李杏混栽园食心虫种类及其种群动态调查

以辽宁省果树科学研究所李杏资源圃为研究对象,利用4种食心虫的性诱剂,诱捕调查圃内食心虫发生种类及其种群消长动态。结果表明,李杏资源圃食心虫发生种类有梨小食心虫、李小食心虫、桃小食心虫和桃蛀螟4种,优势种群为梨小食心虫和李小食心虫。梨小食心虫后期蛾量高峰与低谷难以准确界定,世代重叠现象严重;李小食心虫一年有3个发生高峰期;桃小食心虫一年有2个发生高峰期。桃蛀螟全年只诱到3头成虫,可以忽略不计。     

南漪湖银鱼资源衰退原因及对策

南漪湖具有银鱼生长繁衍的良好生态条件,１９８１～１９８７年总产银鱼１１５０ｔ。１９８８年后由于过度捕捞,经济鱼类种类组成改变;加上多年旱灾低水位的影响,造成资源严重衰退。通过分析认为：合理调整经济鱼类种类组成,开展放流移植增殖,加强资源保护管理等将使银鱼年产量达到历史最高水平的２．６９倍。     

园林树木衰退原因及其保健措施

对安徽主要城市园林树木生长衰退与环境条件的关系进行了调查,结果表明:引起园林树木衰退的主要原因有土壤透气性能差,土壤污染,土壤质地不良,根系深埋或根系裸露,机械伤害,病虫危害,树龄过大,空气污染等;提出了园林树木的保健措施。     

安徽农业大学实验林场湿地松枯死原因的分析

对安徽农业大学实验林场湿地松枯死原因的调查研究结果表明,造成树木枯死的原因是多方面因素共同作用的结果,是一种林木衰退病。其衰退枯死的原因为:①诱发因素:温度年较差较大,降雨量分布不均匀,土壤粘重板结,管理不善;②激化因素:干旱,雨季积水;③促进因素:松枯梢病菌、根腐病菌、立木腐朽病菌,天牛、小蠹虫等次生性病虫害的危害。     

认识和重视-类病害——森林衰退病

本文就“森林衰退病”(Forest decline)理论的概念、意义,森林衰退病病原,“衰退病”(Decline,Dicline disease)模式,以及诱发因素(Predisposing factors)、激化因素(Inciting factors)和促进因素(Contributing factors)之间的相互关系作了综述介绍,并看重强调了运用这一新的植物病理学理论,认识和指导我国林业及热作生产的重要现实意义。     

Rarity and decline in bumblebees - A test of causes and correlates in the Irish fauna

Bees are believed to be in decline across many of the world’s ecosystems. Recent studies on British bumblebees proposed alternative theories to explain declines. One study suggested that greater dietary specialization among the rarer bumblebee species makes them more susceptible to decline. A second study disputed this theory and found that declines in British bumblebees were correlated with the size of species’ European ranges, leading to the suggestion that climate and habitat specialization may be better indicators of the risk of decline. Here we use a new and independent dataset based on Irish bumblebees to test the generality of these theories. We found that most of the same bumblebee species are declining across the British Isles, but that, within Ireland, a simple food-plant specialization model is inadequate to explain these declines. Furthermore, we found no evidence of a relationship between declines in Irish bumblebees and the size of species’ European ranges. However, we demonstrate that the late emerging species have declined in Ireland (and in Britain), and that these species show a statistically significant westward shift to the extremity of their range, probably as a result of changing land use. Irish data support the finding that rare and declining bumblebees are later nesting species, associated with open grassy habitats. We suggest that the widespread replacement of hay with silage in the agricultural landscape, which results in earlier and more frequent mowing and a reduction in late summer wildflowers, has played a major role in bumblebee declines.     

黑龙江省东部山区谷地云冷杉林衰退与其生境条件的相关性

对黑龙江省伊春林区的凉水国家级自然保护区的云冷杉林进行了调查。根据pH值、阳离子代换量、营养元素、微生物数量及云杉根部着生小斑块的大小等,分析了黑龙江省东部山区谷地云冷杉林的衰退原因。结果表明:土壤pH值与云杉死亡没有明显关系;土壤阳离子代换量低是云杉死亡的一个因素;云杉衰退与营养元素的吸收及微生物数量无明显关系;云杉的生长与根部着生小斑块的大小存在密切的相关关系,斑块越大,云杉长势越好,生存周期也更长。     

六冲河鱼类资源衰退的原因与对策建议

乌江上游主要干流六冲河多年来由于修建水利工程、人为过度捕捞、引进外来鱼种、水域污染、法律监督管理不力,导致该河中的野生优质鱼类趋于低龄化、小型化、低质化,资源量急剧下降,部分名优鱼类濒临灭绝的严峻形势.从加强领导、修建水利工程时应保护鱼类的生存,加快地方特有鱼类驯化养殖,实现人工放流进行资源修复,加强渔政管理等方面来实现对六冲河鱼类资源的保护.     

石灰氮颗粒剂防治番茄根结线虫

用石灰氮颗粒剂(有效成分为氰胺化钙)进行了处理温室土壤防治番茄根结线虫试验。试验结果表明,石灰氮颗粒剂可较好地控制番茄根结线虫为害。石灰氮3.3,5.0,6.7kg/667m23个处理,药后90天土壤中2龄幼虫数量减退率分别为16.85%,31.58%和61.54%,而对照药剂1.8%阿维菌素乳油1.0L/667m2处理的线虫减退率为37.28%。药后90天石灰氮颗粒剂各处理防治效果分别为60.00%,66.00%和73.72%,而对照药剂为61.99%。石灰氮颗粒剂可有效地控制番茄根结线虫的为害,有较高的推广应用价值。     

四川省宜宾市茶园非水溶性农药帕力特药效研究

[目的]评价非水溶性农药帕力特的药效。[方法]通过在四川省宜宾市2个不同地理区域的茶园小区中施用帕力特和对照药剂吡虫啉,比较了不同杀虫剂对假眼小绿叶蝉的田间药效。[结果]药后21 d内,在江安县和宜宾县均未见茶树出现生理毒害现象,且药后假眼小绿叶蝉数量急剧减少;宜宾县最佳防效达95.75%、最高虫口减退率达97.73%,显著好于对照药剂吡虫啉;江安县最佳防效达77.72%,最高虫口减退率达78.50%。[结论]使用非水溶性农药帕力特起到明显的药效作用,也提高了茶叶饮用安全,具有较强的市场推广潜力。