CFD Based Study of Heterogeneous Microclimate in a Typical Chinese Greenhouse in Central China

Indoor microclimate is important for crop production and quality in greenhouse cultivation.This paper focuses on microclimate study based on a computational fluid dynamics(CFD) model of a typical plastic greenhouse(with a sector shape vertical cross-section) popularly used in central China.A radiation model is added into the CFD model so as to simulate coupling of convective transfers and radiative exchanges at the cover and the roof,instead of using the usual coupling approach based on energy balance.In addition,a fractal permeability model is innovatively adopted in the modeling of the crop canopy.Compared the numerical results with measured experimental data,the model simulation is proved with success.This model then is used to explore the microclimate variable distributions in the greenhouse.It shows that the airflow pattern,temperature and humidity profiles are different from those in a sawtooth Mediterraneantype greenhouse.The study suggests that this deliberately developed CFD model can be served as a useful tool in macroclimate research and greenhouse design investigating.     

Studies on Methane Emissions from Pastoral Farming in New Zealand

The aim of this paper was to give a basic understanding of studies on methane emissions of New Zealand, as we know the agriculture of New Zealand is pastoral farming, most livestock animals are grazed in pasture, and quantities of methane were released from the digestive tract and animals excreta. In New Zealand some 50% greenhouse gases （GHG） sources are attributed to agriculture and one third is methane from livestock enteric formation. For many years, many researchers have been exploiting the techniques and methods to measure the emission of methane of New Zealand, further more studing the available options to alleviate the methane emissions. Their pioneering work and successful experiences including the determined methods and mitigation strategies are worth learning for scholars around the world. Some of their approaches were not only suitable for New Zealand grazed livestock, but for many other countries, even the animals are intensively bred in pen. The calorimeter/respiration chamber is the most exactly method in present, but it needs expensive equipments and skilled manipulators, so there are still some difficulty in applying this approach extensively in practice. Sulfur hexafluoride （SF6） trace technique is much adopted for grazed livestock evaluating the methane emission, though its veracity was doubted by some researchers, it is still a good option in present for studying the GHG emissions for grazing animals. By measuring the rumen volatile fatty acid （VFA） concentration to estimate the methane emission is a relatively simple approach, it is just only a rough evaluation, and it is unsuitable for exact study, but this method may be used in China for extensively raised ruminant. In present China, the ruminants are fed in an extensively managed state, the diversities of roughage and animals varieties caused difficult to exactly estimate the methane emission. So exploiting the available options is much important for constituting the exhaustive emission inventory. This review just maybe a good reference for researchers to carry out their studies in years and acquired great achievements in methane mitigation area. outline some practical techniques of New Zealand, those this field, after all New Zealand have been persisting many     

Impact of the red imported fire ant Solenopsis invicta Buren on biodiversity in South China: A review

The red imported fire ant, Solenopsis invicta, is a problematic invasive species in China since at least 2003. Over the past 15 years, a numerous studies were published on the impacts of this species on flora, fauna, and ecosystem function in natural and agricultural systems. We reviewed the literature on S. invicta invasion biology and impacts on biodiversity in South China. Both monogyne and polygyne colonies of S. invicta were introduced to China and polygyne colony is the dominant type. The range expansion rate of S. invicta may reach 26.5–48.1 km yr–1 in China. S. invicta forage activities occur year-round, peaking in the summer and fall in South China and show a preference for insects and plant seeds. We describe the ecological impacts of S. invicta on various habitats in South China, including arthropod community structure disruption and decreases in diversity and abundance of native ant species. S. invicta can replace the role of native ants in mutualisms between ants and honeydew-producing Hemiptera, which results in loss of important food resources for native ants and natural enemies of hemipterans. Further research is required to assess the complex ecosystem-level impacts of S. invicta in introduced areas.     

Journal of South China Agricultural University

Sponsored by South China Agricultural University, Journal of South China Agricultural University publishes a wide range of papers in Agricultural Sciences. Featuring in the Plant Protection Section for publishing regular articles, Journal of South China Agricultural University maintains a leading position in publishing papers in agricultural sciences in China. It is one of China＇s core journals in comprehensive agricultural sciences and in agricultural plant protection, and also the award - winning journal for many times. It is abstracted and indexed in more than 30 digest journals and databases.     

Impacts of Climate Change on Agriculture and Adaptive Strategies in China

China is the world’s most populous country and a major emitter of greenhouse gases. Consequently, China’s role in climate change has received a great deal of attention, whereas the impact of climate change on China has been largely ignored. Studies on the impacts of climate change on agriculture and adaptation strategies are increasingly becoming major areas of scientific concern. However, the clear warming that has been sounded in China in recent decades has not been matched with a clear assessment of the impact of climate change on China’s water resources and agriculture. In the present study, we review observations on climate change, hydrology, and agriculture in China and relate these observations to likely future changes. We also analyse the adaptive strategies in China’s agriculture.     

Breeding the Mite-Resistant Honeybee by Nutritional Crossbreed Technology

Mite （Varroa destructor） is one of the most serious parasite threats to the honey bee （Apis mellifera） reared in China. The beekeepers mainly use the drug to control and kill the mite in the past years, but the honey products may be contaminated and the mite is becoming drug-resistant. The main idea of this paper is to research the possibility of mite-resistant honeybee rearing by nutritional crossbreed. The larvae （Apis mellifera ligustica） are bred with the royal jelly of Apis carana carana, and then the morphological index of the worker generation, genotypic frequency and gene frequency of the MDH Ⅱ, genetic resemblance, and mite resistance are measured. The results show that： compared to the parent workers, the proboscis length, anterior wing area, the total length of the third and fourth dorsal plate of the abdomen, the length of the fourth dorsal plate of the tuberculum, the area of the sixth abdominal segment, and the area of wax mirrors are significantly different, but the differences in the brachium index, dactylus index, and wing claw are not significant. Moreover, there are some mutations in the genotypic frequency and gene frequency of the MDH Ⅱ. The mite resistance of the nutritional crossbreed worker is significantly higher. The morphological, physical, and biochemical characters, genetic resemblance, and the mite-resistant ability of the worker generation can be changed by nutritional crossbreeding. Nutritional crossbreeding can be a new way to breed the honeybee.     

The Global Fur Industry： Trends,Globalization and Specialization

The fur industry and the entire fur cluster are in many ways an interesting and instructive example from which many lessons can be learned. Up to now, the international fur industry has not been thoroughly described or analyzed. A major reason is the rather limited availability of national and international statistics about the fur sector. This article analyzes the production and international trade in fur based on information from official statistics, trade associations, companies, scientific papers and reports, interviews with experts, etc.. Markets and market conditions play a very important role with regards to the fur sector, and the price of fur is volatile in the short and long run. A new world trade pattern and international specialization have emerged in recent years. The comparative advantages of the fur sector change along the fur value chain, while China＇s position on the global fur market has changed significantly.     

Adaptation Strategies to Climate Change in China-A Case Study of Heilongjiang Province

Climate change is one of the most significant environment issues in the whole world today. And it is one of the most complex challenges of the humanities faced in the 21st century. Climate Change is impacted on our global; nobody can avoid the influence of climate change. The local adaptation strategies on climate change are very important to contribute the mitigation and poverty stricken situation, both in China and in the world. We chose a typical China’s province as a case to analyze the impact of climate change on the region (such as agricultural, natural ecosystems, water resources, as well as local people healthy condition), and how the local government and local residences face the impact of the climate change influence, and summarized several strategies on climate change of the area in a sustainable development way.     

Sequence Analysis of mtDNA COIGene and Molecular Phylogeny of Different Geographical Populations of Bemisia tabaci （Gennadius）

Bemisia tabaci(Gennadius) is a serious pest in many cropping systems worldwide and occurs in different biotypes. The mtDNA COIgene of the 12 Bemisia tabaci (Gennadius) populations from different regions and countries were analyzed. Based on mtDNA COI sequences, their biotypes were characterized and phylogenetic relationships among these populations were established with the method of UPGMA. The results indicated the genetic similarity between those populations from Beijing, Zhengzhou, Zaozhuang, Nanjing, Shanghai, Haikou, and the B-biotype populations from California, Texas, Arizona reached 99.8-100%, which meant the nation-wide infested populations of B.tabaci in China in recent years were B-biotypes. Another population collected from Kunming of Yunnan Province showed very high similarity with Q-biotype B.tabaci from Spain and Morocco, which meant the Kunming population was Q-biotype. This is the first report on the invasion of Q-biotype into China.     

中国皮刺螨总科名录初报

医学革螨非是昆虫类节肢动物的统称,可以作为多种疾病的传播媒介。皮刺螨总科是医学革螨的重要组成部分,结合国内关于革螨区系研究的诸多文献报道,在《中国经济昆虫志》(第40册)的基础上,新增了9属126个新种,丰富和扩展了皮刺螨总科的内容。     

我国医学革螨生态学研究概况

医学革螨的生态学是医学蜱螨学的一个重要组成部分,对于指导螨媒疾病的监测和控制具有重要的医学意义。结合医学革螨的相关文献,从革螨生态学的个体、种群、群落3个不同组织层次探讨了我国医学革螨生态学的研究概况,以期对螨媒疾病的监测和控制提供指导。     

神农架自然保护区土壤动物群落多样性的研究

在神农架自然保护区7种生境中土壤表面共获取土壤动物2 467只,分别隶属于21个类群,类数组成以高草最丰富,草地最贫乏。其中,甲螨类和革螨类为优势类群,分别占土壤动物全捕获量的64.17%、16.70%,其他种类为常见类群和稀有类群。两两相比,7种生境相似性指数较高。在7种生境中,杉树林、竹林和原始林生境中多样性指数较高,表明生境条件较优越。     

山楂叶螨在苹果不同品种上的生长发育及繁殖研究

室内实验结果表明,山楂叶螨在苹果不同品种上的生长发育和繁殖有较大的差异。其中在红星上存活率高,发育速度快,生殖力强,而在秦冠上存活率低,发育速度慢,生殖力弱。对山楂叶螨种群年龄结构的分析表明,卵在种群中所占比例较高,而成虫所占比例甚低,建议在对其进行防治时选用杀卵力强的药剂。     

侧多食跗线螨对麻疯树的为害及防控

侧多食跗线螨是农林上最重要的广食性害螨种类之一,对新兴能源植物麻疯树构成极大的潜在威胁.文章综述了国外对侧多食跗线螨为害麻疯树的相关研究报道,介绍其为害特点、形态特征、生物学特性、发生发展规律、主要发生区、监测检测方法及防治措施等.侧多食跗线螨在我国分布广泛,相关麻疯树种植区要积极做好该害螨的发生监测与科学防控工作.     

食用菌螨种类研究进展

螨害是食用菌生产的突出问题之一,本文综述了我国食用菌螨种类研究进展现状,目前我国食用菌螨类主要有29科,重点阐述了福建食用菌螨类隶属23科,52种,阐述了国内外食用菌捕食性螨类应用研究情况,对目前存在的问题及应用前景进行了展望,以期为食用菌生产和害螨防治提供理论依据,并为捕食螨的生物学和应用技术研究提供理论参考。     

蔬菜新害螨—吸腐薄口螨 Histiostoma sapromyzarum(Dufour)记述

本文记述了为害石刁柏的一种新害螨吸腐薄口螨的形态和为害习性。     

虫源性柑橘果面伤痕诊断

我国超过巴西成为世界上柑橘生产第一大国,而我国柑橘出口量排在全球第六名,仅为全球出口总量的6.5%,影响出口因素之一是果实外观品质低下。由于生物、机械和化学等因素在果实生长期对果实外表造成伤害,使成熟果实留下疤痕。造成柑橘果面伤痕的虫害主要有蓟马、螽蟖、螨类、蚧类、卷叶蛾、潜叶蛾、叶甲类、叶蝉、蜗牛等,根据近几年的研究调查并结合国内外相关文献,综述了主要虫源性柑橘果面伤痕症状,为快速准确诊断害虫种类,制定有效的防治措施提供依据。     

基于推荐用量的我国果蔬小型害虫登记用药现状分析

【目的】 通过分析我国果蔬小型害虫登记用药现状,为果蔬小型害虫所用杀虫剂的登记管理和合理减施提供数据参考。【方法】 于2020年6月30日自中国农药信息网查询我国果蔬上登记的用于防治烟粉虱、白粉虱、蓟马、叶螨、蚜虫、介壳虫、斑潜蝇、黄条跳甲、木虱和锈壁虱10种主要小型害虫的杀虫剂,对登记的杀虫剂单剂及混剂的条目数量进行整体分析,并对所有单剂有效成分及其不同剂型的登记条目数进行分析,从中筛选出高用量单剂有效成分,分别从剂型和防治对象上进行用量分析,再将用量最高的6种有效成分、5种作物和5种防治对象进行组合,对已登记的组合进行用量分析。【结果】 登记防治蚜虫和叶螨的杀虫剂数量远多于其他类小型害虫;有效成分用量最大值、均值和范围排序前5位的小型害虫依次为叶螨、介壳虫、蚜虫、白粉虱和锈壁虱,并从中筛选出15种高用量单剂有效成分,其中石硫合剂、呋虫胺、三唑锡、吡虫啉、敌敌畏和松脂酸钠6种杀虫剂单剂有效成分存在用量差异大和离群高值点多的问题突出;登记杀虫剂单剂有效成分用量较高的剂型有结晶（粉）、水剂、可溶粉剂、水乳剂、烟剂和颗粒剂,用量较高的作物为苹果树、柑橘树、黄瓜（保护地）、黄瓜和十字花科蔬菜;三唑锡-柑橘树-叶螨和石硫合剂-苹果树-叶螨两种组合用量差异大并离群高值点多,究其原因可能与剂型和厂家有关。【结论】 为减少杀虫剂用量,减缓小型害虫抗药性发展,建议在最低有效剂量研究基础上,减少登记推荐用量异常高的农药产品,推荐有效成分用量较低的高效低风险杀虫剂品种。     

亮热厉螨越冬虫态与场所

亮热厉螨(Trapilaelaps clareue)的越冬问题,在养蜂界说法不一,通常认为在西方蜜蜂群内的封盖子脾上越冬。经初步观察试验,其越冬场所以封盖子脾为主,南方温暖地区也可在群外的空脾和花粉脾中越冬,还可在某些动植物上渡过短促的越冬期。越冬虫态是成螨。