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Population size estimates are an integral part of rare plant conservation, but common abundance measurements such as cover and ramet number may not accurately index genet population size for vegetatively spreading species. Population monitoring of Kincaid’s lupine (threatened species) populations occurs through genet-anonymous leaf cover and raceme counts despite extensive, non-adventitious rhizome growth. While the current monitoring scheme provides important resource abundance measurements for the endangered Fender’s blue butterfly, whose larvae feed on Kincaid’s lupine leaves, the methods are not appropriate for estimating lupine genet number. Major axis regression revealed well supported statistical relationships between cover, raceme, and plantlet (a measurement of modular plant growth) density within six study patches (n = 3 populations) of Kincaid’s lupine (R2 > 0.90) and when all patch data were combined (R2 > 0.91). Genet population size estimates from genotype only data with ACE (an estimator used to infer species richness) were similar to estimates derived from a combination of plantlet density and genet to plantlet ratios (genotype derived) in small, more thoroughly genotyped lupine patches. However, genet number estimates from ACE were 3–5-fold greater in less intensely genotyped patches. Genet-anonymous plant abundance measurements, such as cover, can be used to estimate genet number in populations of vegetatively spreading plants provided they are calibrated with a unit of modular plant growth. Calibration of vegetative measurements, consistency of between population relationships, and closer scrutiny of highly supported statistical models may be necessary to develop more pertinent monitoring methods for rare, vegetatively spreading plants. 相似文献
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陈平 《农业图书情报学刊》2012,24(8):201-205
介绍了气象学的"蝴蝶效应"概念。从"蝴蝶效应"与读者服务机制分析入手,通过对细节服务机理、内容的阐述和细节管理模型的构建,以强化竞争优势,优化系统管理为着力点,并引入危机管理这一服务新理念,从而为进一步提高流通阅览过程中的读者服务水平、消除"蝴蝶效应"的负面影响提供理论依据。 相似文献
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湖南省4个自然保护区蝶类多样性与相似性研究 总被引:1,自引:1,他引:0
对湖南省南岳、壶瓶山、天平山和舜皇山4个自然保护区蝶类资源进行了系统的调查,共鉴定4个自然保护区蝶类398种,分属于11科,169属。利用Jacard的相似性系数计算方法对4个保护区蝶类的区系相似性进行对比,并通过UPGMA聚类运算验证。结果显示南岳和舜皇山两个保护区的相似性系数大于0.6,为中等相似水平;南岳、舜皇山和壶瓶山、天平山4个保护区的相似性系数都在0.4以下,为中等不相似,并分析了原因,给出了4个自然保护区蝶类分布的相似性聚类图。 相似文献
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提出了一种空气罐与超压泄压阀联合设置的停泵水锤防护方案,并基于瞬变流计算的特征线法建立了空气罐、液控蝶阀、超压泄压阀等边界条件的数学模型,模拟了停泵工况下系统的压力变化过程.结合工程实例,对比分析了空气罐单独防护、空气罐与两阶段关闭泵后液控蝶阀联合防护以及空气罐与超压泄压阀联合防护对停泵水锤的影响.在空气罐体型一定时,对超压泄压阀的启闭规律进行了敏感性分析.计算结果表明,空气罐与两阶段关闭泵后液控蝶阀联合防护方案对输水系统正负水锤防护均不利;而空气罐与超压泄压阀联合防护方案对输水系统正负水锤均有较好的防护效果,与空气罐单独防护方案相比,泵后高压管段最高压应力由1.343 MPa降至1.087 MPa,在满足承压标准1.2 MPa的基础上安全裕度提高了9.4%,空气罐体型也由200 m3缩减至160 m3.超压泄压阀应在5 s内开启至全开度,且开启后持续时间应接近1个相长. 相似文献
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两年三项田间试验的结果表明,应用Bt制剂(HD-1)防治菜青虫具有良好防治效果,而且虫龄越大,防效越高,尤其防治4~5龄幼虫的校正死亡率可达90%至100%。 相似文献
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Annie J Krueger Kathryn Hanford Thomas J Weissling Ana M Vlez Troy D Anderson 《Journal of insect science (Online)》2021,21(2)
Insecticide exposure has been identified as a contributing stressor to the decline in the North American monarch butterfly Danaus plexippus L. (Lepidoptera: Nymphalidae) population. Monarch toxicity data are currently limited and available data focuses on lethal endpoints. This study examined the 72-h toxicity of two pyrethroid insecticides, bifenthrin and β-cyfluthrin, and their effects on growth and diet consumption. The toxicity of bifenthrin to caterpillars was lower than β-cyfluthrin after 72 h. Survival was the most sensitive endpoint for bifenthrin, but diet consumption and caterpillar growth were significantly reduced at sublethal levels of β-cyfluthrin. Using AgDRIFT spray drift assessment, the aerial application of bifenthrin or β-cyfluthrin is predicted to pose the greatest risk to fifth-instar caterpillars, with lethal insecticide deposition up to 28 m for bifenthrin and up to 23 m for β-cyfluthrin from treated edges of fields. Low boom ground applications are predicted to reduce distances of lethal insecticide exposure to 2 m from the treated field edge for bifenthrin and β-cyfluthrin. Growth and survival of fifth-instar monarch caterpillars developing within the margins of a treated field may be significantly impacted following foliar applications of bifenthrin or β-cyfluthrin. These findings provide evidence that pyrethroid insecticides commonly used for soybean pest control are a potential risk to monarch caterpillars in agricultural landscapes. 相似文献
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