持続的な農業活動に向けては生物多様性を無視することはできない。本稿では、今後の農薬の生態リスク管理手法として取り入れるべき、多種系あるいは群集レベルの評価手法について概説するとともに、これら手法の有効性・可能性と今後の展望について議論する。日本における現行の農薬管理は、農薬の曝露影響と生物への影響の濃度とを対比させて評価を行う。農薬の曝露影響は多段階の評価制度(Tier制)が確立されているが、生物影響は個体レベルの室内毒性試験のみで評価されており、群集(生態系)レベルでの評価手法は確立されていない。また、室内試験の結果を野外環境に外挿することの難しさは多くの研究者により指摘されている。近年、個体レベルの評価から多種系の評価に外挿する手法として、農薬に対する各生物の感受性差を考慮した統計学的手法である種の感受性分布(SSD:Species Sensitivity Distribution)が開発されている。これにより、生物集団の潜在影響を簡便に評価できる一方で、生物間相互作用や群集の回復性などは考慮できない。これら課題の解決に向けて、メソコスムを含む実験生態系による試験の実施が有効であると考える。実験生態系は、多種の生物に対する影響を同時に試験可能であるとともに、コントロール(対象区)を設定できる、などの利点がある。群集レベルの農薬の生態リスク評価にはこれまで、多様度指数や主成分分析等が指標として用いられてきたが、何れも生物多様性への影響評価として解釈が困難であった。そこで、コントロールと農薬処理区との群集組成の時間変化における差に着目した多変量解析である主要反応曲線(PRC:Principal Response Curves)解析が開発され、現在、多くの現場で使用されている。一方、曝露後影響のモニタリング期間が短い場合、世代期間(生活史サイクル)の長い生物に対する影響を過小評価してしまう危険性がある。1年以上の長期モニタリングを行うことで、各種の生活史も考慮したより現実的な生態リスクの評価が可能になる。これらの課題を踏まえ、今後の生物影響の評価システムとして、室内毒性試験、種の感受性分布、および実験生態系による長期モニタリングを一つの評価パッケージとして段階的に実施することを我々は提案する。その上で、これら試験結果から総合的に導かれる農薬の毒性について曝露影響と比較することで、農薬の生態リスクの総合評価による登録保留基準の設定が可能になると考える。
  • 五箇公一; 早坂大亮
    環境毒性学会誌 16 2 21 - 28 日本環境毒性学会 2013年07月 [査読有り]
     
    The ecological risk assessment has become incleaseingly an important issue of the conservation of biodiversity. Many countries including Japan have introduced the test guideline maintained by OECD, in which the ecological risk of each chemicals is assessed based on the acute toxicity test of the three water organism species, that is algae, water flea, and fish, in the laboratory. However, there is little in the studies regarding whether such toxicity data reflect the ecological impacts of each chemical in the actual field. We have promoted the paddy field masocosm test for assessing how insecticides influence the communities of organisms in paddy fields, which is difficult to predict by laboratory tests. We tested the ecological impacts caused by the 2 systemic insecticides, imidacroprid and fipronyl, widely used in the Japanese paddy fields by the paddy field masocosms sice 2010 to 2012. In each the year, we conventionarily applied the chemical into the experimental paddy fields and researched the occurrence of water organism species. As result, we could detect that the insecticides severely influenced the population dynamics of some species even under the standard concentration for the environmental safety provided by the OECD test guideline. And also it was discovered that the divergence of community components of the insecticide applied paddy fields from those of non-chemical paddy filelds increased as years go by because of accumulation of the insecticides residues. We aim to construct and spread a standard method for mesocosm test to each region in Japan for assessing the ecological impact of pesticide to each regional ecosystem.
  • Hayasaka D; Suzuki K; Nomura T; Nishiyama M; Nagai T; Sanchez-Bayo F; Goka K
    Journal of Pesticide Science 38 1-2 44 - 47 2013年 [査読有り]
     
    The acute toxicity (48-hr) of old (imidacloprid) and new (clothianidin) neonicotinoid insecticides to five cladoceran species and species sensitivity distribution (SSD) for cladocerans and other aquatic organisms to these insecticides are compared here. The sensitivities to both insecticides were in the following descending order: Ceriodaphnia>Daphnia>Moina. Differences in the 5% hazardous concentration (HC5) threshold between the two species taxa to each compound indicated that clothianidin was 4 times less toxic than imidacloprid only to cladocerans. (C) Pesticide Science Society of Japan
  • Record of Nabis (Nabis) ferus (LINNAEUS, 1758) (Heteroptera: Nabidae) in Osuka Beach, Aomori, Japan
    Nomura T; Hayasaka D
    Rostria 55 33 - 36 2013年 [査読有り]
  • Hayasaka D; Shimada N; Konno H; Sudayama H; Kawanishi M; Uchida T; Goka K
    Ecological Engineering 44 227 - 232 2012年07月 [査読有り]
     
    The infrequency of tsunamis results in a lack of knowledge regarding the impact they have on ecosystems. Comparison of the floristic composition before and after tsunamis using permanent plots is an effective approach to estimate the ecological impacts of tsunamis in coastal environments. Here, we report the floristic changes in beach vegetation in northern Tohoku, Japan caused by the 2011 Tohoku-oki tsunami. Among the beaches studied, we observed differences in the vegetative characteristics of the beach flora, whereas similarities were found in vegetation response patterns, particularly for herbaceous vegetation. No significant interaction was found between the overall number of vascular plant species or the number of non-beach species and the tsunami disturbance; conversely, on beaches that experienced relatively small impacts, the number of typical/characteristic beach species, Pielou evenness index values, and Shannon-Wiener diversity index values were significantly lower after the tsunami. Following the tsunami, the herbaceous vegetation species composition on all of the beaches was characterized by a few non-beach species that are known to tolerate strong anthropogenic disturbances; in contrast, the damage to shrub vegetation was lower than that to herbaceous vegetation. Our findings are similar to what was observed following the 2004 Indian Ocean tsunami in Thailand, suggesting that the initial response patterns of beach vegetation to tsunamis are similar, regardless of the affected climatic zone and species composition. Long-term field monitoring is needed to elucidate post-tsunami recovery, vegetation succession, and the ecological impact of the increase of non-beach species. (C) 2012 Elsevier B.V. All rights reserved.
  • Hayasaka D; Goka K; Thawatchai W; Fujiwara K
    Biodiversity and Conservation 21 8 1971 - 1985 2012年07月 [査読有り]
     
    Our knowledge of how coastal species react to, and recover from, tsunamis is deficient because of the infrequency of these events, despite the importance of such information for ecological risk assessment of coastal hazards. To elucidate the differences in resilience among species and the successional processes of coastal sand-dune flora after tsunamis, we monitored the ecological impacts of the 2004 Indian Ocean tsunami on coastal sand-dune species on Phuket Island, Thailand. Using 127 floristic inventory datasets, we compared the occurrence, species composition, characteristics, and eco-morphological adaptations of coastal sand-dune species before and after the tsunami. Among the 73 species recognized, the occurrences of 28 changed significantly after the tsunami. The impacts on coastal sand-dune species of non-coastal sand-dune species invading the dunes after the disaster were temporary and minimal, perhaps because of constant coastal stresses such as sand movement and salt spray. Damage to woody species was less than that to herbaceous species. There were clear post-tsunami differences in the successional trajectories of coastal sand-dune flora (particularly herbaceous vegetation) between protected beaches with low-level anthropogenic disturbance and resort beaches. The tsunami-related qualitative variations on each beach were clearly explained not by changes in the Shannon-Wiener diversity index but by differences in species number (i.e., species richness). Numbers of coastal sand-dune species (particularly monophytes and those growing clonally by stolons) decreased significantly on protected beaches after the tsunami. We suggest that the recovery process-including its direction, trajectory, and duration-in coastal sand-dune species after tsunamis depends strongly on the individual beach structure and the degree of anthropogenic disturbance, including trampling pressure and beach development. Evaluation of species in terms of functional traits is effective for assessing sand-dune status after tsunamis.
  • Hayasaka D; Korenaga T; Suzuki K; Saito F; Sanchez-Bayo F; Goka K
    Ecotoxicology and Environmental Safety 80 355 - 362 2012年06月 [査読有り]
     
    Agricultural landscapes, including paddies, play an important role in maintaining biodiversity, but this biodiversity has been under the threat of toxic agro-chemicals. Our knowledge about how aquatic communities react to, and recover from, pesticides, particularly in relation to their residues, is deficient, despite the importance of such information for realistic environmental impact assessment of pesticides. The cumulative ecological impacts on aquatic paddy communities and their recovery processes after two successive annual applications of two systemic insecticides, imidacloprid and fipronil, were monitored between mid-May and mid-September each year. The abundance of benthic organisms during both years was significantly lower in both insecticide-treated fields than in the controls. Large-impacts of fipronil on aquatic arthropods were found after the two years. Growth of medaka fish, both adults and their juveniles, was affected by the application of the two insecticides. A Principal Response Curve analysis (PRC) showed the escalation and prolongation of changes in aquatic community composition by the successive annual treatments of each insecticide over two years. Residues of fipronil in soil, which are more persistent than those of imidacloprid, had a high level of impact on aquatic communities over time. For some taxonomic groups, particularly for water surface-dwelling and water-borne arthropods, the second annual treatment had far greater impacts than the initial treatment, indicating that impacts of these insecticides under normal use patterns cannot be accurately assessed during short-term monitoring studies, i.e., lasting less than one year. It is concluded that realistic prediction and assessment of pesticide effects at the community level should also include the long-term ecological risks of their residues whenever these persist in paddies over a year. (C) 2012 Elsevier Inc.. All rights reserved.
  • Hayasaka D; Kimura N; Fujiwara K; Thawatchai W; Nakamura T
    Journal of Tropical Forest Science 24 2 265 - 274 2012年04月 [査読有り]
     
    HAYASAKA D, KIMURA N, FUJIWARA K, THAWATCHAI W & NAKAMURA T. 2012. Relationship between microenvironment of mangrove forests and epiphytic fern species richness along the Pan Yi River, Thailand. To clarify the habitat dependency of epiphytic ferns in mangrove forests, we surveyed their species composition and habitat requirements along the Pan Yi River, Thailand. In a multiple regression analysis, the Shannon Wiener diversity index of epiphytic ferns was most strongly related to the diversity index (H') of mangrove trees. Cynometra iripa, Heritiera littoralis and Xylocarpus moluccensis were utilised as host trees by almost all epiphytic ferns. The occurrence of Nephrolepis acutifolia has a positive association with Xylocarpus moluccensis trees by a chi-square goodness-of-fit test. At the family level, Polypodiaceae and Davalliaceae were most prominent in mangroves of the Pan Yi river basin. Based on canonical correspondence analysis (CCA), the factors associated with the occurrence of epiphytic ferns were distance from the edge of the river (p < 0.05), water salinity (p < 0.05), relative light intensity (RLI) (p < 0.05) and diameter at breast height (dbh) (p < 0.05). Our results showed that Drynaria quercifolia, Davallia denticulata, N. acutifolia and Pyrrosia lanceolata were dominant species in the mangrove environment, although each of them had a different habitat. Nephrolepis acutifolia and Davallia solida are epiphytic ferns occurring almost exclusively in mangroves.
  • Hayasaka D; Korenaga T; Suzuki K; Sanchez-Bayo F; Goka K
    Ecotoxicology 21 2 421 - 427 2012年03月 [査読有り]
     
    Differences in susceptibility of five cladocerans to the neonicotinoid imidacloprid and the phenyl-pyrazole fipronil, which have been dominantly used in rice fields of Japan in recent years, were examined based on short-term (48-h), semi-static acute immobilization exposure tests. Additionally, we compared the species sensitivity distribution (SSD) patterns of both insecticides between two sets of species: the five tested cladocerans and all other aquatic organisms tested so far, using data from the ECOTOX database of U.S. Environmental Protection Agency (USEPA). The sensitivity of the test species to either imidacloprid or fipronil was consistent, spanning similar orders of magnitude (100 times). At the genus level, sensitivities to both insecticides were in the following descending order: Ceriodaphnia > Moina > Daphnia. A positive relationship was found between body lengths of each species and the acute toxicity (EC50) of the insecticides, in particular fipronil. Differences in SSD patterns of imidacloprid were found between the species groups compared, indicating that test cladocerans are much less susceptible than other aquatic species including amphibians, crustaceans, fish, insects, mollusks and worms. However, the SSD patterns for fipronil indicate no difference in sensitivity between cladocerans tested and other aquatic organisms despite the greater exposure, which overestimates the results, of our semi-static tests. From these results, Ceriodaphnia sp. should be considered as more sensitive bioindicators (instead of the standard Daphnia magna) for ecotoxicological assessments of aquatic ecosystems. In addition, we propose that ecotoxicity data associated with differences in susceptibility among species should be investigated whenever pesticides have different physicochemical properties and mode of action.
  • Hayasaka D; Korenaga T; Sanchez-Bayo F; Goka K
    Ecotoxicology 21 1 191 - 201 2012年01月 [査読有り]
     
    The environmental risks of pesticides are typically determined by laboratory single-species tests based on OECD test guidelines, even if biodiversity should also be taken into consideration. To evaluate how realistic these assessments are, ecological changes caused by the systemic insecticides imidacloprid and fipronil, which have different physicochemical properties, when applied at recommended commercial rates on rice fields were monitored using experimental paddy mesocosms. A total of 178 species were observed. There were no significant differences in abundance of crop arthropods among the experimental paddies. However, zooplankton, benthic and neuston communities in imidacloprid-treated field had significantly less abundance of species than control and fipronil fields. Significant differences in abundance of nekton community were also found between both insecticide-treated paddies and control. Influences on the growth of medaka fish were also found in both adults and their fries. Both Principal Response Curve analysis (PRC) and Detrended Correspondence Analysis (DCA) showed the time series variations in community structure among treatments, in particular for imidacloprid during the middle stage of the experimental period. These results show the ecological effect-concentrations (LOEC similar to 1 mu g/l) of these insecticides in mesocosms, especially imidacloprid, are clearly different from their laboratory tests. We suggest that differences in the duration of the recovery process among groups of species are due to different physicochemical properties of the insecticides. Therefore, realistic prediction and assessment of pesticide effects at the community level should consider not only the sensitivity traits and interaction among species but also the differences in physicochemical characteristics of each pesticide.
  • Hayasaka D; Akasaka M; Miyauchi D; Box EO; Uchida T
    Flora 207 2 126 - 132 2012年 [査読有り]
     
    Information on mechanisms of differentiation or homogenization of urban floras is deficient, despite their importance for urban nature conservation and urban land management. Roads, as a major human promoter of urbanization, can be an initial habitat for plants dispersed by transportations. We assumed that variation in weed vegetation along urban-rural roadside gradients is small, particularly in curbside cracks. We classified vegetation occurring in curbside cracks along the National Route 3 in southern japan and compared the characteristics of the vegetation types recognized. Species in curbside cracks were recorded on 40 plots. Three vegetation types were classified, in part related to surrounding land-use types. Although the Shannon-Wiener diversity index and the number of native species clearly differed among the vegetation types in the curbside cracks, no significant differences between the three floristic vegetation types were found in the number of non-natives and invasive alien species. This may result from the small specificity and complexity of landscape structures, due to the continuity and connectivity of paved-road networks. Of the 122 species, 44 were non-natives or invasive alien species. The vegetation types generally involved the same plant families, with large numbers of species from the Asteraceae and Poaceae, regardless of vegetation types, but frequency of occurrence of the two families clearly differed between natives and non-natives and invasive alien species. Ephemeral non-natives and invasive alien species. particularly Asteraceae and Poaceae, seem to have advantageous dispersal strategies or low habitat dependency facilitating their occurrence in curbside cracks, regardless of adjacent land uses and the urban-rural landscape gradient. Expansion of these species may cause a homogenization of regional floras along roads. (C) 2011 Elsevier GmbH. All rights reserved.
  • コラム 緑化植物 ど・こ・ま・で・き・わ・め・る “イワダレソウ類 [イワダレソウ: Lippia nodiflora (L.) Michx.とヒメイワダレソウ: Lippia canescens Kunth]”.
    早坂 大亮
    日本緑化工学会誌 38 2 308  2012年
  • Hayasaka D; Akasaka M; Miyauchi D; Uchida T
    Weed Technology 25 3 411 - 421 2011年07月 [査読有り]
     
    Growth of vegetation in curbside cracks causes deterioration of asphalt and curbs, reducing road longevity and safety capabilities. Road managers spend a considerable amount of time and money on roadside vegetation management every year. The vegetation in curbside cracks in these study regions is managed approximately once a year by mowing and road sweeping using street-sweeper trucks. Nevertheless, ideal management practices of roadside vegetation have not yet been established partly due to insufficient knowledge of the ecological strategies of plants invading roadsides, especially curbside cracks. Although establishment of plants in the cracks might be restricted due to severe anthropogenic road disturbances, the cracks could be habitats for species with specific ecological traits. The objective of this study was to clarify the floristic and functional characteristics of roadside weeds, particularly species invading curbside cracks, to provide information for effective road management. The species composition of plants invading the cracks was surveyed along Route 3 (southern Japan) and Route 4 (eastern Japan) in different climatic zones, based on 108 floristic inventories. We compared species occurrence and composition to characterize the dominant ecomorphological traits of the species. In total, 163 species occurred in curbside cracks along both routes. Species composition of vegetation in curbside cracks was more variable between the routes than between land-use types. Of the 54 species, more than 5% occurred in all plots, and only three had differences in occurrence among land-use types. Ecomorphological trait composition patterns of the species were similar across land-use types. From these results, we found that regardless of differences in species composition among regions, climatic conditions, and surrounding land-use type, there were some dominant ecomorphological traits of roadside vegetation with plants in curbside cracks, such as ephemeral monophytes that are barochorous or anemochorous. By contrast, rhizomatous perennials, which cause greater deterioration of asphalt than ephemeral monophytes, were rare along the cracks. Although vegetation composition and structure generally depend on land-use types and disturbance regimes, linear landscape elements such as curbsides might be habitats for plants adapted to road disturbances. Roadside vegetation management, such as mowing and road sweeping once a year, seems sufficient to restrict establishment of rhizomatous perennials around Japan.
  • Hayasaka D; Fujiwara K; Box EO
    Applied Vegetation Science 12 2 211 - 224 2009年04月 [査読有り]
     
    Question: How rapidly has the sandy beach and maritime forest vegetation on Phuket recovered and regenerated after the impact of the major Indian Ocean tsunami of 2004? What are the characteristics of sandy beach species for regenerating their populations and the invasion patterns of originally non-sandy beach species or other newcomers after the tsunami? Location: Phuket Island, southern Thailand. Methods: Species composition of beaches was studied on the same research plots 6 months before and 9 months after the tsunami. The changes in individual species cover before and after the tsunami were determined by chi(2) tests. Change in community composition was analysed by detrended correspondence analysis. The relationship between species and environmental factors was analysed by canonical correspondence analysis. Results: The sites disturbed by the tsunami were often invaded by annuals, especially grasses and asteraceous plants, rather than by perennials. In contrast, species with clonal growth by stolons decreased significantly. Factors determining the species habitat differences were soil hardness (penetration resistance of sandy soil), per cent silt content, soil water content and beach management. Habitat differences among originally non-sandy beach herbaceous species that expanded their population or moved to the coast after the disaster were defined by sand accretion or erosion caused by the tsunami. Many sandy beach herbaceous communities changed into Dactyloctenium aegyptium communities because of the tsunami were originally constituted by non-sandy beach D. aegyptium with Cenchrus echinatus. Although the forest floors of most maritime forests were invaded by originally non-sandy beach Tridax procumbens, Eleusine indica or D. aegyptium because of the tsunami, this did not result in a change in the vegetation unit, because species' loss was restricted to the understorey. In time, these forests will recover their previous community composition. Conclusions: Our results suggest that originally non-sandy beach native species invaded the disturbed beaches rapidly after the tsunami but their habitats differ. Sites where sand accumulated on a beach because of the tsunami were invaded by D. aegyptium and E. indica, whereas soil erosion permitted invasion by Digitania adscendens. Tridax procumbens establishes rapidly on wet sites with hard soil, high per cent silt content and low beach management pressure. Sandy beach species with subterranean long rhizomes are strongly tolerant of such disasters. We concluded that the species composition of the beaches disturbed by a temporary large disaster is determined by dormancy and growth forms, with radicoid form being influential.
  • 早坂大亮; 柾木淳子; 前田宣雄; 江頭信一
    こうえいフォーラム 17 17 97 - 102 日本工営技術委員会 2009年02月 [査読有り]
  • Habitat differences and spatial distribution patterns of maritime strand forest and adjacent inland forest on subtropical Iriomote island, southern Japan
    Hayasaka D; Fujiwara K
    Ecotropica 13 2 121 - 134 2007年 [査読有り]
  • 早坂大亮; 藤原一繪
    日本緑化工学会誌 32 2 346 - 354 日本緑化工学会 2006年11月 [査読有り]
     
    今後の海岸管理・海浜植物群落保全に対する基礎資料を作成する事を目的とし,人為的活動,開発圧の強い湘南海岸に現存する植物群落(海浜・非海浜植物群落を含む)の成立に及ぼす影響について検討した。現地植生調査資料を相互に比較,整理した結果,現在,湘南海岸には,4クラス,9群集,6群落(上級単位不明の2群落を含む)が成立していた。土壌窒素含量,土質,1m^2あたりの平均海水浴客数および清掃頻度を用いて主成分分析を行った結果,オカヒジキクラス,ハマボウフウクラスよびハマゴウクラスは,人為的影響が弱い貧栄養地に,オオバコクラスおよび上級単位不明の群落は,細礫率が高く土壌窒素分の高い立地に成立傾向にあり,クラス間で明確な立地環境の違いが認められた。非海浜植物群落であるギョウギシバ群落およびコマツヨイグサ群落は湘南海岸全域で広く見られたが,コマツヨイグサ群落は攪乱強度の低い海岸前面の裸地に,ギョウギシバ群落は人為的攪乱により形成された裸地に侵入するというように,定着場所に明確な違いが認められた。これら群落の分布拡大は神奈川県内だけにとどまらず,人為的影響の強い様々な海岸で生じている。人間の利用地域と海浜植物群落の保護地域との明確な境界を引き,内陸生雑草の侵入経路である植被の隙間(植生の面的拡がりが,人為的攪乱によってパッチ状になること)を作らない事が有効であると考えられる。湘南海岸で見られる全植生単位が,平塚市および大磯町で網羅される事から,今後は,これら2市町を要保全地域として管理していく必要がある。
  • Hayasaka D; Fujiwara K
    Tropics 14 3 245 - 254 2005年03月 [査読有り]

書籍

  • Physio-ecological activity of Phragmites japonica as a green infrastructure plant
    Uchida T; Arase T; Sato Y; Hayasaka D (担当:共著範囲:)The GEOMATE International Society 2018年11月 ISBN: 9784909106001
  • Dynamics of exotic grass cover plants on slopes.
    Uchida T; Tanaka J; Kondo K; Hayasaka D; Tomoguchi Y; Arase T; Okano T (担当:分担執筆範囲:In Hossain Z, Horpibulsuk S (eds). Geotechnique, Construction Material and Environment.)The GEOMATE International Society 2016年12月 686 532-537
  • Susceptibility of sandy beach flora to the Great East Japan Earthquake and Tsunami in nothern Tohoku, Japan
    Hayasaka D; Yamada K; Uchida T (担当:分担執筆範囲:in Urabe J, Nakashizuka T (eds). Ecological impacts of tsunamis on coastal ecosystems: lessons from the Great East Japan Earthquake)Springer 2016年11月 ISBN: 9784431564461 410 271-288
  • 海岸砂丘植生に及ぼす津波のインパクト
    日本生態学会東北地区会編 (担当:共著範囲:生態学から見た東日本大震災 -自然が語る震災の意味-．pp98-104)文一総合出版．東京 2016年03月
  • The species composition of buried seeds of seashore vegetation disturbed by the Great East Japan Earthquake and Tsunami in nothern Tohoku, Japan
    Kawanishi M; Hayasaka D; Shimada N (担当:分担執筆範囲:in Urabe J, Nakashizuka T (eds). Ecological impacts of tsunamis on coastal ecosystems: lessons from the Great East Japan Earthquake)Springer 2016年 410 289-309
  • Succession of exotic grasses used as cover plants for erosion control on cut slopes, Mt. Sakurajima. Hossain Z, Kaneko S (eds.), Science Engineering & Environment, pp.501-506
    Kondo K; Uchida T; Hayasaka D; Tanaka J; Sato A; Arase T (担当:共著範囲:)The GEOMATE International Society, Mie, Japan, 649pp. (ISBN: 978-4-9905958-5-2 C3051) 2015年09月
  • Role of a retaining wall constructed of natural stones in plant biodiversity. In Hossain Z, Hossain S (eds.) Geotechnique, Conservation Materials & Environment vol.4, pp.432-437.
    Uchida T; Furuno M; Minami T; Yamashita S; Uchiyama T; Arase T; Hayasaka D (担当:共著範囲:)The GEOMATE International Society, Japan, 590pp. (ISBN:978-4-9905958-3-8 C3051) 2014年09月
  • Role of curbside crack of road in urban biodiversity. Hossain Z, Hossain S (eds.), Geotechnique, Construction Materials & Environment vol.3, pp.427-432
    Uchida T; Huan XJ; Hayasaka D; Arase T; Haller WT; Gettys LA (担当:共著範囲:)The GEOMATE International Society, Mie, Japan. 733pp. (ISBN: 978-4-9905-9580-1 C3051) 2013年
  • Roll of curbside crack of road in urban biodiversity. In Geotechnique, Construction Material & Environment
    Uchida T; Huan XJ; Hayasaka D; Arase T; Haller WT; Gettys LA (担当:共著範囲:)The GEOMATE International Society, Mie, Japan 2013年

MISC

受賞

  • 2022年12月 日本生態学会近畿地区会 2022年度日本生態学会近畿地区会委員会・総会・例会 奨励賞
     温暖化が競争的置換を駆動する？-北上する侵入種が在来トンボに与える影響- 
    受賞者: 長野光希;平岩将良;石若直人;瀬古祐吾;橋本洸哉;早坂大亮
  • 2022年09月 日本陸水学会 日本陸水学会第86回兵庫大会 優秀口頭発表賞（未来開拓枠）
     農薬と水温上昇が水田生物群集に与える複合的な影響と捕食－被食を介した間接効果の可能性 
    受賞者: 石若 直人;橋本洸哉;平岩将良;角谷拓;早坂大亮
  • 2021年03月 日本生態学会 ポスター賞優秀賞（動物個体群）
     ハプロタイプごとに異なるアルゼンチンアリの採餌行動 
    受賞者: 瀬古祐吾;一山智也;早坂大亮;澤畠拓夫
  • 2020年11月 Greem Infrastructure Network Japan 優秀賞（学生・若手研究者部門）
     都市における小規模グリーンインフラの役割―街路樹の生物多様性機能― 
    受賞者: 古野正章;内田泰三;薛竣桓;早坂大亮;荒瀬輝夫
  • 2020年09月 日本緑化工学会 第51回日本緑化工学会大会 優秀ペーパー賞（技術報告部門）
     河川水辺の国勢調査結果を用いた九州の一級水系における河川環境，とくに外来植物群落の変遷に関する考察 
    受賞者: 友口勇生;内田泰三;早坂大亮
  • 2017年09月 ELR ELR2017名古屋大会 ポスター優秀賞（緑化、植物-植生系部門）
     「切土法面に繁茂するクズに対する植生管理が在来植物と土壌環境改変者に及ぼす作用」 
    受賞者: 早坂 大亮
  • 2014年11月 GEOMATE International Society Best Paper Award of the GEOMATE International Society
     "Role of a retaining wall constructed of natural stones in plant biodiversity" 
    受賞者: Taizo UCHIDA;Masaaki FURUNO;Takashi MINAMI;Sampei YAMASHITA;Tadashi UCHIYAMA;Teruo ARASE;Daisuke HAYASAKA
  • 2014年03月 公益財団法人 食品農医薬品安全性評価センター 望月喜多司記念 奨励賞
     
    受賞者: 早坂 大亮
  • 2014年03月 日本農薬学会 平成26年度 日本農薬学会奨励賞
     「水田メソコスムにおける生物群集に及ぼす殺虫剤の影響に関する研究」 
    受賞者: 早坂 大亮
  • 2012年10月 植生学会 植生学会第17会大会 口頭発表賞
     「2011東北沖津波による海岸砂丘植生への生態影響評価」 
    受賞者: 早坂 大亮
  • 2012年09月 ELR ELR2012東京大会 ポスター最優秀賞（環境評価・計画系部門）
     「育苗箱施用殺虫剤の連続施用が水田生物群集におよぼす影響」 
    受賞者: 早坂 大亮
  • 2011年03月 日本生態学会 第58回日本生態学会大会 ポスター優秀賞（種多様性・菌類・微生物部門）
     「物理化学性状の異なる農薬が水田生態系に及ぼす影響 -水田メソコスム試験事例」 
    受賞者: 早坂 大亮

共同研究・競争的資金等の研究課題

  • 奈良県：受託研究
    研究期間 : 2023年05月 -2024年03月 
    代表者 : 【代表者】澤畠 拓夫; 【分担者】早坂 大亮
  • 日本学術振興会：科学研究費助成事業 挑戦的研究(開拓)
    研究期間 : 2021年07月 -2024年03月 
    代表者 : 早坂 大亮; 【分担者】角谷 拓(国立環境研)
     
    本研究は、農薬の曝露拠点であり、かつ生物・生態系サービスのホットスポットである水田をモデルに、複合影響要因や地理的影響を操作・比較可能な野外・開放系実験を主軸として、①汎用的な生態系把握のためのコア機能群（共通の特性をもつ生物種や個体群の集合）や相互作用の特定と、②実用的な生態系機能の指標（生態系レジリエンス指標）の検討に取り組み、もって化学物質による群集・生態系への実効性のある影響評価手法を検討するものである。 令和3年度は全国的なコロナ禍の猛威により、現地調査や出張自体がままならず、思うような進捗は達成できなかったが、各サブテーマで以下のような成果が得られた。 サブテーマ①の成果：加温と農薬曝露に対する生物群集の組成についてモニタリングした結果、農薬曝露単独処理区の群集組成は時間経過とともに無処理区と近似する傾向にある一方、複合処理の群集組成は常に無処理区と異なる傾向にあった。一方で、加温単独処理の組成は、時間経過とともに無処理と乖離した。つまり、複合処理では、農薬の影響と加温の影響が入れ替わるように群集に作用したことで、生態影響が長期化した可能性が示唆された。また、各生物群の密度に着目すると、農薬処理による捕食性昆虫の密度低下にともない餌生物種の密度が増加するといった、生物間相互作用を介した間接効果を示唆する結果も得られた。 サブテーマ②の成果：野外操作実験区における生物の個体数モニタリングデータにもとづいて、多数の生物間で構成される相互作用ネットワークの定量化を試みた。その上で、ネットワークの中心性や連結性などのトポロジー構造や、相互作用強度や強度の時間変動などの定量的な性質など、実験処理として与える人為かく乱に対する生物群集の応答に影響を及ぼすことが想定される生物間相互作用ネットワークの特性値を算出・定量化した。
  • 奈良市に侵入した特定外来生物アルゼンチンアリの分布境界の実態把握調査業務
    奈良県：受託研究
    研究期間 : 2022年10月 -2023年03月 
    代表者 : 早坂 大亮, 【分担者】澤畠拓夫(近畿大)
  • 屋久島環境文化財団：屋久島生物多様性保全研究活動奨励事業
    研究期間 : 2021年04月 -2023年03月 
    代表者 : 早坂大亮
  • 日本学術振興会：科学研究費助成事業 基盤研究(B)
    研究期間 : 2019年04月 -2023年03月 
    代表者 : 早坂 大亮; 【分担者】川西 基博(鹿児島大); 奈良 一秀(東京大); 澤畠 拓夫(近畿大); 橋本 洸哉(国立環境研)
     
    本研究は、2015年に鹿児島県口永良部島で発生した噴火直後の特異な現象、すなわち一次遷移の一般的な先駆植物に先立ってクロマツを主体とした「樹木」が広域に侵入したメカニズムを解明するにあたり、地上部－地下部の関係性から議論することを目指すものである。 研究2年目は、前年度に引き続き、撹乱跡地における植生（植物種子を含む）、菌根菌および種子・菌根菌散布者等の調査を実施した。なお、コロナ禍で当初計画を達成したとは言い難い。各項目の成果は以下の通りである。 1）植生（植物種子を含む）調査および地形測量： 森林域において、森林を対象として植生調査と埋土種子調査を行った。照葉樹二次林、スギ植林、火砕流跡地の各林分間で、植物の種組成と種多様性を比較した。結果、火砕流攪乱後の植生回復過程では、シカの不嗜好種である低木とシダ植物の優占度が著しく大きいことが明らかになった。同様の傾向は埋土種子集団でもみられ、火砕流による攪乱が種多様性、特に均等度の低下を引き起こしている可能性が示唆された． 2）菌根菌調査： 火山泥流跡地に生育する1-4年生クロマツの外生菌根菌群集を調査した。その結果、マツ科樹木に特異性の高いショウロ属・ヌメリイグチ属やアテリア科が高頻度で検出された。 3）種子・菌根菌散布者（主に節足動物）調査： 引き続き、火砕流跡地およびその周辺で土壌動物調査を行った。前年度と同様、火砕流跡地で土壌動物があまり得られなかったことから、火砕流跡地のような未成熟土壌は、土壌動物の生息環境としては不適、または侵入できても定着できにくい場である可能性が示唆された。 4）群集解析等： 口永良部島における既存の生物データを用いて、群集組成におよぼす噴火前の植生履歴と火山攪乱のタイプの効果について予備解析を行った。その結果、植生履歴と火山攪乱のタイプの双方が群集組成に影響をおよぼす可能性が示唆された。
  • 日本学術振興会：科学研究費助成事業 基盤研究(C)
    研究期間 : 2019年04月 -2022年03月 
    代表者 : 【代表者】澤畠 拓夫; 【分担者】早坂 大亮
     
    令和元年度は、１と２の課題であるアルゼンチンアリと在来アリとの餌獲得能力および消費量の違い、さらには３の課題の一部であるアルゼンチンアリの分配能力の違いについて研究を行った。１と２の課題研究の結果、アルゼンチンアリは、在来アリ類（トビイロシワアリ、クロヒメアリ等）に比べ，単位時間あたりにベイト剤へと動員するワーカー個体数が多かった．一方で，餌発見に要する時間，喫食した餌重量，および個体あたりの喫食した餌重量において，種間で明確な差は確認できなかった．アルゼンチンアリの３つのスーパーコロニー（J.main、神戸A、神戸B）間での比較では、スーパーコロニー間で餌資源の獲得能力は異なり、世界および日本で最も広域の分布域を獲得している集団J.mainが、少ない個体数で最大限の資源獲得を行っていることが示唆された。 ３の研究課題に関しては、次年度から行う予定であったが、これを繰上げ、本研究において新たなチャレンジングとなり研究の核ともなりうる、安定同位体を用いた餌分配能力の定量化についての研究、についての研究に着手した。これはアルゼンチンアリ及び在来アリ類のコロニーを採集し、ワーカーおよびブルードの安定同位体比を測定し、両者の値の違いから、餌分配の証拠を得ようというものである。現在、アルゼンチンアリのみ安定同位体比分析を実施することができている。結果、ワーカーの安定同位体比のばらつきに比べ、ブルードの安定同位体比のばらつきは小さくなることが判明した。これは、ワーカー1個体あたりが複数のブルードに餌を分配していることを示唆するものであり、餌の分配能力を定量化するための指標となりうると考えられる。
  • 河川区域で優占する有害・外来植物種子等の熱耐性に関する研究
    東亜建設工業：受託研究
    研究期間 : 2019年09月 -2021年03月 
    代表者 : 早坂大亮; 【分担者】澤畠拓夫
  • 環境省：環境研究総合推進費
    研究期間 : 2017年04月 -2020年03月 
    代表者 : 【代表者】五箇公一(国立環境研); 【分担者】早坂大亮(近畿大); 徳田 誠(佐賀大); 林岳彦(国立環境研); 角谷 拓(国立環境研)
  • 東亜建設工業：受託研究
    研究期間 : 2017年08月 -2019年03月 
    代表者 : 早坂大亮; 【分担者】澤畠拓夫
  • 日本学術振興会：科学研究費助成事業 挑戦的萌芽研究
    研究期間 : 2016年04月 -2018年03月 
    代表者 : 澤畠 拓夫; 【分担者】早坂 大亮
     
    侵略的外来種アルゼンチンアリの安定同位体分析は、広分布域集団で食性幅が広い傾向があったが、攻撃性との関連性は見出されなかった。本種による利用は、草本よりも樹木で顕著な傾向があり、樹木がアリマキなどの宿主として働き、本種の主な餌の供給源や越冬環境の提供者となっている樹種（シャリンバイ・ヤマモモ）の存在が明らかとなった。そして反対に、本種に利用されにくい樹種＝クス・イブキと草本種＝チガヤ・シバの存在も明らかにすることができた。今後は、アルゼンチンアリに利用されにくい樹種・草本種を優先して植栽した緑地環境づくりを進めることで、本種の増殖しにくい環境づくりが可能となると期待される。
  • 特定外来生物ゴケグモ属クモ類の根絶に向けた生態毒性学的研究
    農薬工業会：2016年度農薬の有用性・安全性に関する研究、教育活動支援奨励金
    研究期間 : 2016年09月 -2017年03月 
    代表者 : 早坂 大亮
  • 作用機序の異なるネオニコチノイド系農薬に対する水田生物多様性の応答メカニズム解明
    近畿大学農学部：平成27年度農学部特別研究費
    研究期間 : 2015年04月 -2016年03月 
    代表者 : 早坂 大亮
  • 津波に対する沿岸生態系のレジリエンスモデルの構築 -生物多様性に配慮した沿岸域環境保全管理に向けて
    三井物産環境基金：2011年度東日本大震災研究助成
    研究期間 : 2011年07月 -2014年03月 
    代表者 : 早坂大亮; 【分担者】島田直明(岩手県立大); 川西基博(鹿児島大)
  • 津波による海浜植生への生態影響と回復性評価
    国立環境研究所：平成23年度生物センタープロジェクト-震災対応センター型
    研究期間 : 2011年12月 -2012年03月 
    代表者 : 早坂 大亮
  • 津波に対する海浜植生の維持・回復機構の解明 -スマトラ沖大津波を事例として-
    日本科学協会：平成23年度笹川科学研究助成
    研究期間 : 2011年04月 -2012年03月 
    代表者 : 早坂 大亮

委員歴

  • 2021年09月 - 現在   日本緑化工学会   理事
  • 2014年03月 - 現在   日本雑草学会   編集委員
  • 2023年08月 - 2024年03月   環境省近畿地方環境事務所野生生物課   令和５年度琵琶湖外来水生植物防除試験アドバイザリー会議 委員
  • 2022年07月 - 2023年03月   奈良県 水循環・森林・景観環境部   外来生物対策アドバイザー
  • 2022年07月 - 2023年03月   環境省近畿地方環境事務所野生生物課   令和４年度琵琶湖外来水生植物防除試験アドバイザリー会議 委員
  • 2021年07月 - 2022年01月   環境省近畿地方環境事務所野生生物課   令和３年度琵琶湖外来水生植物防除試験等アドバイザリー会議 委員
  • 2018年08月 - 2021年09月   日本緑化工学会   評議員
  • 2013年11月 - 2021年09月   日本緑化工学会   編集委員会委員
  • 2017年10月 - 2019年09月   日本緑化工学会   第15期編集委員会 編集幹事
  • 2013年12月 - 2017年03月   環境研究総合推進費   アドバイザリーボード委員

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