Freshwater mussel assemblage structure in a regulated river in the Lower Mississippi River Alluvial Basin,USA

• 1. This paper documents a diverse, reproducing freshwater mussel community (20 species) in Lower Lake — an impounded, regulated portion of the Little Tallahatchie River below Sardis Dam in Panola Co., Mississippi, USA.
• 2. Despite being regulated and impounded, the lake has a heterogeneous array of habitats that differ markedly in mussel community attributes. Four distinct habitat types were identified based on current velocity and substrate characteristics, representing a gradient from habitats having lotic characteristics to lentic habitats. All four habitat types supported mussels, but habitats most resembling unimpounded, lotic situations (relatively higher current velocity and coarser substrate) had the highest mussel abundance and species density (10.1 mussels m^?2, 1.8 species m^?2, respectively). Lentic habitats (no flow, fine substrate) were characterized by lower abundance and species density (2.0 mussels m^?2, 0.8 species m^?2, respectively), but supported mussel assemblages distinctive from lotic habitats.
• 3. Evidence of strong recent recruitment was observed for most species in the lake and was observed in all four habitat types.
• 4. Although impounded and regulated, Lower Lake represents one of the few areas of stable large‐stream habitat in the region. The presence of a diverse, healthy mussel community in this highly modified habitat suggests that a large component of the regional mussel fauna is relatively resilient and adaptable and is limited primarily by the absence of stable river reaches. Management actions that increase stream stability are likely to result in expansion of the mussel fauna and restoration of a valuable component of ecosystem function in this region.

Published in 2006 by John Wiley & Sons, Ltd.     

广州龙洞水库红锥林下药用植物资源调查

通过实地调查与植物鉴定,对广州市龙洞水库红锥（Castanopsis hystrix）人工林林下药用植物 资源进行统计分析。结果表明水库红锥人工林工区共有林下药用植物 102 种,隶属 52 科 86 属;其中林 下蕨类药用植物 7 科 7 属 7 种,林下双子叶药用植物 38 科 69 属 85 种,单子叶林下药用植物 7 科 10 属 10 种。建议选择适宜的人工林地,以耕代抚发展林下药用植物栽培;同时合理开发利用野生林下药用植 物资源,严禁掠夺式采摘;并且鼓励当地主管部门、经营主体或社会组织加大对周边群众及游客的宣传 教育,提高人们的环保意识,增强其可持续发展概念。     

三峡库区坡地梨-旱稻农业模式生态经济分析

运用生态经济学原理对三峡库区坡地新建梨-旱稻复合系统的生态效益和经济效益进行了研究。结果表明:与清耕梨园相比,梨园间作旱稻并秸秆还田后,有良好的水土保持作用和改土培肥效果,同时能有效控制田间杂草,减少梨园病虫害的发生,消减非点源N污染负荷60.19 kg/hm2,非点源P污染负荷8.0kg/hm2。与单一系统相比,复合系统提高土地利用率44%,能量经济系数上升2%。研究结果表明:梨-旱稻复合系统是一种具有良好生态效益的高效种植模式,值得在库区大力推广。     

绵枣儿用于三峡库区植被重建及组织培养快繁研究

绵枣儿的淹水试验及组织培养结果表明:绵枣儿的成活率高、长势较好,适于库区植被重建;假鳞茎诱导愈伤组织较快,最佳培养基为6-BA 2.0 mg/L+NAA 0.3 mg/L;不定芽分化最适培养基为MS+6-BA 2.0 mg/L+NAA 0.3 mg/L。     

水位变化对蛤蟆通水库浮游植物种群动态影响的研究

1991－1993年蛤蟆通水库水位变化对浮游植物种群的动态影响研究结果表明：1）浮游植种属数随水位下降而减少；2）浮游植物生物量随水位下降而升高，其关系式为y＝299．46－3．37x,r=-0.998;3)浮游植物多样性指数随水位降低而变小，并且与水位呈明显的相关性（r＝0．999，r＝0．983）。     

Trophic relationships and ecosystem characteristics in a newly-impounded man-made lake in Thailand

Abstract  The trophic dynamics of a newly-impounded south east Asian reservoir, Pasak Jolasid, Thailand, monitored from its creation, were constructed using ecopath , a mass-balanced model. The trophic levels (TLs) of 36 ecological groups varied between 1.0 and 3.2. The majority of fish biomass was at the second TL, where the fishery is concentrated. Some food resources (benthic organisms and zooplankton) were not fully used, whereas phytoplankton and benthic algae were important components of the food web, which is based on phytoplankton and detritus. The implications of these findings are discussed in terms of ecological maturity of the ecosystem and possible fishery management of this multi-purpose reservoir.     

三峡库区重庆开县段阳台蔬菜产业发展初探

对三峡库区开县段蔬菜的产业背景及阳台蔬菜产业发展的优势进行了分析,剖析了开县阳台蔬菜适宜产业发展的主要种类,提出了开县段阳台蔬菜发展思路及对策,为三峡库区整体转型发展、城镇化建设和民生问题解决提供了一个新思路。     

浅谈牡丹江市天长山水库除险加固的必要性

目前,我国许多水库仍存在着施工技术落后、防洪标准偏低,而且达不到相关规范要求,工程老化等情况;这样就形成了大量的病险水库,其危害严重地威胁着下游人民的生命及财产安全。因此笔者就牡丹江市天长山水库病险的基本情况,阐明了除险加固的必要性。     

对宁夏固原市做好水库防洪蓄水调度的对策及建议

实现控制洪水向洪水管理转变,从综合的角度考虑洪水,它不仅是灾害,在一定条件下也可能变成资源;从风险的角度去考虑洪水,它是有风险,在降低或转移同时会带来可观的收益。     

百倍冲水库种草养鱼防淤试验初报

百倍冲水库自1976年修建以来,养鱼由于饲料长期缺乏,300亩养鱼水面常年产鲜鱼1000kg左右,库内每年淤积泥砂0.6～0.8万立方米。作者于1985～1987年在库内的消落区种植黑麦草,紫云英;荒山种象草、扁穗牛鞭草;堤坝上种岸杂一号狗牙根;幼林地种鸡脚草、拉丁鲁白三叶等牧草配套养鱼和防止水土流失进行试验研究。结果,库内年鲜鱼产量由种草前1000kg提高到7000～8000kg,泥砂淤积量每年减少0.516万立方米,经济生态效益显著。