Tokyo University of Agriculture Repository / 東京農業大学リポジトリ
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Effectiveness of Camera Trap Data as Relative Abundance Index of the Raccoon (Procyon lotor)
Get PDFアライグマ(Procyon lotor)の密度指標として捕獲効率(CPUE)が有効であることはすでに知られているが,このデータは捕獲作業を実施しなければ得られない。そこで,自動撮影データから得られた諸指標[撮影効率,撮影するのに要した期間(LTD),撮影メッシュ率]を捕獲効率と比較することによって,自動撮影データの密度指標として有効性を検討した。アライグマの生息状況が異なる神奈川県内の3地域の林地を主な調査地として,2010-2011年に自動撮影調査を行った。捕獲効率,捕獲するのに要した期間 (LTC)および捕獲メッシュ率は,行政による防除事業データから算出した。これら指標を地域間で比較すると,撮影効率,撮影メッシュ率,捕獲メッシュ率は,捕獲効率と同様の傾向を示したが,LTDとLTCはそうではなかった。一般化線形混合モデルにより解析したところ,撮影効率は捕獲効率に対して有意な正の関係がみられたが,LTCにおいてはみられなかった。これらのことからアライグマの密度指標として,撮影効率は有効であった。For assessing the relative abundance of the raccoon (Procyon lotor) in Kanagawa prefecture, Japan, during 2010-2011 we conducted camera trap survey at three forested areas. This was compared with capture records of the raccoon under the removal project of the same period. Through camera traps we obtained 1) relative abundance index (RAI), 2) latency to first detection (LTD), and 3) distribution of presence and absence meshes 1km×1km (DPM). Through captive records in the removal project, we obtained 4) number of catch per unit effort (CPUE), 5) latency to first catch (LTC) and 6) catch of presence and absence meshes 1km×1km (CPM). Since CPUE has been identified as a reliable index of relative abundance of the raccoon, other indices at these areas were compared with respective CPUE. Although indices RAI, DPM and CPM showed similar trends with CPUE, LTD and LTC did not. Influence of RAI and on CPUE and CPM, through generalized liner mix model analysis showed that RAI has positive effect on CPUE. The Influence of RAI on LTC was not clear. The present result indicated that RAI of camera trap was valid for the abundance index of raccoons.E2KJ00009949979論文Articl
Lasiodiplodia Pod Rot of Theobroma cacao L. Caused by Lasiodiplodia theobromae
Get PDF2005年5月,東京都小笠原村父島で施設栽培されていたカカオの果実に,初め茶褐色～暗褐色の不整病斑を生じ,のちに拡大して腐敗症状を呈する病害が観察された。その罹病部からはLasiodiplodia属菌が高率に分離され,分離菌を用いた接種試験により原病徴が再現され接種菌が再分離された。分離菌は,暗褐色から黒色の分生子殻内に,隔壁の無い側糸と,後に完熟すると2胞,暗褐色で縦縞模様をもつ分生子を形成することから,Lasiodiplodia theobromae (Pat.) Griffon & Maubl.と同定した。さらにrDNA内のITS領域を用いた分子系統解析の結果からも同定を裏付ける結果を得た。小笠原で商業的に栽培されているパッションフルーツ,パパイア,バナナ,マンゴーを用いた宿主範囲の検討では,パパイア,バナナ,マンゴーにおいて病原性が確認された。これまでカカオにおける本病害は日本において報告がないため,Lasiodiplodia果実腐敗病(英名 : Lasiodiplodia pod rot)と命名したい。Severe pod rot of cacao, Theobroma cacao, was observed at Chichijima, Bonin Islands, in May, 2005. The causal fungus was identified as Lasiodiplodia theobromae (Pat.) Griffon & Maubl. based on the morphological characteristics, inoculation experiments, and molecular phylogenetic analysis. Among the four tropical fruits cultivated in the Ogasawara Islands, cacao isolate showed clear pathogenicity on banana, mango and papaya fruits but not on passion fruit. This is the first report of Lasiodiplodia pod rot (kajitsufuhai-byo in Japanese) on cacao pods caused by L. theobromae in Japan.E6KJ00005049280論文Articl
Comparison of Earthworm Communities between Conifer Plantations and Broad-leaved Secondary Forests
Get PDFスギやヒノキ等の針葉樹の単一樹種からなる人工林では,生物相が単純になることが指摘されている。そこで本研究では,森林施業とミミズ群集の種多様性との関係を明らかにすることを目的とし,静岡県富士宮市麓および東京都西多摩郡奥多摩町のヒノキ人工林,スギ人工林,広葉樹二次林のミミズ群集について調査を行った。両調査地において,広葉樹二次林で最も種数と種多様度が高く,次いでスギ人工林であった。また,両調査地で最も種数が少なかったヒノキ人工林で出現した種は,広葉樹二次林,スギ人工林でも共通にみられる傾向にあった。各林分では,上木の種類,土壌物理化学性などの環境要因が異なることによって,ミミズの種組成や,個体数密度に影響を及ぼすと考えられた。特に,今回の調査結果からはミミズが生息する環境要因の一つに,リターの堆積量と質及び下層植生の種類と量が関わっていることが示唆された。It is well known that artificial monoculture forests, such as Sugi (Crypotomeria japonica) and Hinoki (Chamaecyparis obtusa) forests, have low biodiversity. The objective of this study is to examine the effects of forest management on earthworm diversity, and earthworm communities were compared among living Hinoki, Sugi and broad-leaved secondary forests in two sites, Fujinomiya city, Shizuoka Prefecture and Okutama, Tokyo Prefecture. In both sites, broad-leaved secondary forests had the highest diversity among the three forest types, and Hinoki forests showed the lowest. Species which occurred in Hinoki forests commonly appeared in the other forests. It was concluded that the species composition and individual density of earthworm communities were influenced by vegetation and soil physicochemical qualities. Especially, the amount and quality of litter and species diversity and biomass of understory plants are important factors for the habitat evaluation of earthworms.E8KJ00005049282論文Articl
A Simple and Timesaving Method of Measuring the Distribution Density of Glandular Trichomes on Sweet Basil (Ocimum basilicum L.) Leaves
Get PDFスイートバジル葉の簡易な腺毛分布密度計測方法を検討するために,葉面積の拡大がみられなくなった完全展開葉を,基部,中部,先端部に分割して,各葉片の腺毛分布密度と葉全体の腺毛分布密度を比較した。その結果,主枝の下位節葉,中位節葉,上位節葉のいずれにおいても,先端部から基部に向かうほど腺毛分布密度が高いことが明らかになった。また,中部葉片の腺毛分布密度と葉全体の腺毛分布密度がほぼ一致した。すなわち,完全展開葉においては,主脈を境に葉を分割した半葉の中部葉片の腺毛分布密度を葉全体の腺毛分布密度とみなすことができる。また,それをもとに中部葉片と葉全体との面積比率および中部葉片の腺毛数から葉全体の腺毛数を推定することができる。The aim of this study was to devise a simple and timesaving method of estimating the trichome density on sweet basil leaves. Fully expanded leaves, sampled from upper, middle and lower nodes on the main axis, were cut into two halves along the midrib, and both halves were further divided into three leaf parts at the point of equal midrib length perpendicularly to the midrib. The distribution density of glandular trichomes on the abaxial side of these leaf parts of either halves tended to decrease according as the distance from the base increased. The glandular trichome density in the middle leaf part coincided with that measured for the entire leaf. Thus, the glandular trichome density in the middle leaf part can be used as a reliable estimate of that on the entire leaf. This method can save time by about 70% as compared with counting out the glandular trichome density on the entire leaf. In addition, multiplying the glandular trichome density on the middle leaf part by the area of the entire leaf relative to that of the middle leaf part can give a close estimate of the total number of glandular trichomes on the entire leaf.E4KJ00005049263論文Articl
Study on Gravel Transfer and Supply in a Kushiro River basin, Hokkaido Japan, the Spawning Site for Japanese Huchen (Hucho perryi)
Get PDF北海道東部の緩蛇行河川において,サケ科魚類イトウHucho perryiの産卵床は,蛇行区間の崖が洗掘され,堆積したと思われる河床の礫底に造成される傾向にある。そこで本研究においては,崖が存在する蛇行区間と崖が存在しない蛇行区間の物理環境を測定し,礫の供給が崖に依存しているか否かを調査した。結果,両蛇行区間の比較において,川幅,流速,半径に有意差はなかったが,水深は崖のある蛇行で有意に浅く,礫サイズも崖のある蛇行で有意に大きかった。また融雪増水時に投入した礫に移動が認められなかったことから,礫の供給は上流域からではなく崖が洗掘されることにより供給されるものと推定された。In eastern Hokkaido, Kushiro river basin where the redd of japanese huchen is observed, the river cliff eroded, and gravel accumulated. In this study, the physical environment was measured in order to examine just how the river precipice is the supply source of the gravel. As a result, no significant differences were indicated in the river width, velocity and the radius but the river depth in the meander with river cliff is significantly shallower than the one without river cliff and the size of gravel in the meander with cliff is significantly larger than the one without river cliff. Additionally, there was no obvious migration of gravel by freshet of snow melting. In conclusion, it was extrapolated that the gravel was provided not from upstream but by the eroding of the river cliff.E15KJ00005049274短報Not
Application of Willingness to Pay Concept to Forest Management in Kosuge Village
Get PDF補助割合の低下,労働賃金の高騰,素材生産コストの増加,木材価格の低迷,そして大量の外材輸入は,小菅村だけでなく日本全体の木材生産や森林管理が停滞している原因となっている。そこで本研究では,山梨県小菅村において木材生産や森林管理を適切に行うための住民の意識や支払い意思額を調査し,それをもとに森林管理への貢献や適用がどのようにできるかを試みることにした。調査は,全家族(367)の13%にあたる48家族を抽出し,その家族に対して聞き取り調査を実施した。調査内容は小菅住民の支払い意思額を求めるために,仮想市場評価法による2者選択とその選択内容の追跡項目を設定した。調査の結果,住民は森林に対する高い重要性を認識し,森林の機能の向上と森林保全活動に対する支払い意思が示された。そして,1家族あたり平均1,259円の支払いを確認でき,支払い意思額の平均は,1,125円となった。そして,結果をもとにした森林管理の可能性について検討した。The fixed government financial support, rising labour and operation costs, and falling wood price coupled with high influx of foreign wood products are influencing forest production and management in Kosuge and Japan as a whole. The research aimed at finding a workable strategy for forest production and management in order to enhance benefits in Kosuge Village by using the contingent valuation method (CVM) to investigate the willingness of residents to contribute to forest management and analyzing its implications on forest management. The study was carried out in Kosuge Village in the Yamanashi prefecture. In all, 48 house-holds representing about 13% of total house-holds were surveyed. Data was collected using face-to-face interview. The CVM, using the referendum dichotomous choice approach with a follow-up was employed to obtain information about the willingness to pay (WTP) of the Kosuge residents. The findings revealed that the residents were aware of the benefits of forest, and indicated their willingness to participate in a program aimed at improving forest and hence their readiness to pay a premium. Thus, the mean WTP per month of each household was \1,259 and the median WTP was \1,125. The study therefore provides decision makers with information that residents are willing to make monthly contributions to forest improvement programs. The results of applications to forest management system were also taken into consideration.E7KJ00005590579論文Articl
Evaluation for Landscape on Garden Path by using Fractal Analysis and Positioning<BR>-Example by Koishikawa Koraku-en Garden and Rikugi-en Garden-
Get PDF本研究では回遊式庭園における園路景観の定量評価手法の開発を目的とし,江戸時代の代表的な大名庭園である小石川後楽園及び六義園を対象とし,園路の位置計測ならびに景観に対するフラクタル解析を行った。園路の位置計測では,両庭園に対する園路の平面位置および高さの変化を比較した。その結果,両庭園における高さ変化の標準偏差は小石川後楽園が±0.811m,六義園が±0.286mと小石川後楽園が特に園路の高さ変化に富んでいることが確認された。また,両庭園の園路長に対して同一の尺度にて比較を行った場合,両庭園の位置や高さの変化には類似性が見られた。さらに,フラクタル解析により両庭園における園路上の景観を評価した結果,園路の位置や高さと景観の変化とは関連性が高いことが確認され,位置計測およびフラクタル次元が日本庭園における景観に対する定量的評価の指標となる可能性を示唆した。This paper investigates development of quantitative evaluation method for the landscape of circuit style gardens. The examples of circuit style gardens adopted in this investigation were Koishikawa Koraku-en and Rikugi-en, and measurement of positions on the garden path and fractal analysis were performed for both gardens. To obtain the results, the standard deviation for the altitude of both gardens path were compared, and it could be confirmed that Koishikawa Koraku-en has difference of altitude larger than the Rikugi-en (Koraku-en : ±0.811m, Rikugi-en : ±0.286m). In addition, the results of measurements in both gardens were also compared and in the same distance of each garden path, the variations of position and altitude showed the same tendency. Furthermore, the landscapes of each garden path were evaluated by fractal analysis, and relation of position and landscape could be confirmed. Consequently, it is expected that the measurement of positions and fractal analysis will become part of the index of quantitative evaluation for landscape in Japanese gardens.E2KJ00005764600論文Articl
Effects of Pulling-up and Soil Coverage on Establishment of Asiatic Plantain (Plantago asiatica L.)
Get PDFオオバコは畦畔および農道では旺盛に繁殖するが,耕起地では繁茂しないことが知られている。その要因を解明するため,オオバコおよび比較植物としてメヒシバ,オヒシバおよびスベリヒユを用いて,耕耘を想定した引抜き,埋没処理に対する再生反応,および耕耘後の種子再生産能力推定のための播種期別生殖成長到達日数について検討した。実験1として,3および5葉期の個体を引抜き後,あるいは引抜かずに,それらの個体を深さ2および6cmに土壌で埋没した。対照区には,引抜きおよび埋没をしない区を当てた。その結果,6cmの埋没区においては,引抜きの有無,処理の時期にかかわらず4種とも全く再生しなかったが,2cmの埋没区では,再生程度に著しい種間差があった。オオバコでは無引抜き区において,対照区の3%(3葉期処理)∼17%(5葉期処理),スベリヒユでは引抜き区で3%(3葉期処理)∼27%(5葉期処理),無引抜き区で13%(3葉期処理)∼27%(5葉期処理),メヒシバでは引抜き区および無引抜き区それぞれ3%(3葉期処理)∼7%および20%(5葉期処理),オヒシバでは5葉期の引抜き区のみ3%が再生した。再生個体の草丈は,オオバコにおいて劣った。実験2として,5∼7月に播種したところ,7月播種のオオバコのみ当年内には生殖成長に至らなかった。以上のように,オオバコ個体は耕耘時に土壌から引抜かれ,土壌中に埋没されると全く再生できず,引抜かれなくても土壌埋没によって再生が劣り,草丈も低く,さらに,季節的に遅く出芽した個体では種子生産が当年内に行われず,耕地において生活環の完結が困難になるものと推察された。Asiatic plantain (Plantago asiatica L.) grows thickly and rapidly in levees and farm roads, but not in cultivated fields. We clarified the non-adaptability of Asiatic plantain to fields that had been plowed for management.Generally, plowing pulls up, cuts, and buries plants under the soil. The experiment described herein investigates regrowth responses against artificially simulated “pulling-up” and “soil covering” caused by plowing. Assuming that germination from buried seeds occurs after plowing, florescence occurring within a year from seed sowing was examined. Asiatic plantain was examined along with upland weeds : hairy crabgrass (Digitaria adscendens (H.B.K.) Henr.), goosegrass (Eleusine indica (L.) Gaertn.), and common purslane (Portulaca oleracea L.).Plants in three-leaf and five-leaf stages were pulled up and covered with 2cm or 6cm deep soil. For comparison, plants that had not been pulled up were treated without soil covering (established plants hereinafter).Results show that none of the four plants with soil covering thickness of 6cm regrew. However, with 2-cm-thick coverage, considerable differences were apparent among species. Regarding Asiatic plantain, only 3% (three-leaf stage treatment)-17% (five-leaf stage treatment) of established plants regrew. Regarding common purslane, 3% (three-leaf stage treatment)-27% (five-leaf stage treatment) of the plants regrew when pulled up ; 13% (three-leaf stage treatment)-27% (five-leaf stage treatment) of plants regrew with no pulling-up treatment. For hairy crabgrass, 3% (three-leaf stage treatment)-7% (five-leaf stage treatment) of plants regrew with pulling-up treatment ; 20% of plants regrew in the five-leaf stage with none in the pulling-up treatment. Furthermore, only 3% of the goosegrass pulled up at the five-leaf stage regrew. The regrown Asiatic plantain plant length was considerably less. Of the four species sown in May, June, and July, only the Asiatic plantain did not flower within the year sown in July.As described above, Asiatic plantain, once pulled up from the soil, is unable to regrow. Plants that are covered with soil, even if established, are very small. Seedlings that germinate in the late season (summer) have insufficient time to produce seed. These results underscore that Asiatic plantain cannot complete its life cycle in a frequently plowed field.E3KJ00005764601論文Articl
A Development of the Real-time Monitoring System for Internal Air Conditions of Container for Long-Term Marine Transport of Foods
Get PDFコンテナを用いた食品の長期海上輸送では,不適切な空調により食料品に荷傷みが発生したとしても発生状況の特定が困難であり,責任の所在が不明確な場合が多く,トレーサビリティや食の安全に関わる問題を有している。そこで本研究では,センサネットワーク技術を用いたリアルタイム温湿度計測システムを開発し,コンテナによる長期海上輸送における空調状況を衛星通信とインターネット経由で監視する簡易技術を開発した。このシステムを実際のコンテナに搭載し,2008年11∼12月の期間,東京·ドバイ航路にて実証実験を行った。その結果,シンガポール港における積み替え時においてコンテナ内部の異常な温湿度上昇を検知するなど,提案するシステムが異常検知に効果的であることが確認できた。しかし,イリジウム衛星によるデータ通信では通信エラーが連続して発生する場合もあり,対策が必要なことを確認した。Since the immediate detection of the damage to foods due to inadequate control of air condition in container is not an easy task and responsibility for any trouble is usually unclear, the transportation of agricultural products overseas from Japan is known to have problems concerned with traceability and food security. In order to find a solution to this problem, the authors have developed a real-time monitoring system of internal air conditions of container through satellite communication and the Internet using sensor network technologies for long-term marine transport of agricultural products. In this paper, we report on the experiment of marine transportation to Dubai from Tokyo in the period of November to December, 2008. Throughout the experiment, it is validated that the present system is one of the most cost-effective real-time monitoring systems and the system could successfully detect a rapid change of temperature and humidity of the container in transshipment at Singapore Port. However, a series of data communication errors often occurred and it was understood that improvement in establishing stable data communication by Iridium satellite must be one of the important future subjects of this study.E5KJ00005764603論文Articl
The Asiatic Plantain (Plantago asiatica L.) Growing in Paddy Field Levee has Distinctive Seed Germination Characteristics
Get PDF水田畦畔において,オオバコは土壌流亡の防止,緑環境の維持の役割を担っている不可欠な植物の一種である。そこでは,畦畔管理としての刈取り作業が実施される。種子でのみ繁殖するオオバコにとって,刈取りは生殖成長・種子繁殖の制限要因となるが,現地では刈取後に幼植物の繁茂が観察される。これには表層土に存在する種子からの発芽・成長が考えられ,水田畦畔では種子の休眠性が弱いことが想定される。そこで,オオバコ種子の発芽特性を,水田畦畔を含む複数の生育地から採取した種子を用いて比較検討した。さらに,水田畦畔および踏み跡広場で生育しているオオバコから採取した成熟種子の季節的出芽特性を比較した。これらの結果をもとに,水田畦畔に生育するオオバコ種子の発芽特性を,刈取りに対する適応性の観点から検討した。その結果,水田畦畔から採取したオオバコ種子はいずれも90%以上の高い発芽率を示した。また,採種時期にかかわらず播種直後に速やかに出芽した。一方,踏み跡広場から採取した種子では,7月中旬に採取した種子は出芽率が低く,秋採取の種子は出芽に遅延がみられ,秋から初冬に採取した種子は播種直後には全く出芽せず,翌春に再出芽あるいは出芽するなど,種子出芽特性にかなり大きな季節変動が示された。以上から,水田畦畔に生育するオオバコの成熟種子は採種場所や採種時期にかかわらず,発芽好適条件下では速やかに発芽できることが判明した。このことから,オオバコは水田畦畔においては,刈取りによって既存植生が一時的に疎となり,地際の光強度が強まる条件で,湿潤な土壌環境を利用して速やかな出芽が可能である特性を有するものと推察される。In paddy field levees, the Asiatic plantain is a necessary plant that supports prevention of soil run-off and maintenance of a green environment. At such places, grass mowing is done as farmland management. For the Asiatic plantain, which reproduces solely from seed, mowing could negatively affect generative growth and seed propagation. Despite this potential damage, thickly regrown seedlings can be observed soon after mowing operations. This rapid emergence response of the plant indicates that many seeds of this species exist in and on the soil. It is assumed that the seed dormancy is weak in the paddy field levee. Thus, the seed dormancy of the Asiatic plantain was investigated using seeds in many growing locations including paddy field levees. Furthermore, seasonal germination characteristics of the Asiatic plantain seed in a paddy field levee were compared with those in other areas (an open land), thereby clarifying the germination characteristics of this plant's seeds. Based on the results obtained, the adaptability for mowing of the Asiatic plantain seed in the paddy field levee was examined.Consequently, the seed collected from the paddy field levee showed a high germination percentage of greater than 90% without exception, and the ratio of dormant seeds was small. Regarding the seeds of plants grown in open land, the emergence varied among seasons : seed collected in mid-July showed a low emergence rate and that in autumn a delayed emergence. The seed collected in the open land during late fall to early winter was unable to emerge soon after sowing, but emerged in the following spring.These results show that, regardless of the seed production season, the mature seeds of the Asiatic plantain growing in paddy field levee can germinate immediately after sowing under environmental conditions suitable for germination. Therefore, it is considered that the seed grown in a certain place begins to germinate in response to full sunlight exposure on the moist soil after mowing, and thereby the Asiatic plantain can succeed its life cycle in the paddy field levee.E6KJ00006055384論文Articl