Lateral and longitudinal flight dispersals of a stonefly,Alloperla ishikariana (Plecoptera,Chloroperlidae), from the hyporheic zone in a gravel-bed river in Japan     

《Limnologica》2021

The life-history traits of amphibitic insects are not well understood. These insects inhabit saturated interstitial areas below the riverbed (hyporheic zone) at the larval stage, mate in terrestrial habitats, and return to rivers for oviposition, but there is no knowledge concerning their dispersal characteristics. We sought to address this by examining how far amphibitic insects disperse away from the channel (laterally) and along upstream or downstream (longitudinally) in a gravel-bed river. Alloperla ishikariana was selected as the focal species because it numerically dominates other amphibites in an 18-km study segment of a 4th-order gravel-bed river in Hokkaido, Northern Japan. Malaise traps were set at various distances from the channel towards the riparian forest to estimate lateral dispersal distances. An elevated stable nitrogen isotope ratio in downstream larvae, caused by the influence of effluent from a wastewater treatment plant, was used to assess longitudinal dispersal by identifying and tracking adult movements. Laterally, 50th and 90th percentile dispersal distances were 11.66 and 35.09 m for female A. ishikariana and 20.59 and 59.20 m for male, respectively; this overlapped with distances previously estimated for other aquatic benthic taxa. Longitudinally, 50th and 90th percentile dispersal distances were 0.74 and 1.43 km for female and 3.11 and 7.87 km for male, respectively. Alloperla ishikariana had one of the longest upstream traveling distances compared with other aquatic insects, and the longest among Plecoptera taxa known thus far where male exhibited a greater dispersal distance. A higher number of adults demonstrated upstream movement, suggesting an upstream bias in the longitudinal dispersal of A. ishikariana. Overall, amphibitic stoneflies did not exhibit distinct dispersal characteristics compared with the results of previous reports on presumably benthic taxa. Our findings support an improved visualization of a multi-dimensionally connected river ecosystem in terms of material flow, including vertical connectivity.  相似文献   

Life history and ecology of the Maghrebian endemic Choroterpes atlas Soldán & Thomas, 1983 (Ephemeroptera: Leptophlebiidae)     

《Limnologica》2021

Knowledge of the basic life history traits of an aquatic organism such as voltinism and growth patterns is a fundamental step in understanding its potential use as indicator taxon and how it adapts to its complex environment. The distribution and life cycle of the Maghrebian endemic Choroterpes atlas Soldán & Thomas, 1983 was studied over a two year period. Random forest classification indicated that the species occupied both permanent and intermittent streams with high water depth, large river bed width and strong water flow. Density-based clustering of body measurements allowed the identification of last-instar nymphs which exhibited a significant sexual dimorphism: F-0 females were significantly larger than corresponding males. In addition, size-frequency plots and generalized additive models indicated that C. atlas exhibited a multivoltine annual cycle with three overlapping generations. Nymphal growth of the first generation happened in winter and spring with emergence occurring in June/July. The second generation grew from June/July to September whereas the third generation was completed from August/September to November. GAMs also indicated that body size varied significantly between years. The large regional distribution, habitat requirement, and phenology of C. atlas may ideally complement the potential use of Ecdyonurus rothschildi as a useful environmental indicator for North African streams and rivers.  相似文献   

Collembola diversity in changing agricultural landscapes of the Thar Desert: A case study in Sriganganagar district of Rajasthan, India   总被引：1，自引：0，他引：1  

M. Faisal  M. Ahmad 《Journal of Arid Environments》2005,63(4):717-724

Seven species of Collembola were recorded from the Thar Desert in India for the first time. Their existence and establishment has been attributed to the change in land use pattern of Sriganganagar district due to the development of canal irrigation. Sampling was done at two distant localities, in which one has been under irrigated agricultural activities since 60–70 years, while at the second locality, such activities began 20 years back. Two species, Xenylla obscura and Isotomodes dagamae, dominated the collembolan communities at all sites. The samples from first locality were rich both in number of individuals as well as species. The sites were hierarchically clustered into a dendrogram to present an analytical picture of community development of collembolan species against the time-scale of succession. Attention was sought to study the insect fauna and their activities in relation to the ongoing greening the desert program.  相似文献   

Macroinvertebrate diversity in fragmented Alpine streams: implications for freshwater conservation     

Michael T. Monaghan  Christopher T. Robinson  Piet Spaak  James V. Ward 《Aquatic Sciences - Research Across Boundaries》2005,67(4):454-464

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应用卫星多角度遥感识别被老鼠和昆虫破坏的草地(英文)   总被引：1，自引：0，他引：1  

罗秀陵  周和生  薛勤  张长虹  汪志刚  周俗 《遥感学报》1997,(Z1)

该文研究用ＡＶＨＲＲ数据监测Ｒｕｏｒｇａｉ县大草原被老鼠、昆虫破坏的情况。鼠虫危害区的光谱特征是：ＡＶＨＲＲ数据的可见光波段（０．５８－０．６８μｍ）地面反射率（ＣＨ１）较高，近红外波段（０．７２５－１．１μｍ）的地面反射率（ＣＨ２）较低，红外辐射波段（３．５５－３．９３μｍ）的亮度温度（ＣＨ３）较高；鼠虫危害区的遥感信息特征在雨季７月最为明显；可用比值植被指数ＲＶＩ（ＣＨ２／ＣＨ１）确定鼠虫危害程度；用多角度获得的ＲＶＩ可反映鼠虫危害。结果显示在这方面上，多角度遥感比多波段光谱法能更好地识别老鼠、昆虫破坏的地区。  相似文献   

The Use of Fossil Caddisfly Assemblages in the Reconstruction of Flow Environments from Floodplain Paleochannels of the River Trent, England     

M. T. Greenwood  P. J. Wood  W. A. Monk 《Journal of Paleolimnology》2006,35(4):747-761

This paper examines the use of fossil larval trichopteran communities to investigate and describe the flow environment of a paleochannel network in the middle reaches of the River Trent floodplain (UK). Previous research utilising fossil insect communities (principally O. Coleoptera, O. Chironomidae) has focussed upon climate reconstruction. However, larval trichopteran communities (O. Trichoptera) also offer an aquatic signal, giving information regarding channel habitat structure and flow environments. The taxonomic diversity of each fossil community and the categorisation of each taxon into a known flow group, using the “LIFE” methodology, facilitates the reconstruction of the river flow conditions at each site based upon known faunal associations with mean flow velocity. A total of 49 trichopteran taxa were recorded from 17 paleochannels (n = 170 samples). Detrended Correspondence Analysis (DCA) identified a environmental gradient on the first DCA axis that reflected variability in flow, from rapid/fast flow to slow flowing and standing water habitats. In addition, two distinct faunal groups were identified on the second DCA axis characteristic of (i) small nutrient rich lentic habitats; and (ii) larger water bodies displaying features of both lentic, lotic and ephemeral habitats where marginal vegetation is abundant on a mineral substratum. The results demonstrate that larval Trichoptera can be used in paleolimnological research to reconstruct a flow signal and provide additional information regarding the aquatic habitat structure. Their wider use in describing the aquatic environment, in association with other proxies (e.g., Chironomidae and Coleoptera), may provide a more holistic understanding of floodplain paleoenvironment succession.  相似文献   

Sciaridae in lake sediments: indicators of catchment and stream contribution to fossil insect assemblages     

Oliver Heiri  André F. Lotter 《Journal of Paleolimnology》2007,38(2):183-189

The larval head capsules of Sciaridae (black fungus gnats) are transported into lakes from terrestrial habitats, in most cases via streams or rivers, and preserve well in lake sediments. The abundance of sciarid remains can provide information on the importance of terrestrial and running-water input into fossil insect assemblages in lake sediments if examined in relation to the number of fossils of aquatic insects such as the Chironomidae, Thaumaleidae, Ceratopogonidae, or Simuliidae. Here we describe fossil head capsules of sciarid larvae and provide an example of how these remains can be used to constrain past changes in taphonomic processes that influence fossil chironomid records.  相似文献   

AMS 14C dating of tundra lake sediments using chironomid head capsules     

Marie-Andrée Fallu  Reinhard Pienitz  Ian R. Walker  Jonathan Overpeck 《Journal of Paleolimnology》2004,31(1):11-22

Radiocarbon dating of late-Quaternary sediments from high-latitude lakes is often complicated by the influx of old carbon, reservoir effects, or both. If terrestrial plant macrofossils are also absent, the dating of bulk sediment often provides the only means to establish chronologies for these problematic sediment sequences. Given that chironomid (non-biting midge) remains are sufficiently abundant in many northern lakes to be ¹⁴C-dated via the accelerator mass spectrometry (AMS) method, we decided to explore their utility in age-model development. Five age determinations based on chironomid material were obtained from a lake sediment core sampled in the shrub tundra of northern Québec. These results were compared to six AMS bulk sediment ages, as well as to a date obtained from Drepanocladus spp. The chironomids yielded consistently younger ages (with increasing age offset upcore), confirming both the presence of a reservoir effect and the value of chironomids in establishing more reliable ¹⁴C chronologies.  相似文献   

The earliest amber-recorded type cockroach family was aposematic (Blattaria: Blattidae)     

《Cretaceous Research》2017

Only seven adult cockroaches have been described from Mesozoic amber. Balatronis cretacea gen. et sp. nov. from the Cenomanian burmite is the most ancient member of the type cockroach family Blattidae and the only one recorded from Cretaceous strata. Individuals represented by immature and adults (n = 14, 4) constitute 3.2 per cents of all Myanmar amber cockroaches surveyed by us – indicating habits close to source trees supported with bark body pattern (absent in sedimentary fossils). Preservation in small-sized pieces suggests longer post-depositional transportation. Its characteristic aposematic coloration suggests direct ancestry to the living repellent harlequin cockroach Neostylopyga rhombifolia, which lost its wings. Along with the bizarre Manipulatoridae, Eadiidae and Alienopteridae species, it exemplifies the high disparity of cockroaches in the ancient amber–producing tropical forest, but also documents the appearance of advanced modern taxa.  相似文献   

A high‐resolution record of mire development and climatic change spanning the Late‐glacial–Holocene boundary at Church Moss,Davenham (Cheshire,England)     

P. D. M. Hughes  H. K. Kenward  A. R. Hall  F. D. Large 《第四纪科学杂志》2000,15(7):697-724

Excavations of deposits filling a closed basin within glacial drift at Church Moss, Davenham, near Northwich (Cheshire, England) revealed a sequence of Late‐glacial and Early Holocene sediments. Analyses of pollen and plant and invertebrate macrofossils were undertaken, together with loss‐on‐ignition analyses and a programme of AMS radiocarbon dating, to provide a record of changing biostratigraphy and climatic and ecological regimes. The infilling of features identified as frost‐cracks in the till flooring the basin gave remains that reflected conditions of extreme cold towards the end of the Devensian. The pollen record from a 3.5 m sequence of peat towards the deepest part of the basin, supported by radiocarbon dates, shows that organic deposition was initiated during the Late‐glacial Interstadial and continued into the early part of the Holocene. There was some evidence for a cool episode during the interstadial, with amelioration prior to the rapid onset of the tundra conditions of the Loch Lomond Stadial. Following the stadial, amelioration was rapid. There was evidence from both central and marginal sequences for a mosaic of fen dominated by sedges and often also mosses, with short‐lived small pools through much of the succession. Change to terrestrial conditions proceeded intermittently, probably as a result of subsidence caused by solution of underlying salt‐bearing strata. Copyright © 2000 John Wiley & Sons, Ltd.  相似文献