高原鼠兔时空动态的元胞自动机模拟

利用高寒草甸和高原鼠兔(Ochotona curzoniae)的生态特征建立了元胞自动机模型,并通过模拟得到了高原鼠兔种群时空动态的规律。结果表明:高原鼠兔有效洞口的扩散量与扩散力的变化基本一致,扩散可减轻高原鼠兔对高寒草甸的危害;高原鼠兔对原栖息地的留恋指数α越小,高原鼠兔越易扩散;退化草甸上高原鼠兔密度越大,对已治理草地的入侵就越远;退化草甸恢复后,植被低矮时,入侵距离短、危害重,而植被较高时,入侵距离远、危害轻;全球气候变暖后,如果高原鼠兔的繁殖期不延长,则增温前后的种群动态相差不大;如果增温后高原鼠兔的生长期延长,在非退化高寒草甸上,增温前后种群动态差别不大,在退化高寒草甸上,高原鼠兔种群将迅速增大。     

太原市万柏林生态园害鼠发生概况与调查方法比较

利用笼捕和夹捕相结合的方法,对万柏林生态区害鼠种类及种群密度进行了调查。结果表明,该区害鼠发生严重,笼捕率高达46.94%,夹捕率可达28.43%。根据捕获结果,结合现场勘察可以确定至少有6种不同的害鼠在万柏林生态区发生危害,分别为社鼠、岩松鼠、花鼠、褐家鼠、小家鼠和棕色田鼠,其优势鼠种为岩松鼠和社鼠。笼捕法和夹捕法捕获的害鼠种类及捕获效果存在一定差异。笼捕法对岩松鼠的捕获效果较好;夹捕法对社鼠的捕获效果较好,对岩松鼠、花鼠的效果较差。经田间试验,0.005%的溴敌隆毒饵对万柏林区害鼠种群有很好的杀灭效果,可以用于大范围内的灭鼠。     

东北地区水稻初冬晾晒期鼠害调查与为害分析

东北地区是我国重要的商品粮基地, 同时也是鼠害严重发生地区。明确当地鼠害特点, 制定有效防治措施, 对保证我国粮食安全具有重要战略意义。东北地区水稻规模化种植较晚, 对稻田鼠害研究也较少。本研究针对稻田鼠害种类不清、密度难定的问题, 在水稻收割晾晒期内采用“翻稻垛尽捕法”和“夹捕法”调查鼠种组成与密度, 并估算稻谷损失率。结果表明, 尽捕法可捕获5种害鼠, 稻垛鼠密度为197~310只/hm2; 夹捕法只能捕到3种害鼠, 小型鼠缺失; 产量损失估算稻谷损失率约为0.13%~0.52%, 折合每公顷损失约7.8~31.2 kg。结果表明, 两种调查方法可以反映出不同害鼠的空间分布格局差异, 将两种方法结合可获取更多的鼠害信息; 如果适当缩短水稻晾晒期可有效减少害鼠对稻谷的为害。     

应用无人机(UAV)低空影像监测黄兔尾鼠鼠洞初探

黄兔尾鼠是新疆北部地区荒漠草原的主要危害鼠种之一。其灾害调查长期以人工地面调查为主。为探究无人机(UAV)低空遥感在黄兔尾鼠鼠洞调查中的适用性,选择巴音沟牧场典型鼠害区进行航拍试验,采用小型无人机作为低空遥感平台,获取研究区可见光航拍影像。采用极大似然法和面向对象分类方法提取鼠洞,通过混淆矩阵结合地面样方对分类结果进行精度评价。结果表明,应用UAV监测黄兔尾鼠洞穴的空间分辨率应不低于1.5 cm;极大似然法鼠洞分类精度为69%,而面向对象分类方法分类精度达91%,面向对象分类方法识别鼠洞正确率更高。UAV低空遥感在黄兔尾鼠灾害调查中表现良好,具有很好的应用和推广价值。     

新疆木垒县草原兔尾鼠种群数量的动态变化

20 0 0年 9月至 2 0 0 1年 9月在新疆木垒县分 4个时段采用样方法对草原兔尾鼠 (Laguruslagurus) 进行野外调查 ,实验室应用Leslie矩阵模型预测了该地区草原兔尾鼠种群数量变化的趋势。结果表明 ,在该矩阵中引进一个存活系数 ,能够使预测值与实际观察值有较好的拟合结果。     

新疆乌苏沙湾地区2005～2006年秋季黄兔尾鼠种群数量调查分析

2005～2006年秋季,对黄兔尾鼠在新疆北坡经济带的分布区域新疆乌苏和沙湾的主要牧场巴音沟牧场、博尔通古牧场的种群数量进行了调查。结果显示,乌苏巴音沟牧场黄兔尾鼠的种群数量2005年为0只/hm2,2006年为2只/hm2,沙湾博尔通古牧场的黄兔尾鼠的种群数量2005～2006年为0/hm2,两地的黄兔尾鼠的种群数量均处于较低水平。     

新疆啮齿动物新种新亚种新记录种与某些鼠种的新分布

本文报告了近 10余年新疆啮齿动物分类、分布的新发现。其中有新种伊犁鼠兔 ,新亚种天山黄鼠尼勒克亚种 ;新疆新记录种大林姬鼠、高原鼠兔、藏鼠兔、柯氏鼠兔 ;中国新记录种戈壁阿尔泰山鼠平和草原鼠兔。此外还指出脂尾三趾矮跳鼠、小毛足鼠、长尾仓鼠、大沙鼠、水鼠平和鼹形田鼠等 6种动物的新分布地点。     

同德牧场主要害鼠的分布及数量调查

同德牧场位于青海省同德县东北部巴滩地区,面积约为26万亩,其中耕地6万余亩。该区草场植被属高山草甸化草原类型,土壤以暗栗钙土为主。天然草场以针茅、苔草及早熟禾为健群种。唯牧场东北隅巴水以北地区牧场为半荒漠类型草原草场,植被健群种为芨芨草、狼毒等。此区历来鼠害严重,1964年曾使用飞机投散磷化锌毒饵法,对大规模灭杀达乌尔鼠兔(Ochotona daurica)(以下简称鼠兔),取得了良好的效果。此后七、八年间鼠兔的数量一直较低,1973年以后逐渐回升,在不少地块已接近或恢复     

新疆两种啮齿类动物的核型分析

本文以子午砂土鼠和草原兔尾鼠为材料,采用常规骨髓制片法制备染色体标本,对它们的核型进行了分析,其中子午砂土鼠和草原兔尾鼠分别为2n=50和2n=54,核型公式为:12(M)+14(SM)+22(A)和4(M)+4(ST)+44(A)。     

大隆(TALON)灭鼠的试验研究

作者于1980年3～4月和7～8月间,在青海省天峻县和门源县草甸草原牧场进行了新杀鼠剂大隆杀灭我国西北草原主要害鼠—高原鼠兔(Ochotonacurzoniae)、中华鼢鼠(Myospalax fontanieri kukunoriensis)的试验研究。大隆对鼠兔的LD_(50)为0.1380mg/kg(0.1192～0.1568mg/kg),对鼢鼠的LD_(50)为0.4388mg/kg(0.2742～0.7022mg/kg)。 0.015％、0.030％和0.060％三种浓度大隆毒饵对鼠兔的现场灭效均达90％以上。一系列试验证明,大隆对草原害鼠的毒力强,使用浓度低,适口性好,无明显的耐药性,对天敌的危害性小。作者认为大隆可以应用于草原灭鼠,并可能有较好的前景。     

不育技术控制长爪沙鼠种群的初步研究

长爪沙鼠对混合不育剂EP-1的摄食系数为0.87,适口性良好。在野外投饵试验中,其洞口密度和洞系密度比对照组下降,表明该药对长爪沙鼠有毒杀作用。成幼比从0.6∶1降至0.45∶1。表明该药控制长爪沙鼠繁殖的效果显著。本试验还对该药对长爪沙鼠的生理作用作了测试。     

Relative abundance of Bemisia tabaci Gennadius (Homoptera: Aleyrodidae) and its parasitoids,and the impact of augmentative release of Eretmocerus spp. (Hymenoptera: Aphelinidae) on the population dynamics of the pest in Burkina Faso (West Africa)

Whitefly infestations and parasitism were monitored year-round in overlapping cotton crops sown on three dates in Burkina Faso. The relative abundance of B. tabaci (Gennadius) and its parasitoids, Eretmocerus spp. and Encarsia spp., was recorded in control and insecticide-sprayed plots. Low B. tabaci populations developed during the first half of the rainy season. Pest populations increased when rainfall was ending, and the levels reached were higher in insecticide-treated plots (48 nymphs/leaf) than in control plots (25 nymphs/leaf). Parasitism reached 88.7% in control plots, and 53.7% in insecticide-treated plots. Eretmocerus spp. nymphs were more abundant than Encarsia spp. in both treated and control plots. A positive and significant curvilinear relationship was observed where % parasitism, on a linear scale, rose to a plateau with logarithmic increase in host density. In general % parasitism was correlated with the abundance of pest populations except in March and April where parasitism increased while B. tabaci populations decreased. In a separate experiment, adult Eretmocerus spp. were released into caged cotton plants to study the impact of augmentative releases of the parasites on the population dynamics of the pest. Pest densities increased from 1.47 nymphs/leaf to 39.4 nymphs/leaf in the control, but were reduced to 0.8 and 0.6 nymphs/leaf in the cages where, respectively, 4 and 8 parasitoids were released per plant. It appears that parasitism is an important factor reducing B. tabaci populations during and after the cotton-growing season, and that Eretmocerus spp. are promising biological control candidates against the pest in cotton.     

Effects of planting density and the composition of wheat cultivar mixtures on stripe rust: an analysis taking into account limits to the replication of controls

ABSTRACT The effect of plant density on disease is not well understood in populations of a single host plant genotype and has been studied even less in mixtures of host genotypes. We performed an experiment to evaluate the effect of wheat planting density on infection by Puccinia striiformis in experimental plots with a single wheat genotype and in plots with two genotypes making up a range of frequencies. Stripe rust severity in single-genotype plots increased with planting density in 1997 but decreased with planting density in 1998. Disease in host mixtures was compared to the weighted mean of disease levels in the corresponding single-genotype plots. The design of the field experiment included limited replication of these reference treatments (that is, there was not a unique pair of single-genotype plots for each mixture plot); therefore, we devised an analysis based on collapsing the data into independent mean observations. Disease reduction due to host diversity was less when one genotype predominated than when both host genotypes were present at nearly equal frequencies. The greatest mean host-diversity effect for reduced disease was at the intermediate planting density of 250 seeds per m(2).     

不同播种密度对地膜小麦重要农艺性状的影响

在天水地区大田设置6个播量水平，观测不同密度条件下地膜小麦群体重要农艺性状的变化规律，并与露地小麦相对照。结果表明：单株分蘖数、最高总茎数、基部节间长度是有规律的增加；地膜小麦的单株分蘖数、最高总茎数的变幅较小，而露地小麦的变幅较大；基部节间长度随密度的增加而增加，地膜小麦的增长较快；单位面积有效穗数、穗粒数、千粒重、单位面积上的产量均随密度的变化而变化，但地膜小麦的变幅较小，而露地小麦的交幅较大；叶面积指数、叶片功能期，地膜小麦和露地在密度交化过程中表现出相同的趋势；籽粒饱满指数随密度增加而降低，二者有相同的趋势。而粒叶比则露地小麦的变幅较大；倒伏程度以露地小麦的变幅较大。     

Fossorial Forms of the Water Vole,Arvicola terresths (L.), in Europe1

The species Arvicola terrestris (L.) comprises 2 main life types:an aquatic form which is more common, and a form with fossorial habits which is confined to continental Europe, from the Cantabric Cordilliera to the Carpathian Mountains. However, forms inhabiting a primary wet biotope and a secondary dry one occur in a large border zone in the north of the range of the fossorial form. The fossorial type lives underground in grassland and some types of crops. Very recently, the structure and the occupation of burrows of this subterranean rodent were studied, as well as its digging behaviour and rhythm of activity. The fossorial form of A. terrestris is very easily captured, which makes it possible to estimate its density and to follow population evolution. This microtine shows cyclic population fluctuations and, during outbreaks, causes severe damage to grassland, both by its burrowing activity and by consuming plants. In orchards, it gnaws root systems of fruit trees, mainly of apples. Damage is also serious in gardens and in horticultural crops, especially to plants with fleshy roots. This vole does not eat cereals and does not invade forests. Control methods generally used are surface treatment with organochlorine insecticides (banned in most countries), poisoning (but no efficacious toxic baits are available), fumigation of burrow systems and trapping. Taxonomic research is needed for a better understanding of the status of the different life types of A. terrestris. The biological, ecological and ethological characteristics of these forms must be defined in order to develop and test adequate control methods.     

Effects of humidity on the development of grapevine powdery mildew

ABSTRACT The effects of humidity on powdery mildew development on grape seedlings and the germination of Uncinula necator conidia in vitro were examined. Studies were conducted at an optimum temperature of 25 +/- 2 degrees C. Disease on foliage was markedly affected by humidity levels in the test range of 39 to 98% relative humidity (RH), corresponding to vapor pressure deficits (VPD) of 1,914 to 61 Pa. Incidence and severity increased with increasing humidity to an optimum near 85% RH, and then appeared to plateau or decrease marginally at higher values. Conidial density and chain length also were proportional to humidity, but were influenced less strongly. There was a strong, positive linear relationship between humidity level and frequency of conidium germination with RH treatments of 相似文献   

棕色田鼠种群预测预报研究

１９９２年４月￣１９９５年４月作者在河南灵宝程村黄土塬农作区对棕色田鼠种群数量进行了逐月调查。结果表明,春季３、４月份种群数量高,夏季７、８月份数量低,而秋季１０月份数量又高,然后又降低,呈典型的双峰型。在对棕色田鼠种群年龄结构、繁殖强度等研究的基础上,探讨了种群消长机理和种群调节因子。发现３个月前的成亚比、２个月前的繁殖强度、温度指数、降雨量指数分别和密度呈显著相关,用以上因子建立多元回归方程预     

Suppression of Rhizoctonia solani in potato fields. 1. Occurrence

A search was made forRhizoctonia solani-suppressive soils by establishing many small experimental plots, half of which were planted withRhizoctonia-infected seed potatoes and the other half with disinfected seed stock. The sclerotium index of the harvested tubers was compared witht that of the seed potatoes. In suppressive soils, the sclerotium index of the harvest is much lower than that of the seed potatoes. None of the plots on holocene marine soils (loamy sand, sandy loam, clay loam and clay) proved to be suppressive in 1978 and 1979. Only on pleistocene, slightly acid sandy soil suppressiveness was observed. In 1978, four out of twelve plots showed suppressiveness when the plots were planted with seed potatoes produced on a sandy soil. In 1979, only two out of thirtyone plots were slightly suppressive when planted with seed potatoes produced on a young clay loam from a new polder. A higher percentage of sclerotia on tubers from sandy soils proved to be infected with antagonistic fungi (73%) than of those on tubers from marine clay or loam soils (25%). Factors that influence suppressiveness are suggested.     

Effects of quinestrol and levonorgestrel on populations of plateau pikas, Ochotona curzoniae, in the Qinghai-Tibetan Plateau

BACKGROUND: Plateau pikas ( Ochotona curzoniae , Hodgson, 1858) are viewed as a pest in the Tibetan Plateau meadow ecosystem when their population densities are high. Traditional culling using rodenticides often poses a high risk to non‐target species and even to humans. In this study, an investigation was made of the infertility effects of quinestrol (E), levonorgestrel (P) and a combination of the two (EP, ratio E:P = 1:2) on plateau pikas during 2007 and 2008. RESULTS: Treatment with E or EP significantly decreased the pregnancy rate of female pikas in 2007. In 2008, there was a cross‐year effect that still suppressed male reproduction in treated groups. Treatment with E obviously reduced the reproduction of pikas but not their population abundance in 2007; the reduction in population size was significant in 2008. CONCLUSIONS: Single baiting of quinestrol in early breeding season reduced the reproduction and population size of pikas throughout 2007. The effect of infertility lasted into the next breeding season through a cross‐year effect, which resulted in a significant reduction of population size in 2008. Quinestrol is a very promising non‐lethal approach to managing pika populations; however, several factors need to be investigated further to improve the practicality of this method. Copyright © 2012 Society of Chemical Industry     

放牧与封育对沙质草地植被特征及其空间变异性的影响

采用经典统计和地统计学的方法,定量分析了放牧与封育沙质草地植被盖度、丰富度、平均高度、密度和Shannon-Wiener指数的变化及其对植被空间结构特征的影响。结果表明:封育沙质草地植被盖度、平均高度和Shannon-Wiener指数显著大于放牧草地(P<0.01),但两者丰富度变化不显著(P>0.05)。封育草地与放牧草地植被盖度、丰富度和Shannon-Wiener指数的变异系数分别为14.3%,24.4%,13.5%和17.8%,25.7%,21.7%,前者小于后者。在本研究尺度上,封育沙质草地植被盖度以及封育与放牧草地植被密度的空间变异规律均能较好地拟合成球状模型,封育沙质草地植被丰富度和Shannon-Wiener指数以及放牧草地植被盖度、丰富度和Shannon-Wie-ner指数的空间变异规律均能较好地拟合成指数模型。封育与放牧草地植被盖度、丰富度、密度和Shannon-Wiener指数的空间自相关度C/(Co C)分别为70.7%,56.5%,51.0%,68.7%和50.1%,73.3%,70.0%,68.9%,表明封育与放牧草地各变量均具有中等的空间相关性。封育草地所有变量半方差函数值均小于放牧草地。封育草地和放牧草地的植被盖度、丰富度、Shannon-Wiener指数变程分别是36.73 m,85.02 m,161.91 m和24.98 m,5.64 m,51.78m,前者大于后者。放牧草地植被的空间变异性强、破碎化程度高,封育草地植被的空间依赖性强、变异性弱。