Projecting future habitat quality of three midwestern reservoir fishes under warming conditions     

Richard R. Budnik  Joseph D. Conroy  Richard D. Zweifel  Stuart A. Ludsin  Elizabeth A. Marschall 《Ecology of Freshwater Fish》2021,30(1):31-47

Rising temperatures caused by climate change are likely to affect cool‐water and warm‐water fishes differently. Yet, forecasts of anticipated temperature effects on fishes of different thermal guilds are lacking, especially in freshwater ecosystems. Towards this end, we used spatially explicit, growth rate potential (GRP) models to project changes in seasonal habitat quality for a warm‐water piscivore (largemouth bass Micropterus salmoides), a cool‐water piscivore (walleye Sander vitreus) and a hybrid piscivore (saugeye S. vitreus × S. canadensis) in two Midwestern reservoirs. We assessed habitat quality for two periods (early and middle 21st century) under two realistic greenhouse gas emission scenarios (a mid‐century emissions peak and a rapid continuous increase in emissions). Largemouth bass were projected to experience enhanced or slightly reduced habitat during all seasons, and throughout the mid‐21st century. By contrast, walleye habitat was projected to decline with anticipated warming, except during the spring in the smaller of our two study reservoirs and during the fall in the larger of our two study reservoirs. Saugeye habitat was projected to either increase modestly or decline slightly during the spring and fall and declines in habitat quality and quantity that were smaller than those for walleye were identified during summer. Collectively, our findings indicate that climate warming will differentially alter habitat suitability for reservoir piscivores, favouring warm‐water species over cool‐water species. We expect these changes in habitat quality to impact the dynamics of reservoir fish populations to varying degrees necessitating the consideration of climate when making future management decisions.  相似文献   

Case study on an integrated operation planning of multiple reservoirs for irrigation in Japan     

Hirofumi Kakudo  Yutaro Senga 《Irrigation and Drainage Systems》1991,5(2):115-128

In spite of several attempts at integrated operation planning, multiple reservoirs in Japan have been operated by trial and error without any formal rules. Subjects of integrated operation are not only showing optimal usage of daily storage levels as an operational policy but also providing a countermeasure for droughts.Objectives of this study are to make a formal operation rule of multiple reservoirs for irrigation using the theory of Required Storage for Drought Curve (RSDC) Method and to propose operational policy for multiple reservoirs as large water supply systems. The Iwaki river basin, on which there are four reservoirs for irrigation parallel with each other, is considered to be a model river basin with a large water system for this case study.From results of simulations using historical data, comparing an individual operation rule with an integrated operation rule on several indices, effectiveness of the latter rule is recognized. Under integrated operation, water losses are minimized and excessive water conservation can be avoided over the whole area to benefit while target river discharge is maintained at key control points because water usage from all reservoirs is well balanced in relation to water availability.  相似文献   

汕头市中小水库库区水源林调查研究初报   总被引：2，自引：0，他引：2  

谢少鸿  陈远合  肖泽鑫  蔡乙辉  郑道序 《防护林科技》2004,(5):9-11

以汕头市的中小水库库区水源涵养林林分为研究对象 ,通过调查几个比较有代表性的水库库区的植物情况、土壤主要理化状况 ,从而探讨不同森林群落植物多样性与涵养水源功能的关系 ,为进一步确定不同立地、不同类型林分的改造树种和造林模式提供科学依据  相似文献   

Use of geographical information systems as a tool for predicting fish yield in tropical reservoirs: case study on Sri Lankan reservoirs     

S. S. De Silva  U. S. Amarasinghe  & C. Nissanka  W. A. D. D. Wijesooriya  & M. J. J. Fernando 《Fisheries Management and Ecology》2001,8(1):47-60

Use of geographical information systems (GIS) in inland fisheries has hitherto been essentially restricted to site evaluation for aquaculture development and assessment of limnological changes in time and space in individual water bodies. The present GIS study was conducted on the land-use pattern of the catchments of nine reservoirs in Sri Lanka, for which detailed fishery data, viz. yield, fishing intensity, landing size of major constituent species, together with selected limnological data such as conductivity and chlorophyll- a , were available. Potential statistical relationships (linear, curvilinear, exponential and second-order polynomial) of fish yield ( FY , in kg ha⁻¹ yr⁻¹) to different land-use patterns, such as forest cover ( FC , in km²) and shrub-land ( SL , in km²), either singly, or in combination, and/or the ratio of each land type to reservoir area ( RA in km²) and reservoir capacity ( RC in km³), were explored. Highly significant relationships were evident between FY to the ratio of SL and/or FC + SL to RA and/or RC . Similarly, the above land-use types to RA and RC ratios were significantly related to limnological features of the reservoirs. The relationships of FY to various parameters obtained in this study were much better correlated than those relationships of FY to limnological and biological parameters used in yield prediction in tropical and temperate lacustrine waters previously.  相似文献   

Putative human and avian risk factors for avian influenza virus infections in backyard poultry in Egypt     

Basma M. Sheta  Trevon L. Fuller  Brenda Larison  Kevin Y. Njabo  Ahmed Samy Ahmed  Ryan Harrigan  Anthony Chasar  Soad Abdel Aziz  Abdel-Aziz A. Khidr  Mohamed M. Elbokl  Lotfy Z. Habbak  Thomas B. Smith 《Veterinary microbiology》2014

Highly pathogenic influenza A virus subtype H5N1 causes significant poultry mortality in the six countries where it is endemic and can also infect humans. Egypt has reported the third highest number of poultry outbreaks (n = 1084) globally. The objective of this cross-sectional study was to identify putative risk factors for H5N1 infections in backyard poultry in 16 villages in Damietta, El Gharbia, Fayoum, and Menofia governorates from 2010–2012. Cloacal and tracheal swabs and serum samples from domestic (n = 1242) and wild birds (n = 807) were tested for H5N1 via RT-PCR and hemagglutination inhibition, respectively. We measured poultry rearing practices with questionnaires (n = 306 households) and contact rates among domestic and wild bird species with scan sampling. Domestic birds (chickens, ducks, and geese, n = 51) in three governorates tested positive for H5N1 by PCR or serology. A regression model identified a significant correlation between H5N1 in poultry and the practice of disposing of dead poultry and poultry feces in the garbage (F = 15.7, p < 0.0001). In addition, contact between domestic and wild birds was more frequent in villages where we detected H5N1 in backyard flocks (F = 29.5, p < 0.0001).  相似文献   

Detection of anti-Leishmania infantum antibodies in sylvatic lagomorphs from an epidemic area of Madrid using the indirect immunofluorescence antibody test     

Inmaculada Moreno  Julio Álvarez  Nerea García  Santiago de la Fuente  Irene Martínez  Eloy Marino  Alfredo Toraño  Joaquin Goyache  Felipe Vilas  Lucas Domínguez  Mercedes Domínguez 《Veterinary parasitology》2014,199(3-4):264-267

An outbreak of human leishmaniosis was confirmed in the southwest of the province of Madrid, Spain, between July 2009 and December 2012. Incidence of Leishmania infection in dogs was unchanged in this period, prompting a search for alternative sylvatic infection reservoirs. We evaluated exposure to Leishmania in serum samples from animals in the area with an indirect immunofluorescence test (IFAT). Using promastigotes from six culture passages and a 1/25 threshold titer, we found anti-Leishmania infantum seroreactivity in 9.3% of cats (4 of 43), 45.7% of rabbits (16/35) and 74.1% of hares (63/85). Use of promastigotes from >10 in vitro passages resulted in a notably IFAT lower titer, suggesting antigenic changes during extended culture. Postmortem inspection of seropositive animals showed no clinical signs of infection. The results clearly suggest that asymptomatic hares were the main reservoir in the outbreak, and corroborate IFAT as a sensitive serological surveillance method to detect such cryptic Leishmania infections.  相似文献   

Destratification in deep fish culture reservoirs in Israel: Practice and modelling     

Ana Milstein  Myron Zoran  Hans Juergen Krambeck 《Aquaculture International》2001,9(1):3-15

Thermal stratification negatively affects water quality, and thus is a threatto fish culture in deep water ponds and reservoirs. To prevent and controlit, a device based on an underwater propeller that vertically transportsoxygen rich warm water from the epilimnion down to the anoxic and colderhypolimnion was assembled. The empirical results so far obtained in Israelidual purpose reservoirs for field crop irrigation and fish culture aresummarized herein, and a mathematical model of the device's effect onreservoir thermal structure is presented.  相似文献   

天津市3座水库大型底栖动物群落结构及其与环境因子的关系(英文)     

姜巨峰  傅志茹  李文雯  张韦  孟一耕  钱红 《农业科学与技术》2014,(6):947-953

[目的]研究天津市3座水库大型底栖动物群落结构及其与环境因子的关系。[方法]2011年5月、7月、9月分别对天津市于桥水库、北大港水库、尔王庄水库的14个采样点的大型底栖动物进行调查,分析各水库大型底栖动物物种多样性状况,并评价各水库的水质情况。[结果]所有采样点共采集到大型底栖动物22种,其中水生昆虫6种,软体动物7种,甲壳类2种,寡毛类7种。于桥水库5月、7月、9月大型底栖动物的种类分别为11种、8种、10种,大型底栖动物的平均密度和平均生物量分别为132.43 ind./m2、50.09 g/m2;采用Margalef物种丰富度指数d值、Shannon多样性指数(H)和Pielou均匀度指数综合评价,于桥水库为轻-中度污染。北大港水库5月、7月、9月种类分别为5种、5种、5种。大型底栖动物的平均密度和平均生物量分别为218ind./m2、2.70 g/m2;采用物种丰富度指数d值、Shannon多样性指数H值和均匀度指数综合评价,北大港水库为重度污染。尔王庄水库5月、7月、9月大型底栖动物的种类分别为3种、5种、5种。大型底栖动物的平均密度和平均生物量分别为104 ind./m2、0.20 g/m2;采用物种丰富度指数d值、Shannon多样性指数H值和均匀度指数综合评价,结果表明尔王庄水库为中度污染。[结论]三座水库均受到了富营养化污染,污染程度为:北大港水库尔王庄水库于桥水库。  相似文献   

三峡库区30 a间土地利用景观特征的粒度效应   总被引：5，自引：3，他引：2  

曹银贵  周伟  王静  袁春 《农业工程学报》2010,26(6):315-321

该研究是为了测度景观指数在时空上随粒度变化的特征;总结相同景观在不同粒度下的景观特征差异。利用不同的粒度大小,将景观类型图进行了栅格化,并选取景观指数,在类型与整体景观的水平上,进行了景观指数的粒度效应测度。并采用相关性分析的方法,分析了各景观指数与粒度相关性的差异。研究表明：粒度效应能有力地论证三峡库区近30 a景观格局变化的特征;不同的景观指数随粒度也表现出不同的敏感程度,较敏感的是斑块密度、有效网格大小、正归化形状指数、聚合指数。同一类型景观在不同的景观指数测度上表现不同的变化规律,随粒度变化较为敏感的是耕地（坡度＜25°）、林地、草地和城镇建设用地;多数指数呈现出随粒度变化的拐点,尤其在尺度400 m;整体水平上,斑块密度和景观形状指数受粒度变化的影响较大;同一指标与粒度的相关性在类型水平和时间跨度上大多呈现出较高的一致性。此次研究很好反映了景观格局指数在不同空间分辨率（粒度）上的变化规律。  相似文献   

平原水库利用排渗减压技术预防库外农田浸没     

徐瑞兰  曹先玉  杨国瑞  高开绪 《山东农业大学学报(自然科学版)》2007,38(3):432-436

由于黄泛区平原水库坝基一般为软弱透水地基,坝基经过防渗处理后,坝基渗透稳定,渗漏量得到有效控制,但坝基不可避免的还有一定数量的渗漏量,下游坝址外尚保留一定的剩余水头,渗水如果不及时排走,会导致区域地下水位升高,造成库外农田浸没。笔者以山东聊城发电厂新厂引黄调蓄水库为依托,阐述平原水库如何用排渗沟和减压井联合排渗减压技术防止库外浸没和土地盐碱化。减压井和排渗沟联合排渗减压是降低地下水位、防止库外浸没的有效措施。  相似文献