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81.
82.
广西龙虎山自然保护区种子植物区系分析 总被引:5,自引:0,他引:5
本文对广西龙虎山自然保护区种子植物区系进行分析。龙虎山有野生种子植物851种,隶属136科536属。龙虎山区系世界分布科占25.0%,热带分布科占59.6%,温带分布科占15.4%。热带分布占本区系总属数的80.6%;温带分布占本区系总属数的18.4%,中国特有分布属占1.0%。龙虎山种子植物区系具有明显的热带性质和岩溶区系性质,特有现象较丰富。 相似文献
83.
基于斑块尺度的生境适宜性研究,可以通过物种分布的景观格局特征,推导出研究区的景观适宜性,有利于景观规划决策。研究首先分析农业用地对神农架川金丝干扰的阈值,其次采用泊松回归构建基于斑块尺度的包含植被类型、斑块特征和人为干扰特征的猴群分布模型,依据模型结果叠加道路适宜性分级图对川金丝猴适宜生境进行评价。结果显示:(1)农业用地干扰阈值为2000 m;(2)最优模型显示猴群偏好面积大、形状简单的寒温性针叶林、寒温性针叶-落叶阔叶混交林、温性针叶-落叶阔叶混交林斑块,对农业用地具有回避性;(3)道路干扰已成为川金丝猴迁移的主要障碍,川金丝猴分布区受到的农业干扰较小,但其成为阻碍川金丝猴扩张分布区的屏障。建议神农架保护区全面开展道路与旅游景点对野生动物干扰的监测。 相似文献
84.
名山县位于东经103°08′,北纬30°06′,是四川省商品粮油基地县之一,属川西盆周丘陵地区。年平均气温15.5℃,日照1052.0小时,降雨量1519.9mm,一年两熟,能满足油菜全生育期的需要。全县油菜发展较快,1989年较1983年种植面积扩大了33.91%,达到6000ha;总产增加30.35%,达到5958.1t。 相似文献
85.
为明确甘肃兴隆山国家级自然保护区内的蝴蝶种类, 以及不同生境的蝴蝶群落结构与种-多度分布的变化情况, 在全部5个林场选取6条样线, 于2015-2018年连续4年采用样线法对保护区的蝴蝶进行调查和采集, 并分析了其多样性指数及种-多度分布。4年共采集蝴蝶标本5,719号, 经鉴定隶属8科69属120种。眼蝶科(3,093号)是保护区的优势类群, 喙蝶科仅采集到1号标本(朴喙蝶, Libythea lepita), 为保护区的稀有种类。其中, 各样线的种数、个体数、多样性指数以及物种丰富度表现为: 样线I最高, 样线IV次之, 说明其生境结构稳定, 环境良好, 适合蝶类生存; 样线III蜜源植物丰富, 各项指数较高; 样线V海拔较高, 各项指数较低; 样线II植物群落结构单一, 各项指数最低。相似性系数分析结果表明: 样线I和VI、III和IV、III和VI均为中等相似; 其余各样线间为中等不相似。区系分析结果表明: 古北种有63种, 占总种数的52.5%; 东洋种2种, 占总种数的1.7%; 广布种55种, 占总种数的45.8%。说明古北种占绝对优势, 且明显高于东洋种, 具有很强的地区代表性。种-多度分布分析结果表明: 样线I和IV呈现出对数正态分布, 模型拟合效果较好; 样线II和VI为非典型的对数级数模型, 符合生态位优先占领假说。说明不同生境以及人为干扰因素与蝶类多样性关系密切, 表现出单一生态系统蝴蝶群落的多样性指数较低, 复杂生态系统其多样性指数较高的特点。 相似文献
86.
Xuejun Zhang Shengliang Ye Xi Du Jing Yuan Chaoming Zhao Changqing Li 《Biologicals》2013,41(6):364-367
In 2007, the Chinese State Food and Drug Administration (SFDA) implemented a management system for lot release of all plasma-derived products. Since then, there have been only a few systematic studies of the blood supply, which is a concern when considering the small amount of plasma collected per capita (approximately 3 L/1000 people). As a result, there may be a threat to the safety of the available blood supply. In this study, we examined the characteristics of the supply of Chinese plasma-derived products. We investigated the reports of lot-released biological products derived from all 8 national or regional regulatory authorities in China from 2007 to 2011. The market supply characteristics of Chinese plasma-derived products were analyzed by reviewing the changes in supply varieties, the batches of lot-released plasma-derived products and the actual supply. As a result, the national regulatory authorities can more accurately develop a specific understanding of the production and quality management information provided by Chinese plasma product manufacturers. The implementation of the lot release system further ensures the clinical validity of the plasma-derived products in China and improves the safety of using plasma-derived products. This work provides an assessment of the future Chinese market supply of plasma-derived products and can function as a theoretical basis for the establishment of hemovigilance. 相似文献
87.
《African Journal of Aquatic Science》2013,38(3):269-276
The construction of Pongolapoort Dam in 1973 on the Phongolo River in KwaZulu-Natal, South Africa, has considerably altered the hydrological behaviour and ecological response of the downstream floodplain. Changes in the flooding regime have had implications for the socio-economic importance of the floodplain and for the structure and functioning of its associated wetlands. Previous studies have recommended annual releases of water from the dam to sustain floodplain ecosystem goods and services. The current artificial water releases are limited by the size of the dam's sluices and by the demand for water from the local community. Therefore, water releases do not always follow the original natural flooding regime. To date, the influence of the changed hydrology on the ecology of the Phongolo floodplain system remains poorly known. As a basis for future integrated interdisciplinary research we synthesised the ecological and hydrological work conducted to date on the Phongolo floodplain. We suggest hydro-ecology as an important research direction needed to set environmental flows for the sustainable utilisation and management of the floodplain. Understanding the hydrological behaviour and ecological response of the Phongolo floodplain could help in the implementation of environmental flows by managers at the Department of Water and Sanitation and other stakeholders such as Ezemvelo KZN Wildlife. 相似文献
88.
Tomasz B. Falkowski José Raúl Vázquez-Pérez Adolfo Chankin Atzin Yetlanezi Campos-Beltrán José L. Rangel-Salazar Jonathan B. Cohen Stewart A.W. Diemont 《Biotropica》2020,52(6):1242-1252
Evidence regarding the ability of agroforests to conserve biological diversity has been mixed; they tend to maintain avian communities with species richness similar to that of undisturbed forest ecosystems but generally do not completely preserve community composition. Using a combination of occupancy modeling and non-metric multidimensional scaling on point-count data, we assessed changes in avian community diversity and composition along a successional gradient in traditional Lacandon Maya agroforests and compared them to protected areas in the region. Bird species richness and diversity in Lacandon agroforests peaked in early secondary forest stages. These agroforests' mean Shannon–Weiner diversity was 5% higher than that of nearby protected areas, but their species richness was similar. Community composition in Lacandon agroforests changed throughout succession, with earlier stages supporting communities distinctly characterized by generalist species, while subsequent, less-intensively managed stages tended to support more forest-dwellers. The bird community observed in even the most mature secondary forest stages in Lacandon agroforests differed from that of undisturbed rain forest ecosystems. These results demonstrate the potential of traditional Lacandon agroforestry management to conserve avian biodiversity while ensuring food sovereignty for farmers. However, because the community composition of early-successional stages was different than later stages, shortening fallow cycles and reducing forest cover to increase agricultural production will limit the species this system can support. This study illustrates the value of incorporating traditional agroecosystems into conservation planning as well as maintaining protected areas, because the latter serve as refugia for species that require undisturbed forest habitat in an agroecological matrix. 相似文献
89.
Termites from the genus Odontotermes are known to contain numerous species complexes that are difficult to tell apart morphologically or with mitochondrial DNA sequences. We developed markers for one such cryptic species complex, that is, Odontotermes srinakarinensis sp. nov. from Maxwell Hill Forest Reserve (Perak, Malaysia), and characterised them using a sample of 41 termite workers from three voucher samples from the same area. We then genotyped 150 termite individuals from 23 voucher samples/colonies of this species complex from several sites in Peninsular Malaysia. We analysed their population by constructing dendograms from the proportion of shared-alleles between individuals and genetic distances between colonies; additionally, we examined the Bayesian clustering pattern of their genotype data. All methods of analysis indicated that there were two distinct clusters within our data set. After the morphologies of specimens from each cluster were reexamined, we were able to separate the two species morphologically and found that a single diagnostic character found on the mandibles of its soldiers could be used to separate the two species quite accurately. The additional species in the clade was identified as Odontotermes denticulatus after it was matched to type specimens at the NHM London and Cambridge Museum of Zoology. 相似文献
90.
《Journal of bryology》2013,35(3):179-188
AbstractTwo new species of Schistidium Bruch & Schimp., S. riparium H.H.Blom, Shevock, D.G.Long & Ochyra, and S. mucronatum H.H.Blom, Shevock, D.G.Long & Ochyra, are described and illustrated. They occur in rheophytic habitats in China, S. riparium in the southern Hengduan Mountains in Yunnan Province (Lancang Jiang and Nu Jiang catchments) and S. mucronatum from further north, on the Qinghai–Tibet Plateau of Sichuan and Qinghai Provinces (Jinsha Jiang and Huang He catchments). The affinities of the new species are discussed and on the basis of their concave and broadly canaliculate leaves with plane and erect margins, S. riparium is tentatively placed in Schistidium Bruch & Schimp. subgen. Canalicularia Ochyra, whereas S. mucronatum on account of its keeled, ovate-lanceolate leaves and the strongly curved and twisted peristome teeth resembles very much species of sect. Apocarpiformia (Kindb.) Ochyra within subgen. Apocarpa Vilh. 相似文献