基于Landsat 8的东莞市热岛效应研究   总被引：2，自引：2，他引：0  

沈德才  杨燕琼  吴振彪  陈跃洲 《广东林业科技》2014,30(6):20-24

以2014年广东省东莞市Landsat 8卫星的热红外波段数据建立模型,反演东莞市地表温度,研究东莞市热岛效应分布情况,从优势度指数、分维数指数和形状指数来分析热力场景观格局,根据热岛效应的不同影响因素分析东莞市热岛现象的成因。结果表明：Landsat 8卫星影像反演2014年东莞市地表温度是可行的;东莞市热力景观以中热岛为主,热岛效应不明显,分布呈西北偏高,中部地区和东南区域偏低;热力景观斑块较复杂、热力场呈条带状零星分布;受绿化、水体影响区域的热岛强度较小,而受人为热源、道路、城市下垫面和建筑等因素影响的区域,热岛强度较大。  相似文献   

不同施肥处理对3种海岛树种苗木生长及造林效果的影响     

费行海  ;徐嘉科  ;陈闻  ;王国明 《山东林业科技》2014,(3):50-53

为了解不同施肥处理对普陀樟(Cinnamomum japonicum var.Chenii)、全缘冬青(Ilex integra Thunb.)、红楠(Machilus thunbergii Sieb.et Zucc)3种海岛树种苗木生长及造林效果的影响,设置了7个不同的施肥处理,即(1)N(对照),(2)N+P,(3)N+2P、(4)N+K、(5)N+2K、(6)N+1P+1K、(7)N+2P+2K,于2011年5月至2012年1月观测苗高和地径,并测定植物各部分的生物量。结果表明:3种苗木不同施肥处理下,通过测算苗木质量指数QI可知,在N+1K施肥组合下,全缘冬青的苗木质量最好,而红楠在N+2P+2K的施肥组合下苗木质量最高,普陀樟在N+1P+1K的施肥组合下,苗木质量要好于其他处理。  相似文献   

国际旅游岛建设背景下海南发展休闲农业的对策研究   总被引：1，自引：0，他引：1  

陈燕羽 《广东农业科学》2014,41(19):232-236

国际旅游岛建设对海南休闲农业的发展提出了新的要求.通过分析海南休闲农业发展的现状和现实意义,存在的优势和劣势,面临的机遇和挑战,结合海南热带农业资源特色、生态环境、文化民俗等,从海南休闲农业的发展模式方面提出了“琼北、琼南、琼东、琼西和琼中”5个规划区域,提出从加强体验经济开发、挖掘乡土文化特色和提高科技含量等方面来提高产品的开发档次和内涵,并针对构建投融资体系、制定优惠政策以及加强规范化管理,提高服务水平等方面提出了具体的对策,以期为海南休闲农业的发展提供参考.  相似文献   

Local and remote physical processes driving variability of the planktonic system in the Juan Fernández Archipelago: A multidisciplinary framework providing conservation insights     

Carolina Parada  Billy Ernst  Sebastián Cornejo-Guzmán  Francisco Santa Cruz  Marco Sandoval Belmar  Pablo Rivara  Braulio Tapia  Stéphane Gauthier  Josefa Pino-Aguilera  Ruben Escribano  Carmen E. Morales 《水产资源保护:海洋与淡水生态系统》2021,31(2):253-272

1. The Juan Fernandez Ridge, a vulnerable marine ecosystem located far off the coast of central Chile and formed by several seamounts, guyots and three islands (Robinson Crusoe, Santa Clara and Alejandro Selkirk), has recently been declared a Coastal Marine Protected Area of Multiple Uses with several National Parks embedded in it.
2. Recent studies have highlighted the influence of remote and local oceanographic structures on the hydrographic dynamics of this ridge. However, there is still a gap in understanding how they affect the structure and dynamics of the surrounding insular planktonic communities.
3. A hydroacoustic and oceanographic survey was conducted during the austral spring (October 2016), including hydrographic and zooplankton sampling around Robinson Crusoe Island. Oceanographic features were identified and tracked using satellite data (chlorophyll-a (Chl-a) and sea surface temperature) and modelling results.
4. Two events of Chl-a increase relative to a threshold (>0.45 mg m⁻³) were forced by different physical processes, both affecting the western side of Robinson Crusoe Island. In event A during the cruise period, Chl-a subsurface maxima were associated with the arrival of a coastal meander originating on the continental shelf off Chile (remote process); the zooplankton was dominated by copepods and salps, with an evident coastal–oceanic gradient. In event B, Chl-a maxima were linked to a local upwelling forced by the intensification of a localized SSW wind. No influence of remote eddies or local Von Kármán vortices on Chl-a distribution was observed.
5. These findings highlight the influence of remote and local physical processes on the structure of planktonic communities around Robinson Crusoe Island. Understanding the variability of these mechanisms and their effects at the base of the pelagic food web is critical in adopting an ecosystem-level approach.

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Temporal changes in seabird assemblage structure and trait diversity in the Rapa Nui (Easter Island) multiple-use marine protected area     

Paula Plaza  Juan Serratosa  Joao B. Gusmao  David C. Duffy  Paulina Arce  Guillermo Luna-Jorquera 《水产资源保护:海洋与淡水生态系统》2021,31(2):378-388

1. For Rapa Nui (Easter Island) and its largest islet, Motu Nui, the change of the species assemblage over time was analysed, and a trait-based approach to evaluate the potential losses in seabird function across the past centuries was applied. At a finer scale, the seasonal changes in seabird species composition in the current seabird assemblage was assessed to better understand the dynamics of the long-term inferred patterns.
2. For Rapa Nui, the composition of the seabird assemblage between the prehistorical, historical, and current time has changed significantly. The most critical change, probably associated with human colonization, was observed between prehistoric and current times. The current diminished number of nesting seabird species was probably the result of local extirpation without evidence of colonization by new species.
3. For Motu Nui, changes in species composition were also followed by changes in trait structure, which were smaller than observed in Rapa Nui. This is probably due to the presence of a relatively high number of related species (i.e. Procellariids) with high similarities in their foraging behaviour.
4. The nesting seabird assemblages in Rapa Nui and Motu Nui differ in exposure to risk; thus, conservation strategies applied to the islands should be planned on a fine spatial scale. For Rapa Nui, which is an urban wildlife area with several invasive species and a low number of remaining native seabird species, management should focus on fencing and pets control. For Motu Nui, management should instead focus on the establishment of quarantine and other biosecurity tools to avoid both the entry and proliferation of new invasive species.

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小鼠基因内含子中CpG岛和几个转录调控元件分析     

李慧敏  陈丹 《广西农业生物科学》2012,31(2):129-132

内含子在基因转录调控中的作用已多次被实验报道,然而对其参与调控的普遍性还缺乏足够的理论支持。本研究利用计算分析方法,对小鼠基因内含子中的CpG岛（CpGisland）、TATA框（TATAbox）、CAAT框（CAATbox）以及GC框（GCbox）等元件的出现频率进行分析。结果发现,分别有56.01%、57.16%、65.88%和41.86%的第一内含子具有CpG岛、TATA框、CAAT框以及GC框,而它们在其它内含子中的平均出现频率则分别为14.07%、45.24%、49.91%和13.19%。即使考虑到不同位置的内含子,这些元件在第一内含子中的出现频率也显著高于它们在其它任何位置内含子中的出现频率。由于CpG岛、TATA框、CAAT框以及GC框均与基因的转录调控有关,据此推测小鼠第一内含子在基因转录调控过程中具有潜在的重要性。本研究结果为内含子参与转录调控提供了更多的理论依据。  相似文献   

基于国际旅游岛建设的文昌现代农业与旅游业发展意见     

林宁  麦全法  蒋菊生 《热带作物学报》2010,30(12):59-64

分析海南国际旅游岛建设的背景下文昌市发展条件与特点，在指出文昌经济发展的六大制约因素及四大潜在动力基础上，重点突出当地农业、旅游业发展方向，提出建设海南高效农业和优质农产品基地、海南东北部优越的度假旅游区、海南东北部高端生活休闲服务区、海南科教文明教育基地四大任务及五大保障措施。  相似文献   

陆地棉与海岛棉干物质累积分配特性   总被引：1，自引：0，他引：1  

郑德明  姜益娟 《塔里木大学学报》1995,7(2):10-13

供试的四个陆地棉品种地上部分干物质累积速度和数量，从现蕾至吐絮始终高于四个海岛棉品种；陆地与棉与海岛棉的所有品种干物质累积速率最快的时间均在初期至有效花期期间。但海岛棉干物质累积最大量到８月２５日止，陆地棉则持续到９月９日；不同时期干 物质分配率的特点是；苗期；叶〉茎，苗期：叶〉茎〉蕾，花苗期：叶〉茎〉铃〉蕾〉花；铃期；铃〉茎〉叶；株铃重累积的最快速率时间，陆地棉与海岛棉均在７月２６日至８月２５日  相似文献   

The influence of fruit abundance on the use of forest and cultivated field habitats by the endemic Madeira laurel pigeon Columba trocaz: Implications for conservation     

Paulo Oliveira  Dilia Menezes  Martin Jones  Manuel Nogales 《Biological conservation》2006,130(4):538-548

This study was conducted over a two year period in the north west of Madeira Island (Macaronesian Atlantic Islands, Portugal). It investigates the relationship between fruiting patterns in the indigenous forest and the use by the Madeira laurel pigeon of forest habitats and cultivated areas. Habitat use observations were carried out using line-transects in forest sites where the availability of fruit (the most important element of the diet) was assessed. The use of agricultural fields was measured indirectly by the assessment of the damage caused to crops. The findings provided strong evidence that bird movements and shifts in abundance are related to fruit usage and availability. The use of fruits is mostly opportunistic but when many species are available, selection was observed. From an ecological perspective, our findings indirectly confirm a high concordance between pigeon diet, studied by microhistological techniques, and habitat use. The use of crops also seems to be mostly opportunistic and is governed by the birds’ movements within the adjacent forest. It is hypothesised that fruit phenology will influence the use of agricultural areas only to the extent that it governs such movements; there is no strong evidence that crops are attacked only when the availability of natural foods is low. Our results suggest that the current management strategy for the forest is adequate for the conservation of this pigeon but that the conservation value of forest edges should be redefined. It is also proposed that crop damage may be reduced by identifying the proximate factors, which lead to the use of specific fields.  相似文献   

英语词汇与英国文化特色     

戴卫平  高丽佳 《湖南农业大学学报(自然科学版)》2005,(2)

英语是英国文化的产物,因此必然要烙上不列颠文化的印记。剖析英语词汇这块英国文化的化石,我们可以领悟英国这个“岛国”所特有的文化内容。  相似文献