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1.
兽类的死亡率   总被引:3,自引:0,他引:3  
张知彬 《动物学报》1994,40(2):137-142
本文共收集了33种兽类的年均死亡率数据。求得陆生兽类的死亡率和体重的回归模型为: Dt=0.695-0.0973ln Wt(r2=0.865,p<0.001) Dh=0.732-0.100ln Wh(r2=0.891,p<0.001) Dc=0.619-0.0908ln Wc(r2=0.869,p<0.001)这里,Dt、Dh和 Dc分别为陆生兽类、食植兽类和食肉兽类的年均死亡率;Wt、Wh和 Wc则分别是它们的体重(公斤)。研究发现:陆生兽类的体重决定了年均死亡率86%以上的变异:食肉兽类比同样体重的食植兽类的年均死亡率小;飞行兽类比同样体重的陆生兽类的年均死亡率小。兽类死亡率的这一变异规律被认为和能量限制有关。  相似文献   

2.
蒋高明 《生态学报》1995,15(4):407-412
本文分析了承德市油松(PinustabutaeformisCarr.)针叶硫和重金属含量变化及其与大气SO_2浓度之间的相关性,探讨了油松针叶对大气SO_2的生物监测作用,结果认为:植物S含量生长末期>休眠期>生长初期>生长旺盛期(p<0.001);重金属中Pb表现为类似的规律,S和Pb含量分别从0.75mg·g ̄(-1)和0.7μg·g ̄(-1)上升到1.58mg·g ̄(-1)和2.0μg·g ̄(-1)。Ni变化不明显;Zn、Cu和Fe呈下降趋势,但Zn在休眠期略有回升。Mn在休眠期最高,但生长期也很高,其余季节相对较低。这种变化特点与大气中SO_2和总悬浮颗植物(TSP)的变化趋势基本一致;油松针叶S含量与大气SO_2浓度之间具有很显著的相关性,其中火车站监测点生长季节相关公式Y=-0.0263+0.0965X(r=0.8911,p<0.001);城区Y=0.0126+0.0618X(r=0.7841,p<0.01)。利用后者可对整个承德市区的大气SO_2污染状况进行生物监测。  相似文献   

3.
黑鲷的胃排空率   总被引:12,自引:0,他引:12  
在实验室内,18℃条件下测量了体重在20-40g的黑鲷的胃排空率,并用3种数学模型拟合了黑鲷的排空率,结果表明,3种模型都能很好地拟合实验数据,但通过统计学分析发现不论是用湿重还是用于重表示胃含物,线性模型都拟合得最好。用湿重表示时模型为Y=1.14-0.06t(r^2=0.82,p〈0.001);而用干重表示时模型为Y=1.36-0.07T(r^2=0.62,p〈0.001),实验还得出体重20  相似文献   

4.
小兴安岭凉水自然保护区蝶类多样性   总被引:5,自引:0,他引:5  
顾伟  马玲  刘哲强  焦玥  王利东  张琛  孙虎  孙美欧 《生态学报》2015,35(22):7387-7396
2012—2013年选取原始阔叶红松林、人工林、天然次生林和灌丛草甸4种典型植被生境,对小兴安岭凉水自然保护区的蝶类进行了系统研究。共捕获蝶类1438头,分属7科47属76种,4种植被生境中蝶类群落优势类群均为蛱蝶科,不同生境蝶类群落相似性与生境植被类型密切相关。计算分析了4种植被生境中蝶类多样性指数、物种丰富度、优势度指数、均匀度指数和种-多度关系,结果表明:3种森林生境蝶类多样性大于灌丛草甸,原始阔叶红松林蝶类具有最高的多样性指数、较高的物种丰富度、均匀度指数以及最低的优势度指数,种-多度分布为对数正态分布,说明环境质量优越,最适合蝶类生存和繁衍;灌丛草甸蝶类的多样性指数、物种丰富度和均匀度指数均为最低,而优势度指数最高,种-多度分布为对数级数分布,反映植物群落结构较单一,适合各种蝶类生存和繁衍的资源不足;天然次生林蝶类多样性指数、物种丰富度高于人工林,均匀度小于人工林,但前者种-多度分布为对数级数模型,后者为对数正态模型,说明在封山育林状态下,对森林植被组成进行适当合理的干扰,有利于森林的健康发展  相似文献   

5.
采用定点法、样线法和随机调查法,2005—2008年间对安徽鹞落坪国家级自然保护区蝶类垂直分布及群落多样性进行调查.本次调查共捕获蝶类3681只,隶属于10科69属111种,其中蛱蝶科的物种数、个体数和多样性指数均高于其他各科;该地区蝶类呈现由东洋界向古北界过渡的特征,且随着海拔的升高东洋界种类逐渐递减,古北界种类逐渐增多.在3个垂直带中(海拔低于800 m、800~1200 m、高于1200 m),海拔800~1200 m垂直带的蝶类种类最丰富.研究区6种主要生境类型(落叶阔叶林、常绿针叶林、针阔混交林、灌木和次生林、农田、居民点)中,灌木和次生林中蝶类的物种数和个体数量、物种多样性指数均高于其他各生境类型,农田生境中蝶类多样性指数最低;生境之间蝶类物种的相似性系数主要与生境构成要素中的植被类型有关,植被类型相差越大,蝶类物种的相似性系数就越小,研究区针阔混交林与灌木和次生林之间的蝶类物种相似性系数最高(0.61),而常绿针叶林与灌木和次生林之间的相似性系数最低(0.20).  相似文献   

6.
鹿回头库礁造礁石珊瑚物种多样性的研究   总被引:3,自引:2,他引:1       下载免费PDF全文
于登攀  邹仁林 《生态学报》1996,16(5):469-475
定量分析鹿回头岸礁造礁石珊瑚群落的种类组成,选择α-多样性和β-多样性的度量方法,分析了该群落造礁石珊瑚种、属和科的多样性及其与所处生境的关系。结果表明:鹿回头岸礁造礁石珊瑚群落的物种比较丰富,多样性和均匀度指数都较高,但在不同地段之间存在着明显的差异。水深中等的地段(2.4~5.0m)的多样性指数高于较浅(1.5~2.0m)和较深(5.5~6.5m)地段;期间带与潮下带之间和礁平台与向海斜坡之间的两个过渡地带的生境条件复杂,物种多样性和种类分布的混杂程度都高于其他地段。  相似文献   

7.
青海祁连地区不同生境类型蝶类多样性研究   总被引:47,自引:4,他引:43  
于1997-1999年对青海祁连地区不同生境类型中蝴蝶多样性进行了研究。研究中依据海拔高度、气候、土壤和植被的不同将该地区的蝴蝶生境划分为5种类型:山缘农田、山地草原、森林草原、高寒灌丛草甸、裸岩。共收集蝴蝶4367只,隶属于6科35属53种,计算了5种生境类型中蝶类物种丰富度、相似性系数、多样性指数,其中,蝶类物种丰富度由小到大的顺序为:裸岩(6种)<山地草原(13种)<森林草原(14种)<高寒灌丛草甸(22种)<山缘农田(H′=2.7071)、高寒灌丛草甸(H′=2.7734);森林草原和山缘农田的相似性系数最高(0.3704),其次为山地草原和高寒灌丛草甸(0.2500,裸岩与其他生境类型的相似性系数最低。  相似文献   

8.
运用模糊聚类方法,探讨豫西农作区鼠类群落分类及其与农田斑块生境的关系,比较百分率相似系数(PS)、相关系数(r)和夹角余弦(Cos)3种相似指标。发现r的聚类结果与农田斑块生境具显著的相依性(P<0.025)。故将该地鼠类群落划分为棕色田鼠+大仓鼠亚群落及大仓鼠+棕色田鼠亚群落。同时,比较2个亚群落的物种数、多度和多样性Shannon指数的差异.  相似文献   

9.
应用SABC免疫组织化学方法研究67例胃标本中p53和c-myc的表达与多药耐药性(MDR)的关系。结果显示本组胃癌中p53阳性32例,阳性率47.8%;c-myc阳性37例,阳性率55.2%;P-gp阳性39例,阳性率58.2%。p53的异常表达与mdr-1基因表达呈显著正相关(r=0.63,P<0.05),而c-myc和mdr-1的表达无明显相关。提示p53异常表达可增加mdr-1基因的表达,从而使胃癌细胞获得MDR表型  相似文献   

10.
本文应用高电压、低输出阻抗刺激器,经皮给予人大脑皮层和脊髓电刺激,同时在上肢鱼际和下肢胫骨前肌记录诱发肌肉动作电位,并测定其刺激大脑皮层所诱发反应的潜伏期-皮层潜伏期、刺激脊髓所诱发反应的潜伏期-脊髓潜伏期。结果表明:皮层潜伏期(Lcor.)和脊髓潜伏期(Lsp.)与身高呈正相关,相关系数是:鱼际:rLcor.=0.208,p<0.05(v=114),rLsp.=0.364,p<0.01(v=114);胫骨前肌:rLcor.=0.349,p<0.01(v=69),rLsp.=0.317,p<0.01,(v=69)。回归方程是:鱼际:Lcor.(ms)=12.148+0.046H(cm),Lsp.(ms)=2.085+0.065H(cm);胫骨前肌:Lcor.(ms)=13.038+0.097H(cm),Lsp.(ms)=3.397+0.078H(cm)。这样在临床工作中,只要测量出身高,就可以确定其各肌肉的皮层潜伏期、脊髓潜伏期的正常值,它将给临床工作带来方便,同时它也将给临床中枢神经疾病的诊断和预后判定提供方便。  相似文献   

11.
Ten accessions of seed of the genus Limnanthes, representing seven species and their varieties, were tested for germination at temperatures of 40°, 50°, 60°, 70° F, and at room temperature varying from 72°–78° F. Four of the ten accessions germinated best at 40°, three at 50°, and three at 60° F. Germination was relatively poor at 70° F and almost zero at room temperature. The total germination averaged over all accessions was about the same for both 40° F and 50° F, slightly less for 60° F. Seeds at 60° F reached a peak in germination rate in four days; those at 50° F required six days; those at 40° F required 11 days. Seeds, started at room temperature and moved to 50° F 15 days later, attained only about half the total germination of a similar group of seeds originlly started at 50° F. Some of the species tested germinated almost equally well at 40°, 50°, or 60° F; others germinated best only at, or near, one of these temperatures. Substantially all of the seeds that germinated over a period of 50 days did so in less than 30 days; most of these germinated in the first 14 days.  相似文献   

12.
In vivo protein synthesis in barley (Hordeum vulgare L.) hypocotyl was maximum at 35°C and 40°C.HPLC analysis of soluble proteins showed 10 different types of proteins, out of which the peak corresponding to retention time 13.3 min was present at 25°C but was absent at 35°C and 40°C. Instead, another peak with retention time 13.7 min was noticed at 35°C and 40°C. Amino acid analysis showed that heat shock resulted in an increase in lysine and histidine and decrease in arginine. Heat shock also resulted in increase in peroxidase, protease and ribonuclease activity at 35°C and 37°C in comparison to 25°C. The incorporation of (3H)-uridine was significantly decreased at 37°C in comparison to 25°C.  相似文献   

13.
We evaluated the effect of global warming on Araucaria angustifolia (Bert.) O. Kuntze, a critically endangered native tree of Southern Brazil, by studying the effects of short‐term high temperature treatment on cell viability, respiration and DNA repair of embryogenic cells. Compared with control cells grown at 25°C, cell viability was reduced by 40% after incubation at 30 and 37°C for 24 and 6 h, respectively, while 2 h at 40 and 42°C killed 95% of the cells. Cell respiration was unaffected at 30–37°C, but dramatically reduced after 2 h at 42°C. The in vitro activity of enzymes of the base excision repair (BER) pathway was determined. Apurinic/apyrimidine endonuclease, measured in extracts from cells incubated for 2 h at 42°C, was completely inactivated while lower temperatures had no effect. The activities of three enzymes of the mitochondrial BER pathway were measured after 30‐min preincubation of isolated mitochondria at 25–40°C and one of them, uracil glycosylase, was completely inhibited at 40°C. We conclude that cell viability, respiration and DNA repair have different temperature sensitivities between 25 and 37°C, and that they are all very sensitive to 40 or 42°C. Thus, A. angustifolia will likely be vulnerable to the short‐term high temperature events associated with global warming.  相似文献   

14.
Cucumber mosaic (CMV) and alfalfa mosaic (AlfMV) viruses could not be detected in Nicotiana rustica tissues cultured at 32 °C for 16–18 days or at 40 °C for 5 days, but infectivity remained high in comparable tissue cultured at 22 °C. Incubation of infected cultures at 28–30 °C resulted in an initial reduction followed by a partial recovery in the infectivity of both viruses. The infectivity of CMV in tissues grown between 12 and 32 °C was highest in cultures grown at 12 °C. Although CMV infectivity was not detected in cultures after 16–18 days at 32 °C, virus was eliminated only after a further 30 days at 32 °C. When cultures were transferred from 32 to 22 °C after shorter treatment periods, infectivity rapidly increased to levels higher than those of infected tissues grown continuously at 22 °C. At 40 °C, CMV was eliminated from infected tissues after 9 days and AlfMV after 7 days. Cultures grown continuously at 40 °C deteriorated rapidly but, when grown under diurnal alternating periods of 8 h at 40 °C and 16 h at 22 °C, they remained viable and CMV was also inactivated.  相似文献   

15.
C. Stenseth 《BioControl》1979,24(3):311-317
The development ofPhytoseiulus persimilis Athias-Henriot and the effectiveness of it as a predator ofTetranychus urticae (Koch) were studied at constant temperatures of 15°, 18°, 21°, 24° and 27°C (humidity fluctuations from 60% to 90% R.H.) and at constant humidities of 40% and 80% R.H. at the temperatures 21° and 27°. Optimal temperature for time of development was 27° (at 60%–85% R.H.). A high reduction in egg vitality was recorded at 40% R. H. and 27% At 21° the egg vitality was only slightly lower at 40% R.H. than at 80% R.H. The predator gave control ofT. urticae at temperatures from 15° to 27° (humidity fluctuation from 60%–90% R.H.), and the most rapid and efficient control was obtained at 27° (60%–85% R.H.). The predator did not give sufficient control ofT. urticae at 27° and 40% R.H. At 21° control ofT. urticae was obtained at both 40% and 80% R.H., but the prey population was reduced faster at 80% R.H. than at 40% R.H.  相似文献   

16.
Prosopis chilensis is a plant highly tolerant to heat shock   总被引:1,自引:0,他引:1  
At temperatures between 25 and 35°C, 100% of Prosopis chilensis seeds germinated within 24 h. At higher temperatures, the germination rate was reduced; at 50°C, seeds did not germinate. After germination at 25°C, the optimal temperature for seedling growth was 35°C and the seedlings did not grow at a temperature of 50°C. However, when germination was at 35°C, the optimal temperature for seedling growth was 40°C and some seedlings grew at 50°C, suggesting that thermotolerance was induced during seed germination at 35°C. Further thermotolerance can be induced in seedlings germinated at 35°C, by exposing them to 40°C for 2h. Under these conditions, seedlings exhibited increased growth rate at 45 and 50°C. Fluorography of SDS-polyacrylamide gel electrophoresis of the proteins synthesized and accumulated during 2 h at temperatures of 35, 40, 45 and 50°C in the presence of [35S]methionine revealed the expression of 11 proteins not detectable at 35°C. Most of the proteins present at 35°C also increased in expression. The temperature for maximal expression of these proteins was 45°C.  相似文献   

17.
黄土丘陵区坡改梯生态经济耦合效应   总被引:3,自引:1,他引:2  
徐勇  党丽娟  汤青  高雅 《生态学报》2015,35(4):1258-1266
坡改梯是黄土丘陵区提高农作物单产和控制水土流失的有效措施。基于坡改梯内生和外延效应的学术思路,构建了能定量刻画坡改梯生态经济耦合状况的数学模型;以位于黄土丘陵区腹地的延安燕沟流域为例,利用土地利用和数字地形等空间数据、作物产量和土壤侵蚀模拟数据以及监测和调查数据,定量评价分析了燕沟流域坡改梯的生态经济耦合效应。结果表明:地形坡度越大,坡改梯的生态经济耦合效应越显著;地形坡度5°和15°是两个重要阈值,5°以下不必进行坡改梯,5°—15°之间应作为坡改梯的重点对象,15°以上宜退耕还林还草。坡改梯使燕沟流域农耕地的生态经济耦合程度得到了显著提高,坡改梯前生态经济耦合指数为1.805t/100元,坡改梯后下降为0.853t/100元,下降幅度达52.73%。随着坡改梯和植被覆盖率的提高,流域的洪水径流量和输沙模数均大幅度下降。  相似文献   

18.
Supraoptimal Temperature Effects upon Agrostis palustris   总被引:1,自引:0,他引:1  
Agrostis palustris turfs cut weekly at 1.3 cm were subjected to successive four-week periods with day-night temperature regimes of 20–10, 25–15, 30–20, 35–25 and 40–30°C. Plants grown at 40–30°C exhibited a growth character distinctly different from those grown at 20–10°C. They were more upright and bristle-like in growth habit. The percentage dry weight of leaf blade tissue increased 67% and weight per unit area increased 53% between 20–10 and 40–30°C. Reduced leaf blade width was noted first at 30–20°C while leaf blade length reduction first occurred at 35–25°C. Weekly yields were significantly reduced at the supraoptimal temperature regimes of 35–25 and 40–30°C. Chlorophyll content was lowest at 20–10 and 40–30°C, the lowest and highest temperature regimes studied. Shoot density appeared to decrease under the 35–25°C regime, but no dead plants were observed. The apparent decrease in shoot density was attributed to the upright growth habit. Density decreased at 40–30°C upon death of individual plants. A community of grass plants maintained as a turf was found to change in form quite rapidly in response to temperature.  相似文献   

19.
In a two-phase operation, E. coli containing λSNNU1 (Q S ) in the chromosome is typically cultured at 33°C and cloned gene expression is induced by elevating the temperature. At least 40°C is necessary for complete induction of cloned gene expression; however, temperatures above 40°C have been shown to inhibit cloned gene expression. This suggests that a three-phase operation, which has an induction phase between the growth and production phases, may result in higher gene expression. In this study, optimal temperature management strategies were investigated for the three-phase operation of cloned gene expression in thermally inducible E. coli/bacteriophage systems. The optimal temperature for the induction phase was determined to be 40°C. When the temperature of the production stage was 33°C, the optimal time period for the induction phase at 40°C was determined to be 60 min. In contrast, when the temperature of the production phase was 37°C, the optimal period for the induction phase at 40°C was 20∼30 min. When the three-phase temperature and temporal profile were set at a growth phase of 33°C, an induction phase at 40°C for 30 min, and a production phase at 37°C, the highest level of cloned gene expression was achieved.  相似文献   

20.
实验在8只大棕蝠(Eptesicusfuscus)上进行.选取了5个声源方位记录部位对侧80°(C-80°)、40°(C-40°)、0°和同侧40°(I-40°)、80°(I-80°).下丘听神经元的频率调谐曲线的形状有三种V型、封闭型和U型.以C-40°的频率调谐曲线为对照,声源方位改变时,多数神经元频率调谐曲线的形状和最佳频率不变.多数神经元在声源方位由记录部位对侧转向同侧时,频率调谐曲线的锐度(以QndB值为指标)由小变大;神经元在I-80°、I-40°的QndB值显著高于C-80°、C-40°、0°的QndB值.在所观察的47个神经元中,5个声源方位的最低阈值的平均值有显著差异,由高到低的分布为MTI-80°>MTI-40°>MT0°>MTc-80°>MTc-40°.我们推测,声源方位对神经元频率调谐特性影响的机制,可能是抑制性和兴奋性输入的比例不同而相互整合的结果.  相似文献   

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