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We explore two methods that correct for differential sampling effort when estimating the true number of species in a region based on samples such as those typically recorded in museum or conservation databases. The two methods are: (1) a phenomenological model that relies on a saturating sampling curve; and (2) a model based on a lognormal distribution of species abundances. We test these methods using a database for the butterflies of Oregon and find that the distribution of high-diversity areas, using the estimated, or “asymptotic”, diversities, is strikingly different from the geographic pattern one would deduce if the raw data were used, without correcting for differential sampling effort. Further, we show that differences in accuracy exist between the two estimation procedures, and that these differences are aggravated at small sample sizes; we argue that estimates based on the lognormal distribution should be preferred because they can offer substantial improvement over analyses based solely on the raw data, generally without risking overestimation. Lastly, using both the database and estimated values of butterfly diversity, we show that the distribution of endangered and numerically rare butterflies rarely coincides with “hotspots” or centers of biodiversity. Thus, protecting regions of Oregon rich in overall butterfly diversity will not normally protect the bulk of rare or endangered butterfly species. 相似文献
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Katherine C. Kral-OBrien Ryan F. Limb Torre J. Hovick Jason P. Harmon 《Strength and Conditioning Journal》2019,72(2):301-309
Rangeland management strategies impact biodiversity, the quality and quantity of ecosystem services, and overall rangeland resiliency. Previous management strategies, coupled with climate change, have led to widespread invasion by Kentucky bluegrass (Poa pratensis; bluegrass) in the Northern Great Plains, United States. Bluegrass invasions are expected to have detrimental impacts on biodiversity conservation and ecosystem services provided by rangelands. Yet none have investigated how bluegrass invasions influence pollinator populations, which are a prominent conservation concern and provide ecosystem services. We measured the impact of bluegrass invasion on mixed-grass prairie forb and butterfly communities. Obligate grassland butterflies, those that rely on grasslands, decreased as bluegrass cover increased, including the threatened Hesperia dacotae. Conversely, the abundance of facultative grassland butterflies, those found in grasslands but not fully dependent on them for their life history, increased as bluegrass increased. Moreover, plant species diversity and flowering forb species richness decreased as bluegrass cover increased. Overall, bluegrass invasion led to butterfly and plant community simplification, signaling a loss of biodiversity and potentially ecosystem services. Our research is the first to quantify how grassland butterflies and the floral resources they depend on are negatively impacted by bluegrass invasion. Resource managers should adopt management strategies that reduce bluegrass cover and improve nectar and host resources for obligate grassland butterflies. Management choices that removed disturbance regimes inherent to the Northern Great Plains (i.e., fire and grazing) led to bluegrass dominance in the region. Therefore, restoring disturbance regimes may be one way to reduce bluegrass and benefit pollinator populations. 相似文献
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重庆市蝶类区系组成研究 总被引:11,自引:8,他引:3
】1990~1997年对重庆市蝶类调查表明,现有蝶类250种,隶属于11科129属。其中,东洋种165种,古北种23种,广布种62种,分别占总种数的66.0%,9.2%和24.8%,以东洋界种类为主要成分。与相邻的湖北、湖南两省蝶类区系共同处多,关系密切,在区系形成演化上可能有相似的历史渊源。 相似文献
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湖南省桑植县及天平山自然保护区蝶类资源调查 总被引:2,自引:0,他引:2
报道了湖南桑植县及天平山自然保护区的蝶类,包括10科共187种,共系分析结果表明,桑植县及天山蝶类资源属于东洋区系范畴,蝶类玩具发布亦为东洋区种类占优势。 相似文献
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根据海南岛最新的蝶类文献资料进行了分类统计,结果表明,海南岛蝶类共计613种,隶属于11个科220个属。并对海南岛资料较全的589种蝶类昆虫进行了区系分析,其中属东洋区系种类的占总数的81.49%,其它跨区系的广布种占18.51%,显然,东洋界的种类占优势。提出了实现海南岛蝶类资源可持续利用的策略。 相似文献
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针对绢蝶属的许多种类外形、翅面斑纹、色彩构成相近和特征不易区分等特点,进行部分种类绢蝶翅面斑纹特征观察、比较。 相似文献
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四川攀枝花地区蝶类记录 总被引:2,自引:1,他引:2
】攀枝花地区蝶类239种,隶属于130属,12科。东洋种154个(64.43%),古北种8个(3.35%),东洋古北共有种71个(29.71%),广布种6个(2.51%),限于中国分布47个,川滇区特有种19个。在中国昆虫地理区划中归属于27个分布型;仅限于川滇、江南、华南3区内分布的种类124个,占总数1/2弱;与横断山蝶类区系有较大差异。调查发现四川蝶类新记录33种。至此,四川蝶类已记录251属698种。 相似文献