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701.
太原市城市道路中植物绿化多样性现状及评价 总被引:2,自引:0,他引:2
实地调查了太原市12条主要道路的绿化现状。结果表明:按照出现频率来看,常绿树与落叶树比为1∶2.8;乔木与灌木比为1.1∶1,仅从比例来看,太原城市绿化植物配置还不尽合理。另外,通过调查发现太原市道路绿化植物种类单一,植物色彩单调以及空间利用不足。同时,对其不足之处提出相应改进建议:乔、灌、藤、草相结合并且要体现四季性;配置妥当,使植物在不同的季节呈现不同的色彩;乔、灌、藤、草以及地被植物搭配种植以提高空间利用率。从而逐步建立多层次、多结构、多功能的城市绿地植物群落。 相似文献
702.
703.
This study outlines the importance of integrating spotlighting data and occupancy modelling to estimate the spatial occupancy, abundance and habitat preferences of Cape hares Lepus capensis in southern Tunisia. Exploring the spatial distribution pattern of this species is problematic because of its nocturnal and secretive behaviour. In order to overcome these constraints, we used spotlight surveys on equidistant points along tracks to collect presence/absence data. Using a likelihood-based approach, we estimated occupancy and relative abundance of Cape hare populations in three national parks: Sidi Toui, Bouhedma and Jbil. We also combined the three parks in a single area to represent ‘southern Tunisia’ for investigating the factors affecting its distribution pattern. Sidi Toui showed the highest occupancy and relative abundance values (88.84 ± 10.95% and 7.97 hares km?2, respectively). Bouhedma was also recognised as high-quality hare habitat with occupancy and relative abundance values of 61.70 ± 11.70% and 2.85 hares km?2, respectively. The lowest occupancy (49.65 ± 26.25%) and relative abundance (2.10 hares km?2) estimates were encountered in Jbil. The combined parks model suggested that part of the distribution pattern of Cape hares can be explained by habitat quality. Spatial occupancy over southern Tunisia showed a positive relationship between its occurrence and the availability of Poaceae and Plantaginaceae. 相似文献
704.
为了探究CD46基因在新疆褐牛不同组织中的表达丰度差异,初步掌握CD46基因在新疆褐牛不同组织中的表达规律,试验设计了特异性引物,应用实时荧光定量PCR技术分析新疆褐牛心脏、肝脏、脾脏、肺脏、肾脏、小肠、大肠、胃、肌肉、卵巢和乳腺中的CD46基因表达情况。结果表明,新疆褐牛CD46基因在所检测的11种组织中均有表达,不同组织部位的表达存在差异,其中肝脏CD46表达丰度最高,其表达丰度显著高于肺脏、脾脏、肾脏、胃、小肠、大肠、卵巢和乳腺(P< 0.05)。本研究对新疆褐牛各组织CD46基因的表达规律进行初步分析,为CD46基因表达规律与其生物功能研究的开展提供了参考依据。 相似文献
705.
Evaluation of habitat requirements of small rodents and effectiveness of an ecologically‐based management in a hantavirus‐endemic natural protected area in Argentina 下载免费PDF全文
Hantavirus pulmonary syndrome is a severe cardio pulmonary disease transmitted to humans by sylvan rodents found in natural and rural environments. Disease transmission is closely linked to the ecology of animal reservoirs and abiotic factors such as habitat characteristics, season or climatic conditions. The main goals of this research were: to determine the biotic and abiotic factors affecting richness and abundance of rodent species at different spatial scales, to evaluate different methodologies for studying population of small rodents, and to describe and analyze an ecologically‐based rodent management experience in a highly touristic area. A 4‐year study of small rodent ecology was conducted between April 2007 and August 2011 in the most relevant habitats of El Palmar National Park, Argentina. Management involved a wide range of control and prevention measures, including poisoning, culling and habitat modification. A total of 172 individuals of 5 species were captured with a trapping effort of 13 860 traps‐nights (1.24 individuals/100 traps‐nights). Five rodent species were captured, including 2 hantavirus‐host species, Oligoryzomys nigripes and Akodon azarae. Oligoryzomys nigripes, host of a hantavirus that is pathogenic in humans, was the most abundant species and the only one found in all the studied habitats. Our results are inconsistent with the dilution effect hypothesis. The present study demonstrates that sylvan rodent species, including the hantavirus‐host species, have distinct local habitat selection and temporal variation patterns in abundance, which may influence the risk of human exposure to hantavirus and may have practical implications for disease transmission as well as for reservoir management. 相似文献
706.
佳乐麝香与镉复合污染对土壤微生物群落功能和丰度的影响 总被引:3,自引:2,他引:1
为考察佳乐麝香(HHCB)和镉(Cd)复合污染对土壤微生物群落的影响,采用Biolog和q PCR技术对土壤微生物群落的功能多样性和丰度进行研究。研究发现,HHCB及其与Cd复合污染提高了土壤微生物对碳源的利用能力,6大类碳源利用中以对酯类利用效率最高,对糖类和羧酸类利用效率较低。HHCB污染下,Shannon、Simpson和Mc Intosh指数没有显著性变化,500、1000 mg·kg-1HHCB与Cd复合污染下三种指数显著提高。HHCB加入后,土壤微生物的种群丰富度提高,优势种群增加,种群间的均一性被打破。500、1000 mg·kg-1HHCB及其与Cd复合污染显著促进了细菌生长,HHCB污染显著抑制了放线菌生长。细菌的丰度随HHCB浓度的增加而增加,真菌和放线菌的丰度则随着HHCB浓度的增加而降低,放线菌受HHCB与Cd的影响比细菌和真菌更敏感。 相似文献
707.
708.
Rongping Wang Xinrong Liao Weimin Yu Shuyi Li Zhenshou Zhan Jiawei Liang 《Journal of plant nutrition》2017,40(18):2571-2586
Here, we established abundance and deficiency indices of soil nutrients and fertilization to generate a reference for the optimum fertilization dosage of the main vegetable crops in southern China under current production conditions. We consolidated 3414 field datasets about the main vegetable crops (leafy vegetables, gourds, legumes) in this region between 2010 and 2013. The nutrient abundance and deficiency index method was used to separate soil alkali-hydrolyzable nitrogen, available phosphorus, and available potassium levels into five groups based on relative vegetable yields (range: 50%–95%). Recommended fertilizer dosages were determined by obtaining values for nitrogen, phosphorus, and potassium by fitting optimum dosage against available nutrient content. Required fertilization levels were dependent on soil conditions and crop type. Comparison of the study results showed that available phosphorus and available potassium had significantly improved, whereas alkali-hydrolysable nitrogen in each level was similar. 相似文献
709.
青岛崂山主要植被类型及物种丰富度研究 总被引:3,自引:0,他引:3
为保育恢复青岛崂山主要植被,提高森林覆盖率,采用典型样地法,对青岛崂山现存植被主要类型进行调查,结果表明:崂山地形复杂,气候多样,植物种类繁多,加之人工引种栽培,形成了多样的植被类型,且不同海拔分布着不同的植被类型,其中针叶林分布广泛,主要建群种是赤松(Pinus densiflora);阔叶林主要是有落叶阔叶林构成,主要树种有麻栎(Quercus acutissima)、栓皮栎(Quercus variabilis)等;灌草丛以中生或旱中生多年生草本植物为主要建群种,建群层为草本层;不同海拔,科、属、种丰富度不同,且物种丰富度在中海拔地区较高;北九水,蔚竹庵,太清宫,流清河,凉清河,仰口等地具有较高的物种丰富度,双石屋、冷翠霞、观崂村等样地物种丰富度较低。 相似文献
710.
岱衢洋鱼类资源及其群落多样性的季节变化 总被引:3,自引:1,他引:2
根据2010年春季(5月)、夏季(8月)、秋季(11月)与2011年冬季(2月)对岱衢洋进行的共4个航次的底拖网渔业资源调查资料, 对该海域的鱼类资源状况及其多样性进行了分析, 结果表明: 所捕获的38种鱼分别隶属于1门2纲8目21科31属; 暖温性鱼类无论在种类数量还是生物量与尾数密度方面均居主导地位; 凤鲚四季均为该海域的优势种; 在时间分布上, 生物量与资源尾数密度均以夏季为最高, 而冬季则恰好相反, 且该两季的生物量与资源尾数密度间均存在显著差异(P<0.05), 另外, 在空间分布上, 生物量与尾数密度四季总体上均呈北高南低、东高西低的趋势; 生物量与平均底层温度呈二次曲线相关(P<0.01); 春、秋两季的Margalef丰富度指数( D )、Shannon-Wiener多样性指数( H' )和Pielou均匀度指数( J' )均存在显著差异(P<0.05); 与东海近、外海海域鱼类群落的多样性比较, 岱衢洋的Shannon- Wiener多样性指数( H' )较低。 相似文献