首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 93 毫秒
1.
牛背梁自然保护区(108°45′~109°04′E,33°47′~33°56′N)位于秦岭山脉东段,地跨秦岭南北坡。采用样线调查法和访问调查法,于2003年5月~2004年8月,对该保护区食肉动物及偶蹄动物的区系特征和生态分布进行了研究。该保护区共有18种食肉动物及偶蹄动物,其中属我国级、级重点保护动物的兽类分别有2种和7种。分析表明,保护区的有蹄类动物物种丰富,秦岭分布的有蹄类在该区域均有分布,但食肉动物种数仅占整个秦岭地区的45.5%。这些兽类中,属于东洋界的兽类有12种,占66.7%;属古北界的仅1种,占5.5%;其余5种为广布种,占27.8%。牛背梁保护区在动物地理区划上应属古北界和东洋界物种交汇的区域,且为东洋界逐渐向古北界过渡的区域。分析该区域食肉动物及偶蹄动物的生态分布发现,这些物种的垂直分布幅度有很大的差异。垂直分布幅度在海拔高差1300m以上、1000m左右、450~700m之间的物种各占1/3。结果还表明,区内这些兽类物种的丰富度随海拔的升高具有先升后降的垂直变化规律。不论是秦岭南坡还是北坡,分布在海拔1800~2200m区域的兽类物种最多,所占比例大于80%;而在海拔2600m以上区域,兽类种数降至最少,仅占50%左右。兽类丰富度的海拔梯度也体现于这些兽类在各植被类型中的分布上。中山针阔叶混交林中分布的兽类种数最多,而在中低山落叶阔叶林、亚高山针叶林及亚高山灌丛草甸中分布的兽类则较少。  相似文献   

2.
2007年3月~2008年2月对八仙山自然保护区兽类的区系特征和生态分布进行了研究.该保护区共有26种兽类,隶属6目13科,以古北界种类为主,为古北界逐渐向东洋界过渡区域.兽类生态分布分析表明,在落叶阔叶林中种类最多,针叶林中最少,种数随海拔升高具有先升后降的变化规律.  相似文献   

3.
神农架南坡植物群落多样性的海拔梯度格局   总被引:35,自引:3,他引:32  
神农架南坡在我国植被区划中具有十分重要的意义。在神农架南坡沿海拔梯度设置50个样方进行植物物种多样性调查,通过对样方的数量分类和DCA排序,结合物种丰富度、区系分化强度、区系成分和生活型构成等方面的分析,研究神农架南坡植物物种多样性的垂直格局。结果表明:(1)神农架南坡的植被垂直带谱为:海拔900—1000m以下为常绿阔叶林;1000-1700m为常绿落叶阔叶混交林;1600—2100m为落叶阔叶林;海拔2000—2400m为针阔叶混交林;海拔2300m以上为暗针叶林。(2)植被基带群落中,在物种数量、区系成分和重要值方面,常绿和落叶阔叶树种所占的比例都相差无几。(3)植物多样性的垂直格局基本符合“单峰”模式。峰值出现在海拔1400—1500m;但混交林类型的多样性和区系分化强度较高。(4)在植物区系中,温带成分处于主导地位;世界广布属的比例随海拔上升而增加;而中国特有属仅见于海拔2000m以下。亚热带成分和东亚区域性区系成分都随海拔上升而减少,峰值都位于山地常绿落叶阔叶混交林。(5)蕨类植物丰富度随海拔上升而减小;草本植物丰富度与海拔高度之间没有呈现显著的相关关系;木本植物丰富度总体沿海拔梯度减少,但峰椎处于常绿落叶阔叶林带。针阔混交林样方的平均木本物种数也超过落叶阔叶林带。  相似文献   

4.
孙治宇  刘少英  刘洋  赵杰  雷开明  朱宗福 《四川动物》2007,26(4):852-855,858
2002~2003年,对九寨沟国家级自然保护区的大中型兽类进行了6次大规模的调查。共调查大中型动物样线82条,实际调查记录到大中型兽类20种,样线上遇见各种大中型兽类痕迹或实体总计223次,均用GPS进行精确定位。统计表明,针叶林生境中物种最丰富;随海拔增高,总的趋势是古北界种类所占比例呈现增加趋势,但在海拔3600~4000 m之间,东洋界种类所占比例仍然较大(50%),动物区系呈现广泛的过渡性;随着海拔升高古北界种类样线的遇见率明显增加,3200 m以上这种趋势更为明显。在记录到的20种大中型兽类中,豹猫(Felis bengalen-si)分布的海拔跨度最大,为保护区的广布种;牛羚(Budorcas taxicolor)的遇见次数最多,是保护区的优势种。  相似文献   

5.
利用红外相机对浙江清凉峰国家级自然保护区龙塘山区域鸟兽物种多样性和丰富度进行调查。于2013年6月—2014年10月,在12个位点放置红外相机,每台相机在每个位点放置时间为7~17个月。共获得鸟兽有效照片1 840张,有效照片中兽类占69.35%,鸟类占30.65%。经鉴定,兽类有9种,鸟类有14种。兽类中拍摄率最高的是小麂Muntiacus reevesi、花面狸Paguma larvata和黑麂Muntiacus crinifrons,鸟类中拍摄率最高的是白鹇Lophura nycthemera、勺鸡Pucrasia macrolopha和白颈长尾雉Syrmaticus ellioti。红外相机在不同海拔和植物群落中的拍摄率各不相同,1 018~1 260 m海拔段高于811~995 m;在常绿落叶阔叶混交林中的拍摄率最高,针阔混交林最低。研究表明,红外相机陷阱技术对于调查和监测大中型兽类和部分鸟类具有一定优越性,所采集数据及图片对保护区科研监测具有重要意义。  相似文献   

6.
白水江自然保护区位于东经104°18′—105°25′,北纬32°35′—33°50′;总面积198488公顷(核心区90358公顷,实验区108310公顷)。全境为南秦岭山地,区内山峦重迭,山间河谷深陷。区内水系为长江水系。气候除河谷属亚热带湿润气候外,大部分为暖温带湿润气候,年平均温度15.9℃,最高37.5℃,最低—7.4℃。无霜期262天左右,年均降水量442毫米。植被呈明显垂直分布,可分下列四个植被带:一、低山常绿、落叶林带:海拔1600米以下,有大面积农耕区和居民点,植被以次生阔叶林为主。常见有麻栎、山楠、马桑、蔷薇等。二、中山阔叶林和混交林带:海拔1600—…  相似文献   

7.
后河自然保护区常绿落叶阔叶混交林群落学特征研究   总被引:10,自引:4,他引:6  
研究了后河国家级自然保护区常绿落叶阔叶混交林的区系特点、群落学特征。结果表明 :后河国家级自然保护区常绿落叶阔叶混交林群落物种丰富 ,有 110科 2 88属 5 34种 ,科的分布型以热带类型为主 ,属的分布型温带类型占优势 ,反映该群落区系以温带为主的亚热带区系特点 ;该混交林主要由以单叶、中型叶及非全缘叶为主的常绿、落叶阔叶高位芽植物组成 ,群落层次分明 ,从上至下 ,落叶阔叶树种所占比例逐渐减少 ,常绿阔叶树种比例逐渐增加 ;除两低海拔样地外 ,多样性变化幅度较小 ,各样地的物种多样性指数变化趋势基本一致。  相似文献   

8.
利用九寨沟自然保护区内8条动物监测样线在2003—2010年的生态监测数据,分析了植被、海拔、人为干扰对大中型野生动物分布的影响,结果显示:1)本监测共记录到保护区内大中型野生动物26种,其中兽类18种,鸟类8种,属于我国Ⅰ级、Ⅱ级保护动物的分别有5种和11种。2)针阔混交林和针叶林是大中型野生动物种类最丰富的两种植被类型(分别有26种和17种),阔叶林和灌丛次之(分别为10种和12种),草地最少(2种)。3)海拔2400 m以下的地方,大中型野生动物种类稀少,为10种,2400—2599 m海拔段物种数增加至20种,之后随海拔上升物种丰富度下降。4)人为干扰显著影响大中型野生动物的空间分布:历史上的人类活动将原生森林植被转化为次生的落叶阔叶林、灌丛和草地,使树正、亚纳和尖盘等地下坡位(相对海拔0—199 m)的大中型野生动物的物种丰富度降低(分别为4、2、2种)。包括旅游活动和交通在内的人为干扰,可能导致附近50m海拔范围内保护动物的缺失,并使下坡位的某些物种向高海拔处移动。生境破碎化则使野生动物的种类组成发生改变,使原有森林内部优势种,如羚牛(Budorcas taxicolor),逐渐被适应能力强的物种,如豹猫(Prionailurus bengalensis)、雉鸡(Phasianuscolchicus)和野猪(Sus scrofa)等所取代,并将长期影响野生动物种群的存活。当前九寨沟自然保护区大中型野生动物的分布是植被、海拔与人为干扰综合作用的结果。  相似文献   

9.
后河自然保护区常绿落叶阔叶混交林落学特征研究   总被引:2,自引:1,他引:1  
研究了后河国家级自然保护区常绿落叶混交林的区系特点,群落学特征,结果表明:后河国家级自然保护区常绿叶阔叶混交林群落物种丰富,有110科288属534种,科的分布型以热带类型为主,属的分布型温带类型占优势,反映该群落区系以温带为主的亚热带区系特点;该混交林主要由以单叶,中型叶及非全缘叶为主的常绿,落叶阔叶高位芽植物组成,群落层次分明,从上至下,落叶阔叶树种所占比例逐渐减少,常绿阔叶树种比例逐渐增加,除两低海拔样地外,多样性变化幅度较小,各样地的物种多样性指数变化趋势基本一致。  相似文献   

10.
查旦乡位于三江源腹地,生态地位极其重要,但兽类和鸟类本地资源尚未明确。本研究采用样线和样方结合法对该区域夏季兽类与鸟类多样性进行调查。共记录到到大中型兽类9种,隶属于5目5科8属,其中国家重点保护兽类4种。西藏野驴、藏原羚在区内为优势种,分别占兽类个体总数的45.5%和21.6%;鸟类11目26科44属52种,其中国家重点保护鸟类11种。鸟类中雀形目为优势种,占鸟类个体总数的81.0%。样区内兽类与鸟类物种数在不同海拔间存在显著差异(兽类:P<0.001;鸟类:P<0.001),兽类的垂直分布随海拔增加呈递减趋势,在海拔4800~4849 m段生物多样性水平最高;鸟类垂直分布格局符合向左偏移的“中峰模式”, 物种多样性指数随海拔增加而先增加后减小。本次研究掌握了查旦乡样区内夏季鸟兽组成情况,丰富了三江源保护区和唐古拉山脉的鸟兽资料,同时为相对较小尺度下物种空间分布格局的研究提供案例。  相似文献   

11.
A review is presented of issues relevant to the definition, measurement, and classification of stimuli, situations, and environments. Problems such as the lack of adequate definitions of concepts, error and bias in measurement procedures, confusion between measurement of a concept and measurement of its behavioral effects, and the lack of agreement among alternative measures are emphasized. It is suggested that concepts be defined in terms of objective characteristics while allowing for the study of the transactional relationship between organism and environment. The work of the ethologists in defining stimuli while studying their relationship to different organismic states and situational contexts is emphasized in this regard. Following Brunswik, it is also suggested that wherever possible there be a representative sampling of variables in natural settings. Note from the editors: From time to time, Human Ecology will publish a review article. Our first in this series is a review by a psychologist of basic definitional and conceptual problems in environmental studies.This paper was prepared while the author was a Visiting Research Fellow at the Educational Testing Service. The support of ETS and my colleagues in the Division of Psychological Studies is gratefully acknowledged. The review was also supported in part by a grant from the Rutgers University Research Council.  相似文献   

12.
13.
2-Dimethylaminomethylene-1-benzosuberone 1 was coupled with diazotized aniline derivatives to afford a series of the hitherto unreported 2-arylazo-1-benzosuberones 3ai. The tautomeric structure and the effect of substituents on the tautomeric form (s) of the products 3ai were discussed. Similar coupling of the enaminone 1 with diazonium salts of heterocyclic amines gave the respective fused azolotriazino-benzosuberones. Some of the newly synthesized compounds showed potent antimicrobial, anti-HCV, antioxidant, antitumor (as topoisomerase I inhibitors), and antimicrobial activities.  相似文献   

14.
15.
The Precautionary Principle is in sharp political focus today because (1) the nature of scientific uncertainty is changing and (2) there is increasing pressure to base governmental action on more “rational” schemes, such as cost-benefit analysis and quantitative risk assessment, the former being an embodiment of ‘rational choice theory’ promoted by the Chicago school of law and economics. The Precautionary Principle has been criticized as being both too vague and too arbitrary to form a basis for rational decision making. The assumption underlying this criticism is that any scheme not based on cost-benefit analysis and risk assessment is both irrational and without secure foundation in either science or economics. This paper contests that view and makes explicit the rational tenets of the Precautionary Principle within an analytical framework as rigorous as uncertainties permit, and one that mirrors democratic values embodied in regulatory, compensatory, and common law. Unlike other formulations that reject risk assessment, this paper argues that risk assessment can be used within the formalism of tradeoff analysis—a more appropriate alternative to traditional cost-benefit analysis and one that satisfies the need for well-grounded public policy decision making. This paper will argue that the precautionary approach is the most appropriate basis for policy, even when large uncertainties do not exist, especially where the fairness of the distributions of costs and benefits of hazardous activities and products are a concern. Furthermore, it will offer an approach to making decisions within an analytic framework, based on equity and justice, to replace the economic paradigm of utilitarian cost-benefit analysis.  相似文献   

16.
Indians, Markets, and Rainforests: Theory, Methods, and Analysis. Ricardo A. Godoy. New York: Columbia University Press, 2001. 274 pp.  相似文献   

17.
We compared the cardiovascular effects evoked in conscious dogs by 1) submaximal exercise; 2) infusion of dobutamine (40 micrograms X kg-1 X min-1); and 3) infusion of a combination of atropine (0.15 mg/kg), norepinephrine (0.19 micrograms X kg-1 X min-1), and epinephrine (0.05 micrograms X kg-1 X min-1). Myocardial O2 demand, as estimated by the double product (heart rate X systolic blood pressure), was similar during all three interventions. Cardiac output and heart rate increased significantly (P less than 0.05) during each of the three interventions. Arteriovenous O2 difference and total body O2 consumption, however, increased only during submaximal exercise. Although myocardial blood flow increased similarly during each of the three interventions, blood flow to skeletal muscle and the tongue increased only during exercise. Exercise and the combined infusion of atropine, norepinephrine, and epinephrine produced similar increases in blood flow to the diaphragm and similar decreases in blood flow to the stomach. These changes in blood flow were associated with appropriate changes in vascular resistance. Additionally, blood flow to the brain, kidney, adrenal glands, liver, and intestine did not change during any of the three interventions. Thus, in dogs, submaximal exercise, infusion of dobutamine, and infusion of a combination of atropine, norepinephrine, and epinephrine to evoke a given level of estimated myocardial O2 consumption produce similar increases in cardiac output, heart rate, and myocardial blood flow. In contrast, the changes in total body O2 consumption, arteriovenous O2 difference, regional blood flow, and regional vascular resistance that occur during each of these three interventions are different.  相似文献   

18.
19.
20.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号