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101.
农业景观中的鸟类多样性对生态系统功能和服务的形成与维持具有重要作用。黄淮平原区是我国最重要的农业景观区之一,为探讨区域内农业景观中鸟类多样性特征和不同生境间的差异,在研究区农业景观不同生境中布设样点,调查繁殖期鸟类多样性特征。结果显示:(1)共记录到32科、49属、66种的10044只个体,但优势科属明显;(2)物种丰富度、多样性和均匀度均表现出在沟渠、湖泊生境中较高,农田和村庄生境中相对较低,但物种多度呈现出村庄生境中最高,其次是沟渠和农田生境,湖泊生境中最低;(3)在区系分布上,各生境中均以广布种为主,生态类群上,鸣禽在各生境中均占绝对优势,涉禽和游禽主要分布在沟渠和湖泊生境中,从居留型来看,留鸟是各生境中的主导类群,候鸟、旅鸟和迷鸟比例很低;(4)鸟类群落异质性分析显示,各生境间的相似性总体上较高,表明区域内农业景观中鸟类组成具有较高的重叠性。研究显示农业景观中湖泊和沟渠的存在能有效的提高区域鸟类的丰富度和多样性,而沟渠的存在能有效的提高鸟类个体多度,农田和村庄有助于特定类群多度的增加,因此在未来的区域持续农业景观的构建中一方面要重视自然、半自然非农生境的作用,另一方面也不能忽视不同生物类群对景观异质性响应和对生境特征需求的差异。 相似文献
102.
雄安新区白洋淀生态属性辨析及生态修复保护研究 总被引:6,自引:0,他引:6
湿地是自然界生物多样性最丰富的生态系统之一,与社会发展和人类福祉息息相关。近年来,由于全球气候变化和人类活动的过度干扰,湿地正面临着面积萎缩、功能减弱、多样性降低等诸多问题,湿地退化已经成为制约区域可持续性发展的重大阻碍。伴随着生态文明建设逐渐成为中国特色社会主义建设的重要支柱,湿地生态修复工作得到前所未有的制度保障。深入剖析湿地属性,结合政策保障,有针对性的提出湿地保护与修复的治理措施,对区域的生态环境建设和可持续性发展具有重要意义。选择国家级新区-雄安新区的水命脉-白洋淀湿地为研究对象,在深入剖析其生态属性和已存在的生态问题的基础上,结合生态修复的原则、方法和步骤,提出生态修复与保护的可行性策略。研究结果表明,白洋淀本质是典型的湖泊湿地,同时兼具沼泽湿地特征,由于人类活动的剧烈干扰,白洋淀有向沼泽湿地逆向演替的变化趋势。湿地内存在面积萎缩、水资源量短缺、水环境污染问题突出及生物多样性减少等生态问题。本研究建议:为顺利建设雄安新区,首先,白洋淀湿地在算清"水账"、"污账"和"生态账"的前提下,进一步加强流域水资源调配,科学确定白洋淀湿地最佳水位,恢复淀区水量;其次,通过使用清洁生产技术和限制高排污企业建设等措施,加强污染防治,恢复湿地水质;最后,依据生态承载力理论,划分白洋淀流域的生态功能红线、环境质量红线和资源利用红线等国家生态保护红线体系,为尽快恢复湿地结构与功能提供制度保障。 相似文献
103.
Jerry K. Jacka 《The Australian journal of anthropology》2019,30(1):35-52
In this article I consider why individuals sacrifice their lives for the collective. In the Porgera Valley of highlands Papua New Guinea, young men who are called ‘Rambos’ engage in sustained tribal conflicts due to increasing social inequalities in an area that is supposedly benefiting from socioeconomic development. The opening of the Porgera Gold Mine in 1990 ushered in an era of anticipated benefits that were hoped to transform the lives of the region's subsistence horticulturalists. Yet, anticipated flows of mining money and social benefits have largely failed to materialise. The abjection experienced by young men eventuated into a series of tribal fights, resulting in deaths, displacements, and the destruction of most infrastructure. I examine the fighting and its aftermath in relation to anthropologies of the dark and the good and argue that these polar opposites can hinder more subtle understandings of value plurality among Porgerans. 相似文献
104.
Blepharis saudensis, from small islands in the Red Sea of Jazan Provence, Saudi Arabia, is described as a new species and illustrated. This species differs from other known species in this genus by having a combination of long stems, oblong-lanceolate to linear leaves with entire margins and pubescence. 相似文献
105.
Afrouz Farhad Paolo Rosa Ali Asghar Talebi Yaghoub Fathipour Hamidreza Hajiqanbar 《Journal of Asia》2019,22(4):1005-1012
The Iranian species in the Chrysis pulchella and C. varidens species groups are investigated. Six species are recognized, two of which are described for the first time: Chrysis gamberoonensis Farhad, Rosa and Talebi sp. nov. and Chrysis brunneamarginata Farhad, Rosa and Talebi sp. nov.. Chrysis gamberoonensis Farhad, Rosa and Talebi sp. nov. belongs to the C. pulchella group and is recognizable within this species group by its unique blue body coloration, scattered mesosoma punctures, polished pit row with elongated pits, and a small median tooth on the lateral edge of metasomal tergum 3. Chrysis brunneamarginata Farhad, Rosa and Talebi sp. nov. belongs to the C. varidens group and is recognizable by the usually colorless apical rim of metasomal tergum 3, and the unique shape of the anterior corners of the scutellum which are enlarged, thickened and directed backward covering the axillary trough. Dichotomous keys and distributional data for Iranian species included in these species groups are provided. Chrysis schwarzi Linsenmaier, 1968 is raised to species rank. The number of Iranian Chrysis species and subspecies is raised to 122.www.zoobank.org/urn:lsid:zoobank.org:pub:F419F860-3B90-4679-9A19-2CF5C255AE6B 相似文献
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Hanna N. Ststad Melissah Rowe Arild Johnsen Jan T. Lifjeld 《Journal of evolutionary biology》2019,32(7):666-674
Sperm morphology varies enormously across the animal kingdom. Whilst knowledge of the factors that drive the evolution of interspecific variation in sperm morphology is accumulating, we currently have little understanding of factors that may constrain evolutionary change in sperm traits. We investigated whether susceptibility to sperm abnormalities could represent such a constraint in songbirds, a group characterized by a distinctive helical sperm head shape. Specifically, using 36 songbird species and data from light and scanning electron microscopy, we examined among‐species correlations between the occurrence of sperm head abnormalities and sperm morphology, as well as the correlation between sperm head abnormalities and two indicators of sperm competition. We found that species with more helically shaped sperm heads (i.e., a wider helical membrane and more pronounced cell waveform) had a higher percentage of abnormal sperm heads than species with less helical sperm (i.e., relatively straight sperm) and that sperm head traits were better predictors of head abnormalities than total sperm length. In contrast, there was no correlation between sperm abnormalities and the level of sperm competition. Given that songbird species with more pronounced helical sperm have higher average sperm swimming speed, our results suggest an evolutionary trade‐off between sperm performance and the structural integrity of the sperm head. As such, susceptibility to morphological abnormalities may constrain the evolution of helical sperm morphology in songbirds. 相似文献
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