Abstract The change in fish fauna was monitored ponds within irrigation systems Iwate prefecture, north‐eastern Japan to evaluate the effectiveness of eradicating invasive piscivorous largemouth bass, Micropterus salmoides . Eleven study were categorized into three pond groups: bass‐dwelling ( n =3), bass‐eradicated =3) and non‐invaded =5). Species richness diversity, which temporally decreased ponds, increased ponds. Furthermore, mean numbers topmouth minnow freshwater goby gradually...

Ecological resilience to ungulate overbrowsing is an important issue in forest ecosystems. After chronic herbivory, the recovery rate of understory vegetation and its related functions can be slow even with decreasing grazing intensity; thus, detecting elasticity during alternative successional trajectories fundamental understanding state perturbations. In this context, we focused on physical plant-soil feedback (functional interactions between plant growth soil conditions) evaluated...

Stopping biodiversity loss due to human activities is of great concern for ensuring ecosystem services sustainable development. While species-habitat relationships are an important aspect species conservation, considering interactions remains challenging in habitat suitability modelling the complex nature species' ecology and uncertainties present ecological data. To cope with this challenge, a Random Forests (RF) multi-class classifier built using data set comprised monthly fish surveys...

Summary Understanding the mechanism governing movements of stream‐dwelling fish is a fundamental issue associated with diverse range ecological processes. We examined movement pattern small benthic species, L efua echigonia , using mark–recapture technique in headwater streams. Our main objectives were as follows: (i) to assess and direction . ; (ii) examine how biotic abiotic factors affect emigration immigration patterns (iii) at stream scale. Stationary accounted for greatest proportion...

Abstract Riparian fluvial systems are used for the irrigation of rice. This practice has led to an increasing need conserve biodiversity these riparian against intensification rice systems. study examined underlying processes that structure fish community assemblages in a traditional system and how might inform conservation programmes. Sampling was conducted at 26 reaches permanent channel September December 2007 May 2008. The relative roles niche versus dispersal were determined by...

The Amur three-lips (Opsariichthys uncirostris uncirostris) is an endemic subspecies in Japan and native to the river systems of Lake Biwa–Yodo River. population Biwa has decreased, primarily due habitat degradation introduction by competitive, non-native predators, such as largemouth bass (Micropterus salmoides). However, effects on are unclear. We investigated food habits compared them with those sympatric Biwa. A total 145 178 were sampled during summer fall 2013. Fish prey, particularly...

This study investigated runoff to clarify the effect of bedrock groundwater dynamics on generation processes in granodiorite headwater catchments (NA and NB) located western Tanzawa Mountains, Central Japan. The rainfall–runoff response water balance calculated using hydrological cycle (HYCY) model with outflow were also analyzed based observed precipitation, runoff, level (at a depth 50 m). In 2013, annual rate was 398 mm (21% rainfall) NA 1209 (63% NB, respectively. varied for...

礫河原の再生には,植物生態学,動物生態学,河川生態学,地形学,水文学,土木工学,人文社会学などのさまざまな学術領域が関連している。本報告では,礫河原再生に関してとりあつかう対象の測定間隔や解析範囲のほか,対象とする現象が影響する空間的な広がりやその発生頻度や時系列変化など,時間的・空間的スケールの整理を行った。とくに,礫河原を生態系ネットワークのインターフェースと位置づけ,礫河原が介在する諸現象の関連を検討した。既往の知見をスケールの枠組みで取りまとめることが,礫河原再生への統合的な枠組みや,段階的な目標設定を行える枠組み構築を進める一助となると考えられた。

Abstract When forest disturbance impacts adjacent headwater streams, the recovery of habitat conditions and populations can take over several decades. Thus, considering long‐term, historical legacies disturbances is key for understanding managing forest–stream linkages. We focused on small‐scale such as small‐block harvesting landslides. compared long‐term (past 100 years) cumulative effects between anthropogenic natural stream abundance a specialist, Scopura montana (Plecoptera:...

Forest-stream ecotones possess prominent detritus-based food webs, and 137Cs-contaminated litter can influence the contamination levels of animals inhabiting such ecosystems. The effects leaching on contaminated induce greater absolute differences between 137Cs concentrations forest stream in more sites. Because be attenuated temporally, spatiotemporal patterns may vary depending both amount deposition passage time. To test this hypothesis, we sampled coniferous needle broad-leaved deciduous...

Abstract Humans have altered river flows leading to a loss of connection with floodplain habitats. The expansion agriculture in floodplains has resulted landscapes dominated by irrigated farmland. A key challenge water management is conserve existing ecological communities and habitat heterogeneity, while simultaneously maintaining engineered infrastructure for agriculture. In this study, we focused on an artificial channel network irrigation regulated flow regime its function as various...

これまでの小渓流や農業水路といった小さな流れにおける水生生物の研究から, 水文学との関連や, 流域スケールへの展開について述べた.

Although the program for water environment improvement has been practiced since 1990s maintaining multifunctionality of agricultural watercourses such as providing amenity, declining waterfront play remains one major concern. From this aspect, we investigated environmental characteristics irrigation canals ensuring children's play. First, actual activities and locations were described using workshop survey, second, used by children examined survey physical, chemical, biological structural...

湧水起源の都市小河川において，希少魚種であるホトケドジョウLefua echigoniaを対象とする網羅的な生息環境調査を実施し，得られたデータから生息環境評価モデルを構築した．月一回の頻度で2年間実施した現地調査の結果に対してランダムフォレスト（RF）を適用した．その結果，高い再現性が得られたとともに，本種の生息環境として，流速が重要であることが示唆された．生息場ポテンシャルを示す応答曲線により，20 cm/s以下の低流速域に加え，50 cm/sを超える条件において生息場ポテンシャルが高く評価された．これは，既往の研究における報告と相反するが，対象水域には多くの大礫や植生が存在していることから，これらによる流速緩和効果が本種の分布に寄与したと考えられる．今後は，遊泳能力の定量評価等による本種の生息環境特性の理解深化が課題である．