竹类植物种群生态学研究进展与展望

综述了竹类种群生理生态学、种群动态、繁殖特性、无性系种群特征等几个方面的研究进展,概括了群落水平上竹类种群对森林更新的影响。并从竹类种群克隆多样性与微进化、生长适应机理、开花机制,以及竹类种群与林窗更新等四个方面展望未来竹类种群生态学研究的重点和主要趋势。     

高寒草旬消费者种群稳定碳、氮同位素组成的海拔分异

通过测定青藏高原东部高寒区不同海拔主要植物和消费者种群（雀形目鸟类和小型哺乳类）的稳定碳、氮同位素比值,研究了高寒草甸消费者种群同位素组成特征及其影响因素。结果表明：植物平均稳定碳同位素随海拔升高表现出明显的增加趋势;消费者种群稳定碳、氮同位素随海拔的升高有明显的富集效应。雀形目鸟类种群稳定碳、氮同位素随海拔的升高均呈明显增加趋势;小型哺乳类稳定碳同位素随海拔上升不明显,而稳定氮同位素具有明显的增大趋势。消费者种群稳定碳、氮同位素沿海拔梯度的富集效应,一方面与植物稳定同位素在海拔梯度上的富集密切相关;另一方面与海拔和纬度变化所引起一系列环境因子的变化在一定程度上影响到动物的稳定同位素分布模式。另外,在高寒草甸地区,与雀形目鸟类相比,小型哺乳类在动物稳定同位素组成的代谢过程中更容易受到环境改变的影响。     

高寒草甸消费者种群稳定碳、氮同位素组成的海拔分异

通过测定青藏高原东部高寒区不同海拔主要植物和消费者种群（雀形目鸟类和小型哺乳类）的稳定碳、氮同位素比值,研究了高寒草甸消费者种群同位素组成特征及其影响因素。结果表明：植物平均稳定碳同位素随海拔升高表现出明显的增加趋势;消费者种群稳定碳、氮同位素随海拔的升高有明显的富集效应。雀形目鸟类种群稳定碳、氮同位素随海拔的升高均呈明显增加趋势;小型哺乳类稳定碳同位素随海拔上升不明显,而稳定氮同位素具有明显的增大趋势。消费者种群稳定碳、氮同位素沿海拔梯度的富集效应,一方面与植物稳定同位素在海拔梯度上的富集密切相关;另一方面与海拔和纬度变化所引起一系列环境因子的变化在一定程度上影响到动物的稳定同位素分布模式。另外,在高寒草甸地区,与雀形目鸟类相比,小型哺乳类在动物稳定同位素组成的代谢过程中更容易受到环境改变的影响。     

三宝鸟繁殖期领域性的初步研究

鸟类领域性是鸟类生态学研究中一个引人入胜而又争议颇多的课题(Nice,1941;Hinde,1956)由于对鸟类的领域性与生态因素、种群密度之间关系的深入讨论(Davies,1978;Brown,1969;Wesolowski,1981),使得这一课题已成为鸟类种群生态学研究的重要内容之一。了解各种鸟类的领域性表现和特点,无论在理论上和实践上都是有一定的意义的。 我国鸟类生态学研究工作主要集中在鸟类繁殖习性和区系分布等方面,个体行为生态学     

壶菌病与两栖动物的种群衰退

两栖类种群全球性衰退是21世纪最紧迫的环境问题之一。越来越多的证据表明壶菌(Batrachochytrium dendrobatidis)与澳大利亚、美洲北部、中部、南部及欧洲的两栖类种群衰退有关。由壶菌引起的壶菌病是变态后的无尾类所患的一种显性传染病,其令人质疑的快速传播及广泛爆发对世界范围内的两栖类种群构成重大威胁。本文对这种致病壶菌的病理学、生态学、生物地理学及其治疗方面的进展进行了综述。     

两栖类的繁殖迁徙研究概述

两栖类的繁殖迁徙是其繁殖活动的重要组成部分,个体能否成功完成繁殖迁徙将直接影响到繁殖成功率。两栖类的繁殖迁徙研究对于了解物种和种群对繁殖栖息地的需求、物种的繁殖活动规律,以及科学合理地进行繁殖湿地以及相应栖息地的规划、管理和保护具有重要意义。国际上对两栖类的繁殖迁徙已有大量的研究,内容涉及多个方面,而国内的研究还非常少。本文从两栖类的繁殖迁徙物候、迁徙模式、迁徙方向与定向、迁徙距离等方面总结了影响两栖类繁殖迁徙时间、繁殖迁徙方向的因素以及两栖类的定向和导航机制,分析了两栖类不同类群和性别在繁殖迁徙距离上的差异及其原因,介绍了两栖类繁殖迁徙常用的研究方法及其优缺点。开展两栖类繁殖迁徙的研究将对我国的两栖类保护具有重要意义。     

内蒙古达茂旗腾格淖尔地区大沙鼠种群繁殖习性的调查

鼠类繁殖生态学的研究是其种群生态学研究的一个重要方面 ,它不但为研究鼠类种群数量变动规律对种群数量进行预测预报提供重要的生态学基础资料 ,也为控制鼠害措施的制定提供依据 ,同时也具有重要的流行病学意义。大沙鼠 (Ｒｈｏｍｂｍｙｓｏｐｉｍｕｓ)广泛分布于中亚细亚、哈萨克斯坦、伊朗、阿富汗和蒙古国等地 ,在我国主要分布于内蒙古西部、甘肃北部和新疆 ,是荒漠—半荒漠地区的重要害鼠。我国对其生态学方面多注重于种群分布格局的研究[1～ 5] ,在繁殖方面的研究甚少[6] 。 1 979～1 980年和 1 995～ 1 996年对内蒙古包头市达尔罕茂…     

鸟类栖息地片段化研究的理论基础

栖息地片段化是导致许多森林鸟类种群下降的主要原因之一,而对栖息地片段化的形成及其影响的研究已是成为鸟类生态学的研究热点之一。介绍了鸟类栖息地片段化研究的理论基础,即岛屿生物地理学理论、景观生态学理论以及集合种群理论等,并阐述了鸟类栖息地片段化研究范式转变的原因。     

中国鸟类生态学的发展现现状

中国鸟类生态学的发展可分三个阶段;20世纪30年代至50年代末的萌芽期;60年代初至70年代末的成长期;80年代以来的蓬勃发展期。1990年以来,繁殖是我国鸟类生态学的最主要研究内容,论文数量比例占23.53%;行为,栖息地,群落和迁徙等方面的研究有明显增长;鸟类食性研究的关注程度下降,本文对繁殖,行为,栖息地,种群和群落内容研究现状进行详细分析。并提出了今后中国鸟类生态学研究与发展予以关注的问题。     

庞泉沟自然保护区褐马鸡种群生态初步研究

有关褐马鸡(Crossoptilon mantchuricum)的生态学研究已有记述,但涉及种群生态学内容的还不多。探究褐马鸡的种群特征,查明其种群密度繁殖能力、年龄组成、性别比例等鸟类种群生态学方面的内容,在学术和科学保护     

Density dependence in the terrestrial life history stage of two anurans

Populations of species with complex life cycles have the potential to be regulated at multiple life history stages. However, research tends to focus on single stage density-dependence, which can lead to inaccurate conclusions about population regulation and subsequently hinder conservation efforts. In amphibians, many studies have demonstrated strong effects of larval density and have often assumed that populations are regulated at this life history stage. However, studies examining density regulation in the terrestrial stages are rare, and the functional relationships between terrestrial density and vital rates in amphibians are unknown. We determined the effects of population density on survival, growth and reproductive development in the terrestrial stage of two amphibians by raising juvenile wood frogs (Rana sylvatica) and American toads (Bufo americanus) at six densities in terrestrial enclosures. Density had strong negative effects on survival, growth and reproductive development in both species. We fitted a priori recruitment functions to describe the relationship between initial density and the density of survivors after one year, and determined the functional relationship between initial density and mass after one year. Animals raised at the lowest densities experienced growth and survival rates that were over twice as great as those raised at the highest density. All female wood frogs in the lowest density treatment showed signs of reproductive development, compared to only 6% in the highest density treatment. Female American toads reached minimum reproductive size only at low densities, and male wood frogs and American toads reached maturity only in the three lowest density treatments. Our results demonstrate that in the complex life cycle of amphibians, density in the terrestrial stage can reduce growth, survival and reproductive development and may play an important role in amphibian population regulation. We discuss the implications of these results for population regulation in complex life cycles and for amphibian conservation.     

Amphibians as models for studying environmental change

The use of amphibians as models in ecological research has a rich history. From an early foundation in studies of amphibian natural history sprang generations of scientists who used amphibians as models to address fundamental questions in population and community ecology. More recently, in the wake of an environment that human disturbances rapidly altered, ecologists have adopted amphibians as models for studying applied ecological issues such as habitat loss, pollution, disease, and global climate change. Some of the characteristics of amphibians that make them useful models for studying these environmental problems are highlighted, including their trophic importance, environmental sensitivity, research tractability, and impending extinction. The article provides specific examples from the recent literature to illustrate how studies on amphibians have been instrumental in guiding scientific thought on a broad scale. Included are examples of how amphibian research has transformed scientific disciplines, generated new theories about global health, called into question widely accepted scientific paradigms, and raised awareness in the general public that our daily actions may have widespread repercussions. In addition, studies on amphibian declines have provided insight into the complexity in which multiple independent factors may interact with one another to produce catastrophic and sometimes unpredictable effects. Because of the complexity of these problems, amphibian ecologists have been among the strongest advocates for interdisciplinary research. Future studies of amphibians will be important not only for their conservation but also for the conservation of other species, critical habitats, and entire ecosystems.     

Density, climate and varying return points: an analysis of long-term population fluctuations in the threatened European tree frog

Experimental research has identified many putative agents of amphibian decline, yet the population-level consequences of these agents remain unknown, owing to lack of information on compensatory density dependence in natural populations. Here, we investigate the relative importance of intrinsic (density-dependent) and extrinsic (climatic) factors impacting the dynamics of a tree frog (Hyla arborea) population over 22 years. A combination of log-linear density dependence and rainfall (with a 2-year time lag corresponding to development time) explain 75% of the variance in the rate of increase. Such fluctuations around a variable return point might be responsible for the seemingly erratic demography and disequilibrium dynamics of many amphibian populations.     

Amphibian declines: future directions

Abstract. The amphibian decline problem is complex, and there is no easy solution. I highlight four major areas of future research that should increase our ability to detect declines, elucidate their underlying mechanisms, and advance our capacity to manage and conserve amphibian populations. First, a statistically sensitive monitoring approach is necessary to determine the distribution and abundance of amphibian populations, to assess whether they are declining, and to quantify the extent of declines. Most amphibian populations characteristically fluctuate, detection probabilities may be low for many species and populations tend to decline in numbers between years more often than they increase. These traits make establishing monitoring programmes difficult and distinguishing declines from natural fluctuations challenging. It is thus necessary to determine the best monitoring techniques based on their statistical power and to use appropriate statistical methods for detecting population trends. Secondly, although amphibian population studies occur most commonly at single or few breeding sites, research should occur often at the landscape level, and conservation efforts should focus on suitable habitat (whether or not it is occupied) and dispersal capabilities of species. Metapopulation dynamics are probably important for many species, but we must be cautious how we define metapopulations. That is, the term ‘metapopulation’ is currently used to define a wide range of demographic situations in amphibian populations, each with different management implications. Thirdly, recent advances in molecular genetic techniques make it possible to infer demographic events such as effects of recent fragmentation, bottlenecks or hybridization. Molecular techniques can be used in conjunction with census surveys to bolster knowledge about demographic processes such as declines. Alternatively, in the absence of long‐term census data, molecular data can be used to infer population trends. New genomic approaches may make estimating adaptive genetic variation more feasible. Fourthly, multi‐factorial studies are needed to disentangle the complexity of the several putative causes that probably interact to cause amphibian declines. Recent studies demonstrate the value of a multi‐factorial approach, and more work is needed to elucidate the synergistic effects of multiple environmental factors affecting amphibian populations simultaneously worldwide.     

小型哺乳动物亲缘关系对其种群动态的作用

主要综述小型哺乳动物亲缘关系对其种群动态的作用及其研究进展。与非亲缘个体比较,亲缘个体间的相互作用趋于亲密、巢区共享程度高,亲缘关系水平对扩散有明显的作用。亲缘关系水平的差异可改变种群增长速率及种群统计学特征,对提高雌体存活率、后代断乳成功率、后代存活率及性比具有显的作用。亲缘关系的分子生态学研究主要集中于亲权鉴定和种群遗传结构的分析。     

Demographic sensitivity and persistence of the threatened white- and orange-bellied frogs of Western Australia

Anurans have been the subject of numerous experimental and monitoring studies, yet their autecology under natural conditions remains poorly understood. Previous work has focussed on the pre-metamorphic life stages, with data suitable for estimating demographic parameters for all life stages collected in few species. This deficiency has almost certainly confounded current views of amphibian autecology and understanding of which mechanisms of decline represent the greatest threats to the persistence of amphibian species. We used a stage-structured metapopulation model, parameterised with comprehensive field data, to explore the sensitivity of two species of myobatrachid frogs from the southwest of Australia, Geocrinia alba and G. vitellina, to changes in demographic parameters at all life stages. The simulation modelling indicated that the population dynamics of both species were consistently most sensitive to changes in juvenile survival, then to fecundity, and third to both adult survival and standard deviation of survival to about equal extent. In practical terms, this indicates that management interventions which attempt to mitigate reductions in juvenile survival are likely to be most successful in arresting anuran metapopulation declines.     

Carryover effects from environmental change in early life: An overlooked driver of the amphibian extinction crisis?

Ecological carryover effects, or delayed effects of the environment on an organism's phenotype, are central predictors of individual fitness and a key issue in conservation biology. Climate change imposes increasingly variable environmental conditions that may be challenging to early life-history stages in animals with complex life histories, leading to detrimental physiological and fitness effects in later life. Yet, the latent nature of carryover effects, combined with the long temporal scales over which they can manifest, means that this phenomenon remains understudied and is often overlooked in short-term studies limited to single life-history stages. Herein, we review evidence for the physiological carryover effects induced by elevated ultraviolet radiation (UVR; 280–400 nm) as a potential contributor to recent amphibian population declines. UVR exposure causes a suite of molecular, cellular and physiological consequences known to underpin carryover effects in other taxa, but there is a lack of research linking embryonic and larval UVR exposures to fitness consequences post-metamorphosis in amphibians. We propose that the key impacts of UVR on disease-related amphibian declines are facilitated through carryover effects that bridge embryonic and larval UVR exposure with potential increased disease susceptibility post-metamorphosis. We conclude by identifying a practical direction for the study of ecological carryover effects in amphibians that could guide future ecological research in the broader field of conservation physiology. Only by addressing carryover effects can many of the mechanistic links between environmental change and population declines be elucidated.     

Early-life density-dependence effects on growth and survival in subantarctic fur seals

Understanding the regulation of natural populations has been a long-standing research program in ecology. Current knowledge on marine mammals and seabirds is biased toward the adult component of populations and lacking are studies investigating the juvenile component. Our goal was to estimate demographic parameters on the pre-weaning stage of a subantarctic fur seal (Arctocephalus tropicalis) population on Amsterdam Island, suspected to be regulated by density-dependence. The influence of abundance on growth parameters (length and weight) and survival was assessed over a study period spanning 16 years. We evidenced a negative trend in population growth rate when density increased. Density-dependence models were favored for pup body size and mass growth. Abundance had a clear influence on body length at high population-density, pups grew slower and were smaller at weaning than pups born in years with low population density. Abundance partly explained pup body mass variation and a weak effect was detected on pre-weaning survival. The causal mechanisms may be increased competition for food resources between breeding females, leading to a reduction of maternal input to their pups. Our results suggested that pup favored survival over growth and the development of their diving abilities in order to withstand the extreme fasting periods that are characteristic of this fur seal population. This analysis provides significant insight of density-dependent processes on early-life demographic parameters of a long lived and top-predator species, and more specifically on the pre-weaning stage with important consequences for our understanding of individual long-term fitness and population dynamics.     

There Is No Evidence for a Temporal Link between Pathogen Arrival and Frog Extinctions in North-Eastern Australia

Pathogen spread can cause population declines and even species extinctions. Nonetheless, in the absence of tailored monitoring schemes, documenting pathogen spread can be difficult. In the case of worldwide amphibian declines the best present understanding is that the chytrid fungus Batrachochytrium dendrobatidis (Bd) has recently spread, causing amphibian declines and extinction in the process. However, good evidence demonstrating pathogen arrival followed by amphibian decline is rare, and analysis of putative evidence is often inadequate. Here we attempt to examine the relationship between Bd arrival and amphibian decline across north-eastern Australia, using sites where a wave-like pattern of amphibian decline was first noticed and at which intensive research has since been conducted. We develop an analytical framework that allows rigorous estimation of pathogen arrival date, which can then be used to test for a correlation between the time of pathogen arrival and amphibian decline across sites. Our results show that, with the current dataset, the earliest possible arrival date of Bd in north-eastern Australia is completely unresolved; Bd could have arrived immediately before sampling commenced or may have arrived thousands of years earlier, the present data simply cannot say. The currently available data are thus insufficient to assess the link between timing of pathogen arrival and population decline in this part of the world. This data insufficiency is surprising given that there have been decades of research on chytridiomycosis in Australia and that there is a general belief that the link between Bd arrival and population decline is well resolved in this region. The lack of data on Bd arrival currently acts as a major impediment to determining the role of environmental factors in driving the global amphibian declines, and should be a major focus of future research.