石龙子的猎物选择研究

分析了石龙子（Eumeces chinensis)自然条件下的春季食性，实验研究石龙子的猎物选择及其捕食量摄入率。结果表明，石龙子在晚春的主要猎物组成为腹足纲螺类及鞘翅目昆虫，大小在11－20mm的猎物出现频次最高。石龙子在6种实验猎物中更偏爱捕食鞘鞘翅目成虫及鳞翅目成虫，对猎物种类存在选择性；而且，石龙子在同一种类不同大小的猎物间更多地捕食体长在11－20mm的个体，对猎物的大小同样存在选择性，通过进一步测量石龙子捕食不同猎物种类及不同大小猎物的摄食时间来分析捕食能量摄入率，获知石龙子有选择地捕食猎物种类及猎物大小有利于提高捕食能量摄入率，符合最佳摄食理论。     

小兴安岭地区大型偶蹄类植物性可食资源质量的研究

从食物链的角度来评价小兴安岭地区东北虎（Ｐａｎｔｈｅｒａｔｉｇｒｉｓａｌｔａｉｃａ）猎物的不同类别植物性可食资源品 质的季节变化与所在生态系统的影响．６类植物性可食资源（灌木叶、灌木茎、蕨类、苔草、其他草本和根）样品分春、夏、 秋３季分别采自随机分布于５种森林类型的样方．比较不同林型、季节及不同类别植物性可 食 资 源 的 粗 蛋 白、粗纤维含 量,得到这些植物性可食资源品质在不同森林生态系统中的分布和季节变化特点．研究发现:１）植物性可食资源的粗蛋 白含量在不同森林类型、不同季节以及食物类别之间有显著差异,其中灌木叶、蕨类是粗蛋白含量最高植物性可食资源, 且春季植物性可食资源粗蛋白平均含量最高,３个红松阔叶林型的可食资源粗蛋白平均含量最高;２）植物性可食资源的 粗纤维含量仅在不同可食资源类别间差异显著,而季节与森林类型间差异不显著．在６类可食性资源中,灌木茎的粗纤 维含量最高;灌木叶、蕨类粗纤维含量低且粗蛋白含量高而品质最高．      

陕西省歧山地区纵纹腹小鸮的食性研究

文章报道了纵纹腹小鸮在陕西省,歧山县京当地区的捕食行为及其在不同季节的食性变化.它在冬季(1—2月)主要活动于晚上.繁殖期活动时间延长,并越来越接近昼行性.在食物组成上,也有明显的季节性和地区性差异.冬季在取食频次上以鼠类为主,占整个猎物出现频次的66.7%(其中大仓鼠Cricetulus triton占25.6%),昆虫类仅占20.5%;繁殖前期(3—5月)鼠类占34.5%,昆虫类 62%;繁殖后期(6一8月)食鼠占2.47%;食昆虫占96,9%.在同一生境内,它与大型鸮类——雕鸮BuboO bubo的营养生态位发生部分重叠(重叠指数C为0.324),只是前者偏食小型鼠类和昆虫,而后者们食大、中型啮齿类.在不同地区和生境下表现出与地区的食源丰富程度有关.在饲养过程中,发现它取食一些植物果实,剖胃时也发现胃内偶有植物枝叶,同时,我们还观察到,小鸮在野外或饲养情况下,有食同类尸体的现象,但并未发现其活体相残.     

无集团外猎物情况下棉蚜捕食者之间的集团内捕食水平特征

集团内捕食作用是一种更为复杂的种间关系,广泛存在于各类生态系统中。为明确棉蚜捕食性天敌之间集团内捕食水平与个体发育阶段的关系,观察了大草蛉,七星瓢虫与多异瓢虫不同虫态之间40个处理组合的集团内捕食水平。在温室盆栽棉花(无蚜虫)上接种等量的试虫,观察24 h后的存活数量。结果表明,当参与双方的虫态不同时,出现不对称捕食,高一虫态处于优势;当参与双方的幼虫龄期不同时,高龄幼虫的存活数量显著大于低龄幼虫,呈现单向捕食;成虫对卵、1龄和4龄幼虫的捕食程度随虫龄增大而呈抛物线增长,存在显著的二次函数关系。本研究结果说明,在没有集团外猎物(蚜虫)存在的情况下,当广谱捕食性天敌大草蛉、七星瓢虫与多异瓢虫之间的集团内捕食水平在参与者的虫态或虫龄不同时,集团内捕食水平与双方发育阶段有关;当参与者虫态或虫龄相同时,取决于物种生物学特性。     

毒隐翅虫研究进展：3 食性及其在农业上的重要意义

本文综述了毒隐翅虫的食性及其在农业上的重要性。据研究,梭毒隐翅虫成虫为多食性,主要以昆虫、螨类和土壤线虫为食,也以腐植质为食;幼虫主要为肉食性,但在实验宣能在牛肉和黄瓜上喂养。许多报道涉及梭毒隐翅虫和艾毒隐翅虫大发生时作为害虫天敌的重要意义。     

虎纹蛙的食性与捕食行为的研究

通过养殖试验与野外观察相结合，研究了虎纹蛙（Hoplobatrachus rugulosa）的蝌蚪与成体的食性及捕食行为。结果表明，虎纹蛙是一种性凶猛的蛙类，喜食活的动物性食物，并具有互相残食的习性；在一定条件下，可取食不活动的食物；其捕食行为依蛙体与食物的相对位置而变化。     

肩斑银鳞蛛Leucauge blanda的捕食行为

蜘蛛的捕食行为,是直接影响捕食害虫效果的主要因子之一,也是人们选择有效的昆虫天敌的关键。本文记述了在自然条件下,肩斑银鳞蛛(肖蛸科Tetragnathidae银鳞蛛属Leucauge)的捕食行为。猎物以蚜虫、蚊子等小型昆虫为主,捕获手段多采用抓-拖出的原始方式;而对中、大型猎物则采用、咬、包裹等多种手段。捕食高峰多出现在早晨和傍晚。在捕食行为的进化上,尚处于从原始阶段到高级阶段之间的一个中间过渡阶段。     

贵州疣螈夏季生态研究

本文报道了贵州疣螈夏季栖息环境、活动习性、繁殖及食性与捕食行为。贵州疣螈主要以昆虫纲的种类为食，有益系数达５２．３１％，是一种对农林业有益的动物。     

昆虫取食常绿阔叶林木荷叶片的空间变化

植物叶虫食的空间变化同生境有关,能反映昆虫与植物的相互关系.为探讨不同生境植物的叶虫食情况,以木荷林林下、林窗以及竹林林下3种不同条件下木荷幼树为研究对象,观测了其叶虫食损失率与叶虫食频率,并分析了观测结果产生变化的可能原因.结果表明:木荷林林下木荷幼树叶片的叶虫食损失率(14.14%)显著高于竹林林下(5.71%),木荷林林下(12.28%)低于木荷林林窗(14.72%),但差异不显著;大部分受损叶片其叶虫食损失率低于10%,昆虫对叶片仅为适量取食,叶面积大量损失的情况较少;木荷幼树叶虫食频率与叶虫食损失率极显著正相关.本研究发现昆虫取食叶片的行为随空间的变化而存在较大差异.     

星豹蛛对棉花害虫的捕食效应研究

研究了星豹蛛对棉花害虫的捕食效应．观察结果表明：星豹蛛对棉蚜、叶螨、棉铃虫、棉盲蝽的种群数量具有明显的控制作用．田间种群数量消长与棉花害虫密度表现为动态正相关（ｒ＝０．６１２４～０．８９２８）．在试验条件下，其功能反应表现为随猎物密度的增加捕食量增大，随自身密度的增加捕食量减少．用Ｈｏｌｉｎｇ－Ⅱ型反应模型Ｎａ＝ａ′ＴＮｔ／（１＋ａ′ＴｎＮｔ）能较好地拟合．星豹蛛对四种猎物的日最大捕食量依次为７１．４，１５８．７，１７．８，２５．０头．在蚜螨猎物共存时，星豹蛛的选食作用较小，选择系数Ｅ＝０．９８９６     

Harmonic-hopping in Wallacea's bats

Evolutionary divergence between species is facilitated by ecological shifts, and divergence is particularly rapid when such shifts also promote assortative mating. Horseshoe bats are a diverse Old World family (Rhinolophidae) that have undergone a rapid radiation in the past 5 million years. These insectivorous bats use a predominantly pure-tone echolocation call matched to an auditory fovea (an over-representation of the pure-tone frequency in the cochlea and inferior colliculus) to detect the minute changes in echo amplitude and frequency generated when an insect flutters its wings. The emitted signal is the accentuated second harmonic of a series in which the fundamental and remaining harmonics are filtered out. Here we show that three distinct, sympatric size morphs of the large-eared horseshoe bat (Rhinolophus philippinensis) echolocate at different harmonics of the same fundamental frequency. These morphs have undergone recent genetic divergence, and this process has occurred in parallel more than once. We suggest that switching harmonics creates a discontinuity in the bats' perception of available prey that can initiate disruptive selection. Moreover, because call frequency in horseshoe bats has a dual function in resource acquisition and communication, ecological selection on frequency might lead to assortative mating and ultimately reproductive isolation and speciation, regardless of external barriers to gene flow.     

Effect of acoustic clutter on prey detection by bats.

Bats that capture animal prey from substrates often emit characteristic echolocation calls that are short-duration, frequency-modulated (FM) and broadband. Such calls seem to be suited to locating prey in uncluttered habitats, including flying prey, but may be less effective for finding prey among cluttered backgrounds because echoes reflecting from the substrate mask the acoustic signature of prey. Perhaps these call designs serve primarily for spatial orientation. Furthermore, it has been unclear whether the acoustic image conveyed by FM echoes enables fine texture discrimination, or whether gleaning bats that forage in echo-cluttering environments must locate prey by using other cues, such as prey-generated sounds. Here we show that two species of insectivorous gleaning bats perform badly when compelled to detect silent and immobile prey in clutter, but are very efficient at capturing noisy prey items among highly cluttered backgrounds, and both dead or live prey in uncluttered habitats. These findings suggest that the short, broadband FM echolocation calls associated with gleaning bats are not adapted to detecting prey in clutter.     

不同土地利用类型土壤动物对土壤氮矿化季节变化的影响

以苏北沿海地区3种土地利用类型(杨树人工林、农田、杨农复合林)为研究对象,通过设置不同驱除土壤动物处理(撒萘驱除所有土壤动物、撒噻唑磷驱除土壤线虫、未驱除即对照),采用顶盖埋管法测定土壤矿质N含量及净N矿化速率,研究土壤动物对N矿化季节变化的影响。结果表明:①不同土地利用类型土壤NH⁺₄-N、NO^-₃-N、土壤总矿化N(TMN)含量均呈显著的季节变化(P＜0.05),驱除线虫和所有土壤动物显著降低了不同季节的土壤NH⁺₄-N、NO^-₃-N和TMN含量,但并没有改变它们的季节变化基本趋势。3种土地利用类型土壤NH⁺₄-N含量的季节变化均表现为夏＞秋＞春＞冬; 对于NO^-₃-N和TMN含量的季节变化,杨树林和杨农复合林均表现为夏＞秋＞春＞冬,而农田则表现为秋＞夏＞春＞冬; ②不同土地利用类型净N矿化速率季节差异显著(P＜0.05),杨树林和农田的净N矿化速率最大值出现在秋季(分别为0.25、0.29 mg/(kg·d)),杨农复合林净N矿化速率最大值出现在夏季(0.45 mg/(kg·d))。驱除线虫和驱除所有土壤动物显著降低了所有土壤利用类型春、夏、秋季的土壤净N矿化速率(P＜0.05),而未改变杨农复合林净N矿化速率的季节变化趋势。驱除所有土壤动物改变了杨树林和农田的净N矿化速率的季节变化趋势,杨树林和农田驱除所有土壤动物的季节变化表现为夏＞秋＞春＞冬,而对照表现为秋＞夏＞春＞冬。重复测量方差分析表明,季节和驱除土壤动物处理对净N矿化速率有显著的交互作用(P＜0.01),表明驱除土壤动物可能会影响净N矿化速率的季节变化。     

Diets, eco-environments and seasonal variations recorded in the oxygen and carbon isotopic compositions of mammal tooth enamel from the Shunshanji site, Sihong County, Jiangsu Province, China

The carbon and oxygen isotopic compositions of the tooth enamel of mammals, including deer, wild pigs, buffaloes and domesticated pigs from the Shunshanji site, Sihong County, Jiangsu Province, China, were analyzed to reconstruct the mammals’ ecoenvironments and diets, and to evaluate seasonal variations in the study area. Carbon isotopic compositions of buck samples revealed that the deer ate completely C₃ plants and the environments they inhabited were relatively open and that wild pigs ate primarily C₃ plants. Oxygen isotopic compositions indicated that the body sources of these two mammals were different, i.e. the deer and pigs lived in different niches within a relatively similar ecosystem. Modern domesticated pigs were isotopically more positive than the ancient wild pigs in carbon δ ¹³C values, suggesting the former ingested more C₃ plants relative to the latter. Although the δ ¹⁸O data showed modern domesticated and ancient pigs had similar oxygen isotope compositions, their water sources were different. The carbon and oxygen isotopic patterns of premolar microsamples of ancient and modern buffaloes indicated that the plants ingested by the ancient buffalo varied with seasonal shifts, but plants ingested by the modern buffalo were relatively constant. The eco-environment of the modern buffalo was more open, warmer and drier than eco-environment of the ancient buffalo, which may be the result of the deforestation and other human activities. Ancient and modern seasonal changes were clearly recorded in the isotopic patterns and the seasonal variation amplitudes of the ancient and modern eco-environments were similar.     

西双版纳热带次生林林窗热量传递初步研究

以西双版纳热带次生林林窗为研究对象，以实际观测为基础，探讨林窗及其不同方位边缘气一地温差的时空分布特征及变化规律．结果表明：在西双版纳由于区域性天气现象(雾)、太阳高度和林窗边缘树木的共同影响，形成不同季节、时间林窗区域气一地温差在时空分布上的明显差异——低值区的时空位移现象及空间不对称性，具体表现为林窗气一地温差最低区域不是出现在林窗中央而是林窗某一侧，而且出现随季节动态位移的现象；林窗内不同介质间(空气、地面)热量传递方向随季节的不同而异．这种“峰值动态位移现象”可能会影响不同时期物种的入侵、定居、繁殖，进而影响林窗物种的组成．     

福建省马尾松群体和个体遗传变异的研究

<正>马尾松是福建省最重要的用材树种。本文对马尾松的群体和个体的遗传变异进行分析研究, 目的在于发掘当地树种的遗传资源,科学地制定马尾松的遗传改良程序,以及为当前林业生产中种子调拨和建立采种基地等工作提供依据。 1979年,共采集种子样本73份,包括全国不同产地、省内不同林分,同一林分不同家系和不同海拔高度的林分。1980年,于洋口,官庄林场作苗期比较。观测项目有种子大小,重量、发育程度、苗木高度,地径。封顶率和其它性状。根据试验结果,本文对各种变异类型做出了评价,并对福建省内马尾松的遗传改良程序提出初步意见。     

不同季节中兰州鲇肌肉水解氨基酸

目的研究兰州鲇(Silurus lanzhouensis)肌肉中常规营养成分和不同季节中肌肉水解氨基酸的组成和含量。方法采用氨基酸自动分析仪测定肌肉中水解氨基酸。结果兰州鲇肌肉中含有18种氨基酸,组成和含量顺序未呈现出季节性变化特点;蛋氨酸、异亮氨酸、亮氨酸、天冬氨酸、丙氨酸这5种氨基酸的含量及氨基酸总量,均随季节的推移呈上升趋势,但在3个季节中仅有秋季显著高于春季(P<0.05);苏氨酸、丝氨酸和谷氨酸等9种氨基酸的含量和必需氨基酸总量等虽有季节性上升趋势,但在3个季节间均无显著差异(P>0.05);胱氨酸、组氨酸和精氨酸等4种氨基酸含量未呈现出季节性变化。结论兰州鲇是一种蛋白质含量较高的经济鱼类,肌肉中水解氨基酸的种类、含量顺序及多数氨基酸的含量在季节变化中有较大的保守性。     

华北地区动力和热力蒸发量特征研究

选用1957~2002年的气象观测资料,对华北地区5个分区动力和热力蒸发量的季节、年际变化规律,动力和热力蒸发量之间的差异,动力和热力蒸发量对总蒸发量的贡献以及近20年全球变暖背景下华北地区动力和热力蒸发量的变化趋势进行了分析.结果表明,华北各个区域动力和热力蒸发量的年、季变化规律有明显差异,动力蒸发量的季节变化呈双峰特征,而热力蒸发量则呈单峰变化.动力蒸发量和热力蒸发量的年和季节序列线性变化趋势有明显差异,在全球变暖的背景下,这种差异明显变大.年平均热力作用对总蒸发量的贡献大于动力作用,不同季节这种规律有所不同,温暖季节热力作用对总蒸发量贡献较大,寒冷季节动力作用大于热力作用(华北4区除外).     

Interannual precipitation variations in the mid-latitude Asia and their association with large-scale atmospheric circulation

This study analyzed the spatial differences of the precipitation variations in the mid-latitude Asia and their possible physical mechanisms during 1960–2009. The annual precipitation showed an opposite variations between the westerlies-dominated arid Central Asia (ACA) and monsoon-dominated North China (NC) during the study period. Given the different contributions of seasonal precipitation to annual total precipitation in ACA and NC, the atmospheric circulation anomalies during the major precipitation seasons (winter in ACA/summer in NC) were analyzed. In winter, negative North Atlantic Oscillation may cause negative height anomalies over the north side and positive anomalies over the south side of the ACA. Together, the enhanced pressure gradient and anomalous westerly wind brings more water vapor to ACA, and leaves less precipitation in NC. In summer, the low-pressure anomalies in Northeast China, along with a weaker summer monsoon and negative height anomalies in Eastern Europe together contribute to reduced (excessive) summer precipitation in NC (ACA). The interactions between ENSO and NAO may result in the opposite precipitation variations between ACA and NC. A significant 2–3-year cycle is identified in ACA, which is linked to the variations of westerly circulation in the middle troposphere.     

Sequences homologous to ZFY, a candidate human sex-determining gene, are autosomal in marsupials

Sexual differentiation in placental mammals results from the action of a testis-determining gene encoded by the Y chromosome. This gene causes the indifferent gonad to develop as a testis, thereby initiating a hormonal cascade which produces a male phenotype. Recently, a candidate for the testis-determining gene (ZFY, Y-borne zinc-finger protein) has been cloned. The ZFY probe detects a male-specific (Y-linked) sequence in DNA from a range of eutherian mammals, as well as an X-linked sequence (ZFX) which maps to the human X chromosome. In marsupials it is also the Y chromosome that seems to determine the fate of the gonad, but not all sexual dimorphisms. Using the ZFY probe we find, surprisingly, that the ZFY homologous sequences are not on either the X or the Y chromosome in marsupials, but map to the autosomes. This implies ZFY is not the primary sex-determining gene in marsupials. Either the genetic pathways of sex determination in marsupials and eutherians differ, or they are identical and ZFY is not the primary signal in human sex determination.