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 0 毫秒
1.
刘阳  张正旺 《生态学报》2008,28(4):1354-1365
扩散是生物个体之间相互远离的单线性运动,是生物的基本特征之一,对种群的分布、动态及遗传结构等方面均有重要影响.扩散有出生扩散和繁殖扩散等主要形式.动物发生扩散的主要原因包括:避免近亲繁殖、减少竞争、改变繁殖地点等.近年来,扩散已经成为鸟类学研究的前沿领域.评述了鸟类扩散行为的性别差异、体质对于扩散的影响,阐述了扩散的基本过程及栖息地选择、长距离扩散等内容,同时介绍了环志标记、无线电遥测、分子生物学等研究鸟类扩散的主要方法.展望了鸟类扩散研究的发展趋势,认为新技术和新方法的应用将成为扩散生态学家关注的重要问题,未来研究将更加重视对鸟类扩散理论问题的探讨,而对鸟类扩散行为的研究成果也会更广泛地应用于濒危物种及其栖息地的保护工作中.  相似文献   

2.
    
Dispersal, defined as a linear spreading movement of individuals away from others of the population is a fundamental characteristic of organisms in nature. Dispersal is a central concept in ecological, behavioral and evolutionary studies, driven by different forces such as avoidance of inbreeding depression, density-dependent competition and the need to change breeding locations. By effective dispersal, organisms can enlarge their geographic range and adjust the dynamic, sex ratio and genetic compositions of a population. Birds are one of the groups that are studied intensively by human beings. Due to their diurnal habits, diverse life history strategies and complex movement, birds are also ideal models for the study of dispersal behaviors. Certain topics of avian dispersal including sex-biased, asymmetric dispersal caused by differences in body conditions, dispersal processes, habitat selection and long distance dispersal are discussed here. Bird-ringing or marking, radio-telemetry and genetic markers are useful tools widely applied in dispersal studies. There are three major challenges regarding theoretical study and methodology research of dispersal: (1) improvement in research methodology is needed, (2) more in-depth theoretical research is necessary, and (3) application of theoretical research into the conservation efforts for threatened birds and the management of their habitats should be carried out immediately. __________ Translated from Acta Ecologica Sinica, 2008, 28(4): 1354–1365 [译自: 生态学报]  相似文献   

3.
Dispersal, defined as a linear spreading move-ment of individuals away from others of the population is a fundamental characteristic of organisms in nature. Dispersal is a central concept in ecological, behavioral and evolutionary studies, driven by different forces such as avoidance of inbreeding depression, density-dependent competition and the need to change breeding locations. By effective dispersal, organisms can enlarge their geo-graphic range and adjust the dynamic, sex ratio and gen-etic compositions of a population. Birds are one of the groups that are studied intensively by human beings. Due to their diurnal habits, diverse life history strategies and complex movement, birds are also ideal models for the study of dispersal behaviors. Certain topics of avian dispersal including sex-biased, asymmetric dispersal caused by differences in body conditions, dispersal pro-cesses, habitat selection and long distance dispersal are discussed here. Bird-ringing or marking, radio-telemetry and genetic markers are useful tools widely applied in dispersal studies. There are three major challenges regard-ing theoretical study and methodology research of dis-persal: (1) improvement in research methodology is needed, (2) more in-depth theoretical research is neces-sary, and (3) application of theoretical research into the conservation efforts for threatened birds and the manage-ment of their habitats should be carried out immediately.  相似文献   

4.
5.
  总被引:1,自引:0,他引:1  
We studied effects of physical isolation on geographical variation in mtDNA RFLP polymorphisms and a suite of morphological characters within three species of neotropical forest birds; the crimson-backed tanager Ramphocelus dimidiatus, the blue-gray tanager Thraupis episcopus, and the streaked saltator Saltator albicollis. Variation among populations within continuous habitat on the Isthmus of Panama was compared with that among island populations isolated for about 10000 years. Putative barriers to dispersal were influential, but apparent isolation effects varied by species, geographical scale, and whether molecular or morphological traits were being assessed. We found no geographical structuring among the contiguous, mainland sampling sites. Migration rates among the islands appeared sufficient to maintain homogeneity in mtDNA haplotype frequencies. In contrast, variation in external morphology among islands was significant within two of three species. For all species, we found significant variation in genetic and morphological traits between the island (collectively) and mainland populations. Interspecific variation in the effects of isolation was likely related to differential vagility. These data generally corroborate other studies reporting relatively great geographical structuring within tropical birds over short distances. Behaviourally based traits - low vagility and high ‘sensitivity’ to geographical barriers - may underlie extensive diversification within neotropical forest birds, but more extensive ecological and phylogeographic information are needed on a diverse sample of species.  相似文献   

6.
7.
8.
    
Abstract. 1. The importance of dispersal capacity in structuring beta‐diversity gradients has been pointed out in a number of recent studies, making geographical distance (GD) an important predictor of the composition of assemblages apart from environment. In this study, we analyse the relative importance of climate, habitat complexity and GD in four spider families with different dispersal tendencies in the centre of the Iberian Peninsula. 2. Regional beta‐diversity was calculated for the four families and values were bootstrapped to test for significant difference between groups. Mantel tests assessed the explanatory capacity of four potential predictors – climatic similarity, similarity of vegetation complexity, GD and cost distance (CD) considering topography – on faunistic similarity. Simple regressions were used to compare decay rates, and bootstrapping tested for significant differences in coefficients. 3. Regional beta‐diversity values were higher in less vagile families. Climatic distance was strongly correlated with faunistic dissimilarity in the four families, whereas GD had no explanatory power. Except in one family, CD was correlated with faunistic dissimilarity but its independent association was negligible when controlling for climate. 4. Both the pattern of regional beta‐diversity among families and the pattern of variation in species composition explained by climate are consistent with the hypothesis that dispersion capacity influences the composition of the assemblages. However, climate distance was the main factor determining species sorting in space while GD had a weak effect. Differences in the degree of specialisation or nonlinear relationships between species composition and space may obscure the signal of GD at the scale of work.  相似文献   

9.
10.
    
Aim To evaluate the relative effectiveness of the lower and upper sections, respectively, of the Amazon River as a barrier to bird distribution, and to evaluate ecological and taxonomic factors affecting the efficacy of the river barrier. Location Amazon River of South America between its confluence with the Napo River in the west and its delta in the east. Methods Using published distribution maps for 448 species of passerine birds occurring along the Amazon River, we evaluated whether each was distributed along one bank only (river presumed to be a barrier) or both banks (no barrier) to test the predictions that the river was more effective as a dispersal barrier: (1) along the lower, wider portion of the river than the upper, narrower portion; (2) for species inhabiting forests than open country; (3) for species inhabiting forest understorey than forest canopy; (4) for species restricted to terra firme (never inundated upland forest) than those not restricted to terra firme and (5) for certain taxonomic groups. Results Our analyses demonstrated that the Amazon River was most effective as a dispersal barrier along its lower portion and for species restricted to forests and terra firme. However, the river was not significantly more of a barrier for species inhabiting forest understorey than forest canopy. The river was most significant as a barrier to dispersal for the antbirds (Thamnophilidae) and was less significant as a barrier to species belonging to several large families including woodcreepers (Dendrocolaptidae), ovenbirds (Furnariidae), flycatchers (Tyrannidae), cotingids (Cotingidae), tanagers (Thraupidae), seed‐eating finches (Emberizidae) and blackbirds (Icteridae). Main conclusions The robust widths of Amazonian rivers are widely considered to represent impediments to dispersal and gene flow for many taxa of birds and other animals, and may have represented agents of vicariance in the diversification of species. Our study reaffirms the effectiveness of the lower Amazon River as a current barrier to bird dispersal for forest birds and provides new insights into the effects of habitat and taxonomy on the efficacy of the river barrier. Although supportive of several predictions of the river hypothesis of biological diversification, our study is limited in addressing the historical impact of river barriers as agents of vicariance in the process of diversification.  相似文献   

11.
食肉质果鸟对种子的传播作用   总被引:8,自引:3,他引:8  
食肉质果鸟对种子的传播作用鲁长虎常家传(东北林业大学,哈尔滨150040)EffectoftheFleshy_fruitsEatingBirdsonSeedDispersal.LuChanghu,ChangJiachuan(NortheastFo...  相似文献   

12.
    
Long-distance dispersal (LDD) promotes the colonization of isolated and remote habitats, and thus it has been proposed as a mechanism for explaining the distributions of many species. Birds are key LDD vectors for many sessile organisms such as plants, yet LDD beyond local and regional scales has never been directly observed nor quantified. By sampling birds caught while in migratory flight by GPS-tracked wild falcons, we show that migratory birds transport seeds over hundreds of kilometres and mediate dispersal from mainland to oceanic islands. Up to 1.2% of birds that reached a small island of the Canary Archipelago (Alegranza) during their migration from Europe to Sub-Saharan Africa carried seeds in their guts. The billions of birds making seasonal migrations each year may then transport millions of seeds. None of the plant species transported by the birds occurs in Alegranza and most do not occur on nearby Canary Islands, providing a direct example of the importance of environmental filters in hampering successful colonization by immigrant species. The constant propagule pressure generated by these LDD events might, nevertheless, explain the colonization of some islands. Hence, migratory birds can mediate rapid range expansion or shifts of many plant taxa and determine their distribution.  相似文献   

13.
14.
15.
16.
17.
Abstract Reflection of ultraviolet (UV) light by the wings of the female Eurasian cabbage butterfly, Pieris rapae, shows a large geographic variation. The wings of the female of the European subspecies, P. rapae rapae, reflect little UV light, while butterflies of the Asian subspecies, P. rapae crucivora, may reflect it strongly or at only intermediate levels. The geographic region where P. rapae originated remains to be determined. Moreover, it is not clear if females with wings that reflect little UV light are ancestral to females with wings that reflect UV strongly or vice versa. In the present study, we aimed to determine the geographic origin and ancestral UV pattern of cabbage butterflies through mitochondrial DNA (mtDNA) sequence analysis and amplified fragment length polymorphism (AFLP) analysis. The results of these investigations suggest that P. rapae is of European origin and that it has expanded its distribution eastward to Asia. It follows that the ancestral subspecies is the type with UV‐absorbing wings. Lower nucleotide diversities and haplotype network patterns of mtDNA derived from East Asian populations suggest that population expansion from Europe to East Asia probably occurred fairly recently and at a rapid rate.  相似文献   

18.
本文对中国膜翅目昆虫2020年发表的新分类单元进行了梳理和总结。结合数据库检索和统计表格征集, 基于采自中国的膜翅目昆虫标本记录, 全世界膜翅目学者于2020年共发表涉及中国膜翅目分类单元的期刊论文104篇、出版1本图书专著, 分类单元新增及变动条目共469条: 4个新属(其中1个绝灭属), 1个新亚属, 321个新种(其中10个绝灭种), 8个新组合, 22个新异名, 1个中国新记录亚科, 18个中国新记录属, 93个中国新记录种, 1个替代名。绝灭类群有11条, 涉及3总科3科5属; 现生膜翅目有458条, 涵盖11总科29科170属, 其中6科40属不涉及新种。发表现生膜翅目新种的9总科23科130属: 广腰亚目(Symphyta)叶蜂总科(Tenthredinoidea) 23个新种; 细腰亚目(Apocrita)针尾部(Aculeata) 3个总科(蜜蜂总科(Apoidea) 29个新种、青蜂总科(Chrysidoidea) 2个新种、胡蜂总科(Vespoidea) 20个新种); 细腰亚目寄生部(Parasitica) 5个总科(小蜂总科(Chalcidoidea) 23个新种、瘿蜂总科(Cynipoidea) 12个新种、姬蜂总科(Ichneumonoidea) 206个新种、广腹细蜂总科(Platygastroidea) 4个新种、钩腹蜂总科(Trigonalyoidea) 2个新种)。2020年发表的所有中国膜翅目新种中, 姬蜂总科新种数量最多, 约占全年发表新种总数的2/3。云南、浙江、西藏、福建和辽宁等5个省级行政区为2020年中国膜翅目新种分布最多的省份, 超过全年发表新种总数的1/2。基于以上结果, 本文对膜翅目分类学现状和发展前景进行了讨论。  相似文献   

19.
Dispersal is a key mechanism to help populations propagate across space and thus is important in helping to understand spatial patterns. However, it is often difficult to quantify empirically as it requires intensive and detailed field study. Here we describe a method for estimating the effective dispersal distance of tropical plant populations. The method integrates a simple spatially explicit, individual-based dynamic model and spatial statistical analysis. The model is partly parameterized from spatial point pattern data as well as time series data from a 50 ha tropical forest plot in Barro Colorado Island (BCI) in Panama. Correlation between our estimated dispersal distances and those from inverse modeling based on field studies to date on BCI raises some questions about the match between our methods and those previously used. The method we propose can be generalized to any population for which spatial point pattern data are available. Additional field studies would be useful to further validate our method.  相似文献   

20.
Summary The probability of interspecific seedling competition from bird droppings is high because fruit-eating birds, on average, deposit more than two species in a single dropping. Moreover, birds vary both in the number of plant species they deposit in a given dropping and in the seed composition of those droppings. In a preliminary experiment, I examined effects of interspecific seedling competition from seeds found in bird droppings. Certain plant species were competitively superior in pairwise growth experiments using six common second-growth species. The survival of certain shrubs depended on which species it was disseminated with in bird droppings. Rapid germination time may promote competitive superiority in some cases. Birds affect plant fitness not only because of their behavior following dispersal, but also because they deposit seeds in different densities and combinations.  相似文献   

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