Kazuhiro Katoh

The movement corridors for waterside animals, such as waterbirds, have been studied less than those of terrestrial animals. To clarify the role of rivers as movement corridors in urban areas, we investigated the movements of waterbirds in central Tokyo, Japan. This study was carried out around the Sumida River in the winter of 2019–2020. We divided...

In some urban parks in Tokyo, semi-natural habitat patches are maintained as nature reserves for birds, called bird sanctuaries. Bird censuses and vegetation surveys were conducted in eight urban parks in Tokyo from December 2015 to July 2016 to determine the effectiveness of bird sanctuaries on avian species composition. The relationship between a...

For the long-term survival of bird populations in urban areas, it is necessary to protect both bird habitats fragmented by urbanization and potential pathways for movement between them. However, urban pathways for waterbirds have rarely been studied. Suspecting that certain waterbird species that visit inland waters would tend to move along rivers,...

Volcanic eruptions can have significant impacts on plant and animal communities. Thus, it is important to understand the recovery process following these eruptions, particularly on isolated islands, in order to assist with biodiversity management and conservation. We studied relationships between vegetation structure and avian species composition o...

In habitats after natural disturbance, mutualistic interaction between plant and flower-visiting insects is critical for maintenance and recovery of communities. However, the detailed characteristics of the plant-insect interactions that occur after a natural disturbance remain to be identified. We investigated the network structure of these intera...

Ecological network is regarded as a possible way to improve biodiversity in urban landscapes. Though linear vegetated spaces such as greenways and wooded streets are often considered to be important components of urban ecological network, the ecological functions of such linear vegetated spaces have not been clarified well. In the present study, th...

Though factors influencing species composition in urban patchy woodlands have been studied, the ecological meanings of surrounding residential areas are still unclear. In residential areas in the Chiba City we surveyed relationship between bird species composition and land attributes such as vegetation structure and land cover considering landscape...

Vegetation corridors, such as street trees in urban areas, which connect patchy woodland and mitigate habitat isolation, are expected to enhance the persistence of birds in urban landscapes. However, the effectiveness of urban corridors on birds remains equivocal because vegetation corridor is often managed for human use with little consideration o...

Urban matrix is often considered to be an area contributing to urban biodiversity quite a little. Recent studies indicated, however, some small patchy habitat such as private gardens, pocket parks and other kind of small vegetative patches may support certain ecological communities. We surveyed avian species composition in 125 small (50 - 20,000 m2...

We report that some oedemerid beetles and longicorn beetles visited male flowers of the wild grapevine Vitis ficifolia var. izuinsularis on Miyake Island, off southeastern Honshu Island, Japan. We collected those beetles by beating inflorescences at night, though we had previously found no insects on the inflorescences in the daytime. We also used...

Recent studies have indicated that conditions of surrounding landscape matrix around a habitat patch can influence avian community in the patch. This fact suggests the importance of the permeability of habitat boundaries for bird individuals. In this study species composition of birds in and around woodland patches and that of birds crossing over t...

This work aims to analyse the response of epilithic diatom communities to environmental gradients in subtropical temperate southern Brazilian rivers to contribute to the development of a widely applicable methodology for water-quality monitoring. Samples for physical, chemical and biological determination were collected monthly, from December 2001...

管理されたクロマツ二次林の林床植生の復元にあたり，刈り取り残渣を用いることの有効性を把握すべく，刈り取り残渣の撒き出し実験を行った。地上植生の出現種のうち刈り取り残渣から発芽した種の割合は約30％と低かったが，地上植生で開花結実が確認された種の約60％は刈り取り残渣から確認された。刈り取り残渣には，発芽個体密度は既往文献より低かったものの，多種の草原生種が含まれた。地上植生と比較して，刈り取り残渣から発芽した樹林生種の種数は顕著に少なく，林外の人為攪乱地に生育する雑草種の密度は低かった。植生復元材料として刈り取り残渣を用いる際には，草原生種，樹林生種といった種群に応じて復元地へ導入しうる種の割合が異なることを踏まえ，より多数の復元対象種を再生すべくさらに研究を進める必要がある。

Satoyama is a traditional agricultural landscape in Japan. It contains many kinds of organisms, including endangered species. Satoyama is composed of several habitat types, including paddy fields, secondary forests, secondary grasslands, ponds, and streams. High species richness has been sustained in most habitats by anthropogenic disturbances of i...

Few studies have examined the relative importance of habitat loss and fragmentation caused by structurally complex matrices such as plantations. We examined the effects of the loss and fragmentation of the original deciduous habitat (secondary deciduous broadleaf forest) caused by a larch plantation matrix on bird occurrences in deciduous habitats...

Though many papers have been published on avian distribution in urban areas and on the factors that influenced species richness and / or composition of bird communities in urban habitats, no convenient measure of environmental evaluation of avian habitats along urbanization gradient has been developed. In the present study an environmental evaluati...

抄録 Biotope (habitat) type maps are essential as base maps for land use planning and biodiversity conservation. Actual vegetation maps are often used as the base maps, though important information for biotope evaluation such as vegetation structure and anthropogenic land modification is not shown enough. We proposed a procedure of biotope type mappi...

We examined the effects of stand, landscape, and spatial variables on bird communities in deciduous forests and Japanese larch (Larix leptolepis (Sieb & Zucc.) Gord.) plantations in a montane region of Nagano Prefecture, central Japan. We used plot-transect methods at 97 sites: 33 in winter 2003 and 18 sites were added in the 2004 breeding season i...

The vegetation of Miyake Island has been widely effected by the volcanic eruption in July 2000. This phenomenon is still going on and much of the vegetation cover has been changed. It is quite important to monitor the vegetation recovery process because of ecosystem study, prevention of disaster and rehabilitation of the Island. This study investig...

In this study, we tried selection the index species in frogs and toads, because it was necessary to verify the relation with the population density of the index species and the ecological location type in rural landscape planning. The fauna composition and seasonal changes in the number of frogs was investigated by visual encounter survey and audio...

Picris hieracioides var. japonica (Asteraceae), which grows in occasionally disturbed habitats such as riverbanks, is rarely observed under dense vegetation. We examined the effect of the experience and timing of receiving leaf-transmitted light in gap-detecting seed germination in this plant. Seeds under unfiltered light, which simulated the light...

Although the affinity to the matrix habitat (matrix affinity) determines the fate of species in dynamic landscapes where habitat replacement occurs, only a few studies have examined which ecological traits are associated with matrix affinity. Here, we examined the associations of five ecological traits (i.e., fertility, body weight, migratory behav...

Raising public interest in nature through conserving species of high social interest is crucial in achieving effective conservation of biodiversity. In Japan, the Genji-firefly Luciola cruciata (Coleoptera Lampyridae) in biodiversity rich agricultural landscapes called the satoyama has always attracted exceptional public interest. This study provid...

The influence of anglers on the feeding behavior of Greater Pied Kingfisher Ceryle lugubris was studied along the middle reaches of the Chikuma River, Honshu. Nests in Sakaki Town, Nagano Prefecture, around which the ayu fishing season began before fledging was completed, and in Nagano City, around which ayu fishing began after fledging, were compa...

To clarify the interrelations between various semi-natural grassland types (verge meadows, ditch walls, paddy levees, fallow fields, abandoned rice fields and farm roads) maintained by traditional agricultural management methods, we conducted vegetation investigation in a ‘Yatsuda’ rural landscape, and compared species richness between the grasslan...

Whereas matrix management has recently been suggested as a useful tool in biodiversity conservation, patterns and processes within matrices remain unknown. We examined the effects of the loss and fragmentation (configuration) of original deciduous habitats on birds in larch plantation matrix in the winter and during the breeding season in a montane...

From November 2001 to January 2002, wintering birds were censused in 30 urban woodlands in Chiba City, near Tokyo, Japan, to determine the factors other than habitat area, influencing avian species composition and diversity in urban woodlands. A group of species such as Sturnus cineraceus and Columba livia were more frequently observed in sparser w...

We examined relationship between avian diversity in urban woodlots and the surrounding environment. We surveyed bird communities and vegetation structures in 9 woodlots (6.87-52.26 ha) in Tokyo Metropolis and Saitama Prefecture during both wintering and breeding seasons in 2005. We measured area, latitude, and longitude of each woodlot by GIS, and...

We examined how vegetation structure and human activities influenced avian fauna in wooded open spaces in urban areas. Canonical Corresponding Analysis (CCA) revealed that factors such as coverage of lawn, pressure of human-utilization, and coverage of deciduous trees were important to determine avian fauna. Areas covered with lawn and used by peop...

Genji-firefly Luciola cruciata, a symbolic species in Japanese traditional agricultural landscapes, has recently been decreased. Therefore, conservation practices of this species have been tried in various parts of Japan. It was reported that the factors influencing the distribution of this species in eastern Japan differed from those in western Ja...

Few studies have compared the relative importance of stand-level variables and landscape-level variables for wildlife in low-contrast landscapes in winter. We examined the influence of stand and context variables on bird communities in a rural landscape in Japan. Line transect surveys were conducted during the 2001 wintering season in 25 coppice an...

The aim of the present study is to develop a new learning material for learning of the relationship between biota and habitat environment including anthropogenic disturbances, using numerical models representing the relationship. We made ordination of our field research data using multivariate analysis, followed by development of a simulation progr...

Although Eupatorium japonicum Thunb. is a threatened plant species in Japan, conservation ecological studies on it have not been enough for conservation practices. Conservation of threatened plant species requires information on seed germination and soil seed bank. In the present study, we conducted germination tests with gradual temperature method...

帰化植物の繁茂は生物多様性の消失の主要因ともなるものの，それに関する生態学的研究例は極めて乏しい。本研究では，永続的埋土種子集団の形成可能性を含めた植物の多くの生態的特性のうち，どの性質が帰化植物としての定着に寄与しているかを分析することを目的として，比較生態学および種子の永続性に関するデータベースに含まれる我が国における帰化植物を抽出した。それらを用いた分類樹木による解析結果において，攪乱依存性および種子の永続性は帰化植物として帰化定着する際に重要な生態的特性であることが明らかになった。そのため，帰化植物による永続的埋土種子集団の形成はそれらの駆除において大きな障害になると言える。

In order to suggest desirable openspaces in terms of biodiversity in urban riparian, it was studied that relationship between wintering avifauna and habitat structures and landuse around study sites. 24 study sites were located on 2 urban riparian areas in northwest part of Chiba Prefecture, Japan. As a result, significant negative correlations of...

The Genji-firefly (Luciola cruciata) is an endemic insect of high conservational interest. We discussed relations between the abundance of the adult L. cruciata and land covers in agricultural landscape in southeastern Tochigi prefecture, Japan. The abundance survey was conducted during the adult period of June at 35 observation points where aquati...

Field surveys on plant species richness and soil chemistry were carried out at 30 study sites in “Satoyama” deciduous forests and coniferous plantations in Ichikai Town, Tochigi Prefecture, Japan. In deciduous forests, tree (height > 1.5m) species richness showed significant positive correlation with the period after abundance of vegetation managem...

Multivariate analysis of ecological data has been applied to environmental analysis and evaluation. Recently, some ecologists reported that classification and regression trees (CART) are ideally suited for the analysis of complex ecological data. We use classification tree to analyze the relationship between avian species composition and habitat co...

Jungle crows (Corvus macrorhynchos) have increased in number in urban areas across Japan, creating various kinds of problems. In the present study, jungle crows were counted at 33 study plots located in large open spaces (>10 ha) in central Tokyo to clarify the role of urban open spaces in crows' daily flying. Three types of open spaces were recogn...

In order to clarify the distribution pattern of soil seed bank and dispersion of seeds by river water flow, germination test were made by applying the surface soil collected from four sites (main channel side, bank marsh, remnant channel, bank lowland) in floodplain of River Arakawa. The abundance of seed banks in back marsh site is relatively less...

河川における一次生産の多くを担いながら, 河川環境の保全や回復の際にはほとんど省みられない付着珪藻類に注目し, その種組成がどのように変動しているかを検討した。青梅市内の多摩川で調査を行った結果, 珪藻群集の種組成は, 主に水域の形状に対応して変化していた。その背景には, 水の化学性の空間的な不均一性があると推定された。付着基物や水際の植生, 水文学的条件も, 付着珪藻群集に影響を及ほしてはいたが, その程度は小さかった。多様な珪藻群集を維持するためには, 主流路の環境を多様にするだけでは不十分で, 通常は主流路からの流入がない池や, 伏流水の湧出, たまり水など, 自然な川原では普通に見られる多様水域が必要である。

Grazing control has been reported to be effective for the control of desertification in semi-arid regions. However, economic reasons often make complete inhibition of grazing (complete exclosure) difficult to carry out. Grazing control has been applied to the Kerqin Sandy Lands, Inner Mongolia, China, by means of seasonal exclosure, whereby grazing...

生物多様性は全ての生物に関わる問題であるが, 微生物を対象とした生物多様性の保全の研究はまれである。本研究では, 河川の付着微生物の中でも優占的な存在である付着珪藻類を対象として, 水文学的条件などが種多様性にどのように影響するか検討した。流路から切り離された止水域には, 本流とは異なった種組成の珪藻群集が見られ, その原因として, 水質汚濁以外の理由による水の化学性の違いが考えられた。流路では, 流速が遅いほど種多様性が高かった。結果に基づき, 珪藻類にとって川沿いの止水域が流路とは異なった性質の生息場所となるための条件と, 流速が多様な流路を確保する重要性を考察した。

樹林地内部の植生の種組成が鳥類の分布にどのような影響を及ぼしているか明らかにするために, 武蔵野台地および狭山丘陵に位置する比較的規模の大きな樹林地において, 鳥類の分布と植生の種組成の対応関係を調査した。 それぞれの樹林地に植生の異なる複数の調査地点を設定し, 1994年の繁殖期に鳥類の個体数調査を行った。 その鳥類調査地点内に方形区を設定し植生を調査した。 調査結果から, 樹林性の種の中には, ヤブサメやメジロのように, 常緑樹林への遷移が進行している二次林を特に好む種があることが明らかになった。 また, 林床植生の貧弱な二次林には, 草地や疎林の環境に現れる鳥類が侵入することが示された。

Bird communities on the 20 fragmented woodlots in a suburban area were surveyed in the Tokorozawa City, Central Japan, to analyze the factors that influenced the distribution of birds. Our results showed that woodlot area is an important predictor of the number of individuals and the species richness of birds in each woodlot. Based on the species c...

Ecological analysis is essential for environmental assessment and planning. Based on ecological analysis we can recognize the ecological situation of the study area, and understand how environmental factors should be controlled to improve the ecological situation. Biological indicators have often been referred to in case of environmental evaluation...

Multivariate analysis of species-compositional data has been recently used to clarify the compositional change pattern of ecological communities, to find out major environmental factors influencing ecological communities, and to support environmental monitoring and planning. Among multivariate approaches, ordination was studied in the present study...

1. During the spring of 1992, fifty-two quantitative diatom samples were collected from twenty-eight rivers located in the Tokyo Metropolitan area, Japan, to study the response of the diatom assemblages to water pollution (assessed using physical and chemical data determined monthly from April 1987 to March 1992). 2. Species composition was analyse...

孤立樹林地内部の植生構造が鳥類の分布にどのような影響を及ぼしているかを明らかにするために, 埼玉県所沢市の比較的面積の大きな孤立樹林地において鳥類の分布と植生構造の対応関係を調査した。樹林地を植生によっていくつかの林分に分け, それぞれの林分において点センサス法による鳥類群集調査を行った。既往の研究の多くは鳥類の繁殖期に調査を行っているが, 本研究では越冬期に調査を行った。植生構造は各階層の植物体量と胸高断面積によって把握した。その結果, 越冬期においても鳥類の種数は植物体量と有意な相関が見られた。鳥類の分布は, 全階層の植物体量と低木・草本層の植物体量枯れ木の胸高断面積と関係があることがわかった。

埼玉県所沢市内のコナラニ次林内で木本種の分布を調べ, 二次林の空間的な構造とそれに関与する要因を考察し, 二次林の遷移管理のあり方を検討した。二次林内には個体サイズの大きいシラカシの実生・稚樹や低木が多く確認され, 管理が放棄された場合シラカシ林への遷移が進む可能性が高いことがわかった。一方アオハダ, イヌシデ, エゴノキは亜高木から低木, 稚樹の各層で多くの個体が確認され, 一時的にもこうした種が優占する林分が出現する可能性が示唆された。また多くの種で空間的な分布が不均一であることがわかった。二次林のこのようなパッチ状の構造は, 今後二次林の植生管理を考慮する際に注目すべきものと考えられる。

Historical and recent land degradation has been caused by human activities in semi-arid Kerqin Sandy Lands, Inner Mongolia. The purpose of the present study is to outline the process of land degradation in this area and to assess the efficiency of desertification control measures on recuperating process of vegetation cover. Historical documentation...

各種の自然環境調査で生物相が調査されるが, その結果の分析と利用は現状では十分とは言えない。本研究では, 多変量解析により生物相の調査結果を分析し, 各種の応用に供し得ることを示す。多変量解析の適用のために, 分析の前提条件が少ない分類型の多変量解析を出発点とし, 正準判別分析を併用することにより, 生物相の分類と優占的な環境傾度の抽出を行う手順を提案した。この方法は, 将来的には生物相の予測にも利用できる。河川中流部の底生無脊椎動物相を対象とした事例研究では, 水質がほぼ一様な場合の, 流速や堆積物の粒径などの物理的条件の重要性が指摘でき, これらの多様性を確保する必要性が示唆された。

The correlation between the algal cell density and the growth form of freshwater epilithic diatoms was investigated in field observations. Three sampling stations were set in the Asa-Kawa River, Japan to examine the possible effects of water pollution on the correlation. The developmental process of epilithic algal communities reported by some prec...

Some ecological methods of evaluation of water pollution, including biotic indicesand correspondence analysis, which is a kind of multivariate analysis, were comparedusing diatoms and benthic invertebrates as indicator organisms. Though diversityindices have been used for environmental evaluation in some previous works, the present work showed thei...

本研究は, 埼玉県狭山市において, 鳥類と土地利用の分布を比較し, 鳥類の分布を規定している要因を検討したものである。その結果, 鳥類は樹林型, 水辺型, 中間型の3つのグループに分けられ, 樹林型と水辺型の鳥類の種類は, その生息地の面積比の増加とともに増えることがわかった。中間型の鳥類は, いくつかの空間要素にまたがって生息していることが示唆された。また, 鳥類の分布からみた狭山市の空間区分を行い, 鳥類保全の視点からの生態環境管理計画の可能性について検討した。

Spatial variation of attached diatom assemblages was surveyed in an unpolluted river, the River Saguri in Niigata Prefecture, Japan, and the causes of the observed variation were analyzed. The result of cluster analysis indicated that the spatial variation of diatom assemblages was correlated to stream order and current velocity. Relative abundance...

Environmental factors affecting the species composition of periphytic diatom assemblages were analyzed in the partly polluted Asa River, in Tokyo, Japan, using principal component analysis, individual differences scaling and direct gradient analysis. The effects of water pollution, seasonal change of temperature, and substrate were detected, among...

快適な水辺の創造のための環境管理では, 水域の生物群集を正当に評価し, これを健全に維持するための配慮を加えることが重要である。本研究では, 生物指標および生物群集情報の多変量解析により, 水辺環境の管理指針を得るための方法を検討した。生物指標は指標生物および算定手法によって性質が異なるので, その組合せにより評価対象水域の環境の異なった側面を評価できる。多変量解析により, 対象水域の生物群集が影響を受けている環境条件を知ることができる。これらの結果を地図情報と対応させて, 水系を生態的に均質な部分に分割し, 環境管理の基本単位とすることも考えられる。以上の手法について, 東京都の河川への適用例とともに報告する。