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1.
葛洲坝及长江上海江面水鸟考察报告   总被引:6,自引:1,他引:5  
1 前 言葛洲坝及长江上游江面的水鸟 ,无前人考察。为了探讨葛洲坝及长江三峡枢纽工程对湿地水禽的影响 ,查明该江段水鸟的多样性、分布及种群数量 ,并为大坝建成后研究本区生态环境的改变提供对比资料和数据 ,我们于 1 980年 3月 1 9日至 4月 3日 ,1 981年 1 2月 1日至 1 6日和 1 983年 3月 2 0日至 2 8日 ,1 992年 1 1月和 1 996年1 1月至 1 2月对葛洲坝及其上游的水鸟进行了 53天的考察。现将所获数据及资料经分析整理报道如下。2 考察方法及地点1 980年 3月 1 9日至 4月 3日 ,1 981年1 2月 1日至 1 6日 ,1 982年 4月 (植被调查)和1 9…  相似文献   

2.
雅鲁藏布江流域底栖动物多样性及生态评价   总被引:4,自引:0,他引:4  
雅鲁藏布江起源于喜马拉雅山,是世界上海拔最高的河流之一,是流经我国西藏境内重要的国际河流,其河流生态系统具有特殊地貌及生态条件。研究该流域底栖动物多样性分布特征及其影响因子,是科学评价该区域河流生态系统健康状况,实现资源可持续开发利用的基础。2009年10月—2010年6月期间,以底栖动物作为指示物种,对雅江流域干支流及堰塞湖的14个采样断面进行河流生态评价。采用Alpha及Beta生物多样性指数分别指示局部采样河段及全区域的底栖动物多样性。对采样断面底栖动物组成分析发现:14个采样断面共采集到底栖动物110种,隶属57科102属。雅江干流底栖动物种类数最高为29,平均为19。支流年楚河种类数为17。支流拉萨河,尼洋河,帕龙藏布的最高种类数分别为25,33,36;平均种类数分别为21,21,22,生物多样性普遍高于干流。整个流域中底栖动物平均种类数相差不大,但种类组成和密度相差较大。调查区域的Beta多样性指数β高于低海拔地区的相似的山区河流,说明雅江流域内底栖动物群落差异性高于正常海拔地区。对14个采样断面的物种组成进行除趋势对应分析表明:影响雅江流域底栖动物多样性的主要因素为河型,河床阻力结构,堤岸结构,水流流速。保持稳定的阶梯-深潭结构和自然堤岸结构,以及适宜的流速有利于保护雅江河流生态。  相似文献   

3.
孙然好  程先  陈利顶 《生态学报》2018,38(12):4473-4481
城市群快速发展严重影响着区域水生态系统的完整性,大尺度流域的河流生境功能辨识和分析尚缺乏系统研究。以海河流域为例,根据河段蜿蜒度、河段比降、断流风险、盐度等4个指标,构建了河流生境功能的分类指标体系。通过多源空间数据和人工判读,划分了6254条河段,在此基础上将河流生境类型划分为15类。通过52个监测样点的鱼类调查数据,分析了不同河流生境的水生生物特征差异,揭示了鱼类多样性高的区域多位于河流比降大、断流风险低的区域,而河流蜿蜒度对于鱼类多样性影响较小。根据京津冀13个地级市的河流生境差异,提出京津冀城市群的生态安全构建需要充分考虑河流生境的空间异质性,并制定融合城市发展目标、水资源利用需求和河流生境功能的综合指标体系。  相似文献   

4.
长江江豚对八里江江段的利用及其栖息地现状的初步评价   总被引:11,自引:0,他引:11  
通过定点和流动观察的方法,作者使用行为指数和栖息地利用指数定量分析了长江江豚(Neophocaena phocaenoides asiaeorientalis))于1996—2000年间对八里江江段的利用和选择状况。结果表明:江豚在八里江江段的行为指数大小顺序为摄食>抚幼>玩耍>休息,摄食和抚幼是江豚在八里江江段的优势行为;江豚栖息于离岸距离100—300m的近岸带占81.8%,栖息于水深小于9m的水区占73.3%;江豚分布密度随水深增加而逐步递减(典型的指数分布);江豚活动水区的流速范围是0.3-1.2m/s,透明度范围是0.2—0.8m,江豚在八里江江段对水体流速和透明度没有明显的选择性;栖息地利用指数高的断面一般是饵料鱼类聚集、2—4股水流的交汇处。八里江江段的众多异质小生境为江豚提供了充足饵料和繁育抚幼的适宜场所;同时八里江江段为江豚提供了庇护、休息和玩耍的足够活动空间。八里江江段成为长江干流适宜江豚活动的最佳栖息地之一,也是常年江豚在此大规模集聚的理想江段之一[动物学报49(2):163—170,2003]。  相似文献   

5.
为研究长江中下游干流大型底栖动物的基本群落现状及其沿中下游的变化趋势, 于2019—2020年对长江中下游干流开展了3次野外调查。共记录大型底栖动物129属种, 总密度和总生物量(无灰干重)平均值分别为174 ind./m2和0.645 g/m2。自中游到下游干流, 大型底栖动物总种类数呈下降趋势; 水生昆虫密度下降, 其他类群密度上升; 直接收集者和刮食者密度呈下降趋势, 捕食者和撕食者密度上升。相关分析显示水深和平均流速是影响大型底栖动物分布的重要因素。总结了不同类群的分布模式: 寡毛类与摇蚊类均喜深水缓流, 两者适宜水深流速范围差异不大; 腹足类喜水浅缓流, 适宜水深与流速范围均较窄, 而双壳类则相反。其他水生昆虫类、多毛类和钩虾类适宜水深范围较宽, 流速范围相对较窄。研究结果可为今后开展长江中下游干流大型底栖动物环境水流需求研究和水库生态调度等保护与管理工作提供基础资料。  相似文献   

6.
快速城市化区域不同生境类型的蝴蝶多样性   总被引:2,自引:0,他引:2  
林芳淼  袁兴中  吴玉源  刘红 《生态学杂志》2012,31(10):2579-2584
2011年5—10月,在重庆两江新区选取人工次生林、人工草地、苗圃地、荒草地、农田、天然次生林6种不同生境类型,进行蝴蝶调查。共采集蝴蝶1547只,隶属6科27属37种。结果表明:菜粉蝶(Pieris rapae)、东方菜粉蝶(P.canidia)、酢浆灰蝶(Pseudozizeeria maha)和点玄灰蝶(Tongeia filicaudis)是研究区域的优势种;沿城市化梯度,不同采样断面蝴蝶多样性指数变化趋势明显,即城市化水平越高,多样性指数越低;同时生境类型和人为干扰对蝴蝶多样性影响明显;蝴蝶群落多样性特征可以作为生境质量和环境变化的指标。最后提出:在快速城市化区域中,应根据不同城市化水平、不同生境类型采取有差异的管理措施,保护和提高城市生物多样性。  相似文献   

7.
汉江水生植物多样性研究   总被引:11,自引:1,他引:10  
对汉江沿途 1 3个地区的所在江段进行了水生植物种类组成、分布、生物多样性调查。结果表明 ,在汉江共有水生植物 2 6科 3 6属 5 4种 ;物种α多样性在丹江口最高 ,H、D和R指数由上游汉中江段至下游汉口段表现出上升—下降—上升的三折线及四折线变化趋势 ;β多样性在水深梯度及距离梯度上表现为 β下 >β上 >β中 ,说明下游江段的生境异质性程度高 ;γ多样性是γ上 >γ中 >γ下 ,对各个江段而言以中游老河口江段γ多样性最大为 2 9种 ,丹江口和襄樊江段次之 ,汉口段最小。中游地区水生环境和生态因子更适合于水生植物的生长 ,而下游人类活动导致水环境趋于恶化限制了水生植物的生长和分布  相似文献   

8.
长江安庆江段刀鲚耳石微化学及洄游生态学意义   总被引:6,自引:0,他引:6  
李孟孟  姜涛  陈婷婷  刘洪波  杨健 《生态学报》2017,37(8):2788-2795
刀鲚(Coilia nasus)属辐鳍鱼纲、鲱形目、鳀科,是我国长江下游一种传统的名贵经济鱼类。长江安徽江段为刀鲚的主要分布区之一,但近年来由于人类活动干扰、栖息地衰退及过捕等原因,资源量急剧下降。近期发布的《国家重点保护野生动物名录》水生野生动物调整方案已拟将刀鲚列入国家二级重点野生动物保护名录。为客观了解长江安庆江段刀鲚的生境"履历"及探讨其洄游史,利用X射线电子探针微区分析技术对2008年7月捕获于长江安庆江段的10尾刀鲚(均为传统意义上的长颌鲚)进行了耳石微化学研究。结果表明:这些个体均具典型的溯河洄游习性。从耳石核心到边缘定量线分析结果表明,耳石的沉积过程中元素Sr/Ca比值波动显著,不仅有对应淡水生境的低值(3)阶段,还具有对应河口半咸水、海水生境的高值(3)阶段。这种现象亦得到了16色Sr元素面分布分析结果的印证。根据耳石淡水系数、Sr/Ca比值高低波动特征及Sr元素面分布图谱的差异性可以将这些刀鲚分为3种淡-海水生境转换生活史类型。这种现象明显地反映出长江安庆江段刀鲚的群体具有个体组成和洄游模式的多样性。  相似文献   

9.
基于耳石微化学的长江安徽和县江段刀鲚生境履历重建   总被引:3,自引:0,他引:3  
为了解长江刀鲚(Coilia nasus)的“生境履历”, 利用电子探针微区分析技术研究了2015年5月17日在长江安徽和县江段捕获的刀鲚短颌鲚与长颌鲚类型耳石Sr和Ca微化学特征。短颌鲚的耳石Sr/Ca值变化动态为2类, 一类比值稳定在2.00左右(1.65±0.87—2.03±0.96), 反映了其纯淡水的生境履历; 另一类比值波动显著, 不仅具有对应淡水生境的低值(2.39±1.18—2.63±0.85), 还具有对应半咸水生境的高值(3.22±1.17—3.29±1.14), 显现了其江海生活的生境履历。长颌鲚耳石的Sr/Ca值均波动显著, 同时具有对应淡水生境的低值(1.35±1.07—2.37±1.04)和半咸水、海水生境的高值(3.47±1.09—8.35±1.25), 表现了其均为溯河洄游的生境履历。Sr面分析结果也与上述Sr/Ca值的结果相印证。长江安徽和县江段刀鲚资源组成复杂, 群体可由纯淡水型和江海生活型的个体共同组成。  相似文献   

10.
梁道省  牟长城  高旭  鲁艺 《生态学报》2023,43(1):339-351
物种丰富度格局及其决定因素是生态学核心问题,但对其形成机制仍缺乏共识。为探究松嫩平原西部半干旱区沿湖岸至高地环境梯度(局地尺度)植物群落多样性分布格局及其决定因素,以沿该梯度依次分布的7种群落(狭叶香蒲沼泽、小香蒲沼泽、芦苇沼泽、草丛沼泽、拂子茅草甸、羊草草甸和榆树疏林)为对象,采用样带网格调查法及聚类分析法划分群落类型,测定物种丰富度、α多样性和β多样性及其环境因子(水位、土壤含水率、有机质等),揭示群落多样性空间分布规律及其形成机制。结果表明,沿湖岸至高地环境梯度:(1)物种丰富度(2.00—18.00)和α多样性(Simpson指数0.12—0.90;Shannon-Wiener指数0.23—2.57和Pielou指数0.34—0.88)总体上均呈类似N字型分布(在下部深水生境狭叶香蒲沼泽最低、中下部季节性积水生境草丛沼泽最高、中上部湿润生境拂子茅草甸较低、上部沙丘干旱生境榆树疏林又较高);(2)广义的β多样性(Jaccard指数0.56—0.96)可以分解成物种周转(丰富度没有变化的地点间的物种替代)和嵌套(物种贫乏地点是物种丰富地点子集时的物种差异)两个过程,其在该梯度上半段...  相似文献   

11.
Summary Concentration of N, P, K, Ca, Mg and S in summer groundnut crop was higher than in kharif while Zn, Fe, Mn and Cu contents were higher in summer crop. Kernel's N, P and Zn; Leaflet's Ca and Mn; Stem's K and Fe; Root's S and Cu and Petiole's Mg contents were highest. Shell's N, P, K, Mg, S, Zn and Cu; Kernel's Ca, Fe and Mn contents were the least. N, P, K, S, Zn and Cu concentrations decreased linearly as the crop grew. Ca, Mg, Fe and Mn concentrations did not display any distinct pattern. Ca concentration was positively correlated with pod yield in both the seasons.  相似文献   

12.
The cell has been represented as a charged liquid drop. Contrary to the DLVO-theory, the effect of the surface potential upon the value of the interfacial tension of the cell membrane has also been taken into consideration. The cell membrane has visco-elastic properties and its constituents may move against each other. Cell movement is caused by the appearance of a small number of the electrically charged constituents of the cell membrane on the leading edge of the cell. This produces a local decrease in the surface tension and the cell membrane expansion. At the moment of contact between two cells proton transfers occur between the strongly negatively charged microvilli of one cell and the body of the other, analogous to a condenser breakdown. This, through the effect on the surface tension, causes contact inhibition of movement. The distribution of the proton dissociable groups modifies the interaction between the cells (differentiation) and between the cell and the substratum (adhesion). Adsorption of the charged compounds at the surface of the cell membrane, decreasing the surface potential and increasing the surface tension, causes the phenomena of chemotaxis, phagocytosis and pinocytosis. Cell division, considered in the terms of the surface energy, requires an adequate supply of considerable quantities of energy inversely proportional to the surface potential value. In case of a reduction of the distance between the cells, their surface potential and the energetic barrier of the cell division processes increases, and causes contact inhibition of cell division. Due to their high charge, division of neoplastic cells is inhibited much later than division of normal cells, or is completely ininhibited due to geometric conditions. Fusion of the cell membrane in the intra-cellular and intercellular processes is a reverse process in relation to the cell division.  相似文献   

13.
Acute and chronic toxicity tests for malathion, diazinon, copper (Cu), mercury (Hg), lead (Pb), zinc (Zn), nickel (Ni), and iron (Fe) were conducted. Mortalities ofBarilius vagra andCyprinus carpio (common carp) were variable but LC50-96 hr were similar for pesticides. AdultB. vagra seem to be more sensitive to malathion than juvenile carp. Both juvenile carp and adultB. vagra were extremely sensitive to diazinon. Long-term exposure to pesticides modified morphology and behavior. The LC50-96 values for Cu, Hg, and Pb were 0.3, 0.16, and 0.44, respectively, for smaller fish and 1.0, 0.77, and 1.33, respectively, for larger fish. Replicate LC50 values for Zn, Ni, and Fe were somewhat variable, and for these metals, the size of the fish seemed to affect response because LC50 values increased as fish size increased. Cooper, Pb, Zn, and Fe residues following exposure to sublethal concentrations of these metals for 15 d were significantly greater in whole juvenile common carp than in controls.  相似文献   

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15.
The effect of age and gender on major, minor, and trace element contents in the intact rib bone of 80 relatively healthy 15–55-year-old women and men was investigated. Contents or upper limit of contents of 16 chemical elements in the rib bone were determined by inductively coupled plasma atomic emission spectrometry (ICP-AES). Mean values (M?±?SΕΜ) for the mass fraction of Ba, Ca, Cu, Fe, K, Li, Mg, Na, P, S, Sr, and Zn (milligram per kilogram of dry bone) were as follows: 2.54?±?0.16, 171,400?±?4,050, 1.35?±?0.22, 140?±?11, 1,874?±?71, 0.049?±?0.011, 2,139?±?38, 5,378?±?88, 75,140?±?1,660, 1,881?±?51, 291?±?20, and 92.8?±?1.5, respectively. The upper limits of contents of Al, B, Mn, and V were <7.20, <0.65, <0.36, and <0.03, respectively. Statistically significant tendency for the Ca, Mg, and P content to decrease with age was found in the human rib bone, regardless of gender. The mass fraction of Fe in the male rib bone increases with age. It was shown that higher Ca, Mg, Na, P, and Sr mass fractions as well as lower Fe content were typical of female ribs as compared to those in male ribs.  相似文献   

16.
The sieve-element plastids of 69 species of theCaryophyllales were investigated by transmission electron microscopy. All contained the specific subtype-P3 plastids characterized by a peripheral ring of protein filaments. The presence or absence of an additional central protein crystal and their shape being either polygonal or globular as well as the average sizes of the sieve-element plastids are useful features in the characterization of some families.—Barbeuia contains sieve-element plastids that confirm its placement within thePhytolaccaceae. Lyallia differs fromHectorella by including small starch grains in their sieve-element plastids, which otherwise by their globular crystals negate a closer connection to theCaryophyllaceae. The lack of a central protein crystal in its form-P3fs plastids placesMicrotea best within theChenopodiaceae. Sarcobatus, a so far uncontested member of theChenopodiaceae, contains form-P3cf plastids, i.e., including a central crystal not found elsewhere in this family.Telephium andCorrigiola, shifted back and forth betweenMolluginaceae andCaryophyllaceae, have form-P3cf(s) plastids with a polygonal crystal which favor their placement within theCaryophyllaceae.  相似文献   

17.
The translocation of the radionuclides of Co, Zn, Se, Rb, Y, Tc, and Re into red and green fruits, flesh, seeds, rind, calyxes, flower, leaves, and stems via the root of the tomato plant at two different growth stages was studied by a multitracer technique. The contents (%/g) of Co, Zn, Se, and Y in the roots were the highest among the organs, but only small amounts of them were translocated into the aerial parts after 5 d cultivation with a multitracer. In contrast, Rb, Tc, and Re showed rapid translocation into the stems and leaves from the root. In the plants cultivated for 95 d with a multitracer, Zn, Se, and Rb distributed in all of the organs, Co in the organs except for flowers, and Y, Tc, and Re in the limited organs. The translocation ratio of the elements for the edible part of the plants cultivated for 95 d decreased in the order of Rb>Zn>Co≈Se>Tc≈Y>Re. The transfer factor of the elements for tomato fruit was determined to be in the range of 10−5–10−2. The characteristic translocation behavior of the elements gives us fundamental information on the assessment of pollutant uptake by the tomato plant.  相似文献   

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19.
Piotrowska A  Bajguz A 《Phytochemistry》2011,72(17):2097-2112
Phytohormones, including auxins, abscisic acid, brassinosteroids, cytokinins, ethylene, gibberellins, and jasmonates, are involved in all aspects of plant growth, and developmental processes as well as environmental responses. However, our understanding of hormonal homeostasis is far from complete. Phytohormone conjugation is considered as a part of the mechanism to control cellular levels of these compounds. Active phytohormones are changed into multiple forms by acylation, esterification or glycosylation, for example. It seems that conjugated compounds could serve as pool of inactive phytohormones that can be converted to active forms by de-conjugation reactions. Some conjugates are thought to be temporary storage forms, from which free active hormones can be released after hydrolysis. It is also believed that conjugation serves functions, such as irreversible inactivation, transport, compartmentalization, and protection against degradation. The nature of abscisic acid, brassinosteroid, ethylene, gibberellin, and jasmonate conjugates is discussed.  相似文献   

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