社会关系网络分析在行为生态学中的跨学科应用

社会关系网络分析(social network analysis,SNA)是综合运用图论、数学模型,来研究个体与个体、个体与其所处社会网络、以及一个社会网络与另一社会网络之间关系的研究方法。SNA不仅仅是一套技术、而是一种关于关系网的方法论。该方法论认为每一个个体都不是独立的,而是通过信息、行为、空间分布、生态因素等连结共生。这让我们以全局视野理解一个动物群体,从两方关系、三方关系、个体与群体间关系、到动态网络模型等角度进行研究,为验证性行为与性选择理论、互惠与合作理论、信息流动与疾病传播理论、个体策略与种群选择理论、界定一个群、预测社会关系网络稳定性等行为生态学领域提供可靠的量化数据,极大地推动了行为生态学的发展。相对于国外的快速发展,SNA在国内动物学研究中的应用仍十分有限。为此,该文结合作者对川金丝猴的研究结果,介绍了SNA的理论背景、概念、测量方法和应用领域,旨在推广SNA在我国行为生态学研究中的跨学科应用。     

粪便DNA分析技术在动物生态学中的应用

粪便DNA分析是一项新发展起来的从粪便中获取动物DNA并用于相关研究的技术,该技术有助于分子生态学研究中所遇到的取样难题。通过对粪便DNA分析的研究方法、研究内容以及研究进展情况的介绍,提供了该技术不仅能用于分子生态学的许多研究领域,而且还能够提供诸如种群数量估计、领域边界划定等生态生态学信息,这是对分子生态学的重要补充。     

约束线方法在生态学研究中的应用

生态系统格局和过程往往受到多个因子的共同影响, 故此反映两个生态学变量相互关系的散点图常常会表现为有边界的散点云。基于数据均值或中值分析的传统统计方法不适用于散点云数据的分析。散点云所表征的不是两变量之间的相关关系, 而是限制作用关系。约束线(包络)方法为提取散点云边界、理解限制变量对响应变量的作用, 以及预测响应变量的潜在最大值提供了有效手段。该文对应用约束线方法研究生态学问题所取得的成果进行总结与归纳, 介绍了约束线概念的发展历程、提取方法, 从物种分布、种群行为及作物产量优化三个方面总结了约束线方法的优点及适用性, 概述了当前约束线方法应用研究面临的问题与挑战, 指出约束线方法应结合其他统计方法, 实现对生态过程的准确理解, 此外, 还应重视约束线方法的尺度依赖性。最后, 该文展望了约束线方法在研究生态系统服务关系和土地系统优化等方面的应用前景。     

人工神经网络模型及其在农业和生态学研究中的应用

对于一些复杂的农业生态系统,人们对其生态过程了解较少,且这些系统的不确定性和模糊性较大,用传统的方法难以模拟这些系统的行为,神经网络模型因为能较精确地模拟这些系统的行为,而引起生态学者们的广泛兴趣。该文着重介绍了误差逆传神经网络模型的结构、算法及其在农业和生态学中的应用研究。误差逆传神经网络模型一般采用三层神经网络模型结构,三层的神经网络模型能模拟任意复杂程度的连续函数,而且因为它的结构小而不容易产生与训练数据的过度吻合。误差逆传神经网络模型算法的主要特征是:利用当前的输入误差对权值进行调整。在生态学和农业研究中,误差逆传神经网络模型通常作为非线性函数模拟器用于预测作物产量、生物生产量、生物与环境之间的关系等。已有的研究表明:误差逆传神经网络模型的模拟精度要远远高于多元线性方程,类似于非线性方程,而在样本量足够的情况下,有一定的外推能力。但是误差逆传神经网络模型需要大量的样本量来保证所求取参数的可靠性,但这在实际研究中很难做到,因而限制了误差逆传神经网络模型的应用。近年来人们提出了强制训练停止、复合模型等多种技术来提高误差逆传神经网络模型的外推能力,也提出了Garson算法、敏感性分析以及随机化检验等技术对误差逆传神经网络模型的机理进行解释。误差逆传神经网络模型的真正优势在于模拟人们了解较少或不确定性和模糊性较大系统的行为,这些是传统模型所无法实现的,因而是对传统机理模型的重要补充。     

基于不同分析和取样方法研究褪黑激素对育成期母貂行为分配的影响

本文基于不同分析和取样方法研究褪黑激素对育成期母貂行为分配的影响.从貂场中随机选取当年出生的6只未埋植褪黑激素、6只埋植褪黑激素的美国短毛黑母貂.采用高清摄像头分别在埋植褪黑激素后的第30天(Ⅰ期)、第60天(Ⅱ期)、第75天(Ⅲ期)记录所有水貂的行为.埋植褪黑激素对水貂行为分配的影响,混合线性模型(mixed lin...     

空间和平衡理论在景观生态学中的发展和应用

传统生态学承认生态系统中平衡、稳定状态的存在 ,“自然平衡理论”是其集中体现。而近 30年来 ,非平衡理论的出现 ,使得人们对生态系统的认识发生了彻底的改变。非平衡理论认为 ,偶然事件 (如干扰等 )在生态过程中起着重要作用。随着认识的转变 ,对生态过程中的“空间”和空间异质性的理解也发生了变化 ,传统生态学总是试图回避空间动态和空间异质性问题 ,而着重强调时间格局的重要性。但在近 2 0年来 ,空间格局则得到了广泛重视。空间理论及空间格局的研究表明 ,空间异质性既可能增加生态系统和生态过程的稳定性 ,也可能降低其稳定性。分析两种变化趋势 ,指出了它们的相互关系 ,同时讨论了空间理论的发展及其在景观生态学中的应用 ,并阐述了生态平衡的含义。     

水稻氮行为模拟模型和数学优化程序结合在氮肥运筹中的应用

水稻氮行为模拟模型和数学优化程序结合在氮肥运筹中的应用郑志明严力蛟王兆骞（浙江农业大学农业生态研究所杭州３１００２９）徐照本楼余产（金华县农技推广中心金华３２１０００）＊浙江省自然科学基金和“作物生产模拟与系统分析（ＳＡＲＰ）”国际项目资助课题。收稿...     

Mantel方法在生态学中的应用

本文介绍了用于分析矩阵之间相关关系的Mantel检验和偏Mantel检验,并用生态学中的实例说明它们的具体应用.     

中性景观模型在景观生态学中的应用和发展

中性景观模型可以模拟产生大量具有相似统计特征而不包含特定生态过程或自然地理过程的格局,为研究真实景观提供一个参照系统,在大范围景观格局变化研究等方面提供便利.目前,中性景观模型成为景观生态学研究的一种重要方法和手段,已成功应用于检验现有景观指数并发展新的景观指数、景观格局对种群动态影响和干扰过程研究等多个领域.本文介绍了中性景观模型的产生、内涵和类型,阐述了中性景观模型在景观生态学中的应用.同时,展望了中型景观模型研究的发展方向:模型类型趋于多样化,结构趋于复杂化,着重模型模拟结果的验证,以及随着景观生态学理论和实践的发展、结合中性景观模型和景观生态学研究方法,深入地应用于格局和过程两者之间关系的研究.     

超声波遥测在水生动物生态学研究中的应用

超声波遥测应用于水生动物是基于海洋生物学家对自然环境中海洋动物的行为和生理研究的迫切需求而诞生的。目前已发展成为包括鱼类、甲壳类、豚类以及海龟等水生动物生态学研究的主要手段之一。本文回顾了超声波遥测应用于水生动物近50年来的发展历程,介绍了该技术的系统组成和使用方法,阐述了该技术的应用范围,分析了其应用于水生动物遥测所面临的问题,提出了相应建议和应用前景。     

Adaptive walks on behavioural landscapes and the evolution of optimal behaviour by natural selection

Summary One of the main challenges to the adaptationist programme in general and to the use of optimality models in behavioural and evolutionary ecology in particular is that natural selection need not optimise fitness. This challenge is addressed by considering the evolution of optimal patch choice by natural selection. The behavioural model is based on a state variable approach in which a strategy consists of a sequence denoting the patch to be visited as a function of the organism's state and time. The optimal strategy maximises expected terminal reproduction. The fitnesses of alternative strategies are computed by iteration of the associated equations for fitness; this characterises the adaptive behavioural landscape. There may be enormous numbers of strategies that have near optimal fitnesses. A population model is used to connect frequencies of behavioural types from one generation to the next. Theories on adaptive walks on fitness landscapes are considered in the context of behaviour. The main result is that within the context of optimality arguments at selective equilibrium, sub-optimal behaviours can persist. General implications for research in behavioural ecology, including tests of behavioural theories, are discussed.     

Foraging decisions and behavioural flexibility in trap‐building predators: a review

Foraging theory was first developed to predict the behaviour of widely‐foraging animals that actively search for prey. Although the behaviour of sit‐and‐wait predators often follows predictions derived from foraging theory, the similarity between these two distinct groups of predators is not always obvious. In this review, we compare foraging activities of trap‐building predators (mainly pit‐building antlions and web‐building spiders), a specific group of sit‐and‐wait predators that construct traps as a foraging device, with those of widely‐foraging predators. We refer to modifications of the trap characteristics as analogous to changes in foraging intensity. Our review illustrates that the responses of trap‐building and widely‐foraging predators to different internal and external factors, such as hunger level, conspecific density and predation threat are quite similar, calling for additional studies of foraging theory using trap‐building predators. In each chapter of this review, we summarize the response of trap‐building predators to a different factor, while contrasting it with the equivalent response characterizing widely‐foraging predators. We provide here evidence that the behaviour of trap‐building predators is not stereotypic or fixed as was once commonly accepted, rather it can vary greatly, depending on the individual's internal state and its interactions with external environmental factors.     

Temporal variation in reproductive costs and payoffs shapes the flowering strategy of a neotropical milkweed, <Emphasis Type="Italic">Asclepias curassavica</Emphasis>

A central goal of evolutionary ecology is to understand the factors that select for particular life history strategies, such as delaying reproduction. For example, environmental variation and reproductive costs to survival and growth often select for reproductive delays in semelparous and iteroparous species. In this study, we examine how variation in reproductive cost, which we define as a reduction to growth, survival, or future reproduction after a reproductive event, may select for reproductive delay in an iteroparous Neotropical milkweed with no obvious reproductive season. We analyzed demographic data collected every 3 months for 3 years from four populations of Asclepias curassavica in Monteverde, Costa Rica. We detected costs of flowering to survival and growth that varied in magnitude between our 12 transition periods without a seasonal pattern. The populations also exhibited temporal variation in reproductive payoffs measured as seedling establishment. We incorporated these reproductive costs into demographic projection models, which predicted a delayed flowering strategy only when we included temporal variation in costs and payoffs. Temporal variation in reproductive costs and payoffs is an important selective force in the evolution of delayed flowering in iteroparous species. Further, a lack of predictable seasonal pattern to reproductive costs and payoffs may contribute to the lack of seasonal reproductive patterns observed in our study species and other Neotropical species.     

不同耕作方法对水稻生长和土壤生态的影响

1998－1999年在华南双季稻田研究了不同耕作方法水稻生长和土壤生态的影响,结果表明,在抛秧条件下,免耗水稻分蘖数,有效穗数和实粒数减少,水稻产量比传统耕降低13．4％,经济效益减少10．9％,免耕土壤容重和硬度增大,癖孔隙度,非毛管孔隙度和有效P,K降低,放线菌和真菌数量减少,而土壤细菌数量增加,酶活性增强,轻耕和传统耕的土壤物理化学性质,微生物数量和酶活性相似,但轻耕水稻有效穗数和千粒重较高,水稻产量比传统耕增加2．1％,轻耕降低了耕作成本,经济效益比传统耕作提高11．0％。     

A note on the timing of tradeoffs in discrete life history models

We discuss the timing of tradeoffs in discrete life history models. With a simple mathematical example we show that different assumptions about the temporal order of costs and benefits resulting from a reproductive effort can lead to qualitatively different predictions. We examine two models taken from the literature, in which an implicit assumption is that benefits from reproductive efforts are received before the corresponding costs are paid. We show that the reverse assumptions would have led to very different results. Since there is no biological basis for a bias towards a particular set of assumptions, we conclude that a more flexible approach should be used when studying optimality problems that are based on discrete life histories.     

Beyond the phenotypic gambit: molecular behavioural ecology and the evolution of genetic architecture

Most studies of behaviour examine traits whose proximate causes include sensory input and neural decision-making, but conflict and collaboration in biological systems began long before brains or sensory systems evolved. Many behaviours result from non-neural mechanisms such as direct physical contact between recognition proteins or modifications of development that coincide with altered behaviour. These simple molecular mechanisms form the basis of important biological functions and can enact organismal interactions that are as subtle, strategic and interesting as any. The genetic changes that underlie divergent molecular behaviours are often targets of selection, indicating that their functional variation has important fitness consequences. These behaviours evolve by discrete units of quantifiable phenotypic effect (amino acid and regulatory mutations, often by successive mutations of the same gene), so the role of selection in shaping evolutionary change can be evaluated on the scale at which heritable phenotypic variation originates. We describe experimental strategies for finding genes that underlie biochemical and developmental alterations of behaviour, survey the existing literature highlighting cases where the simplicity of molecular behaviours has allowed insight to the evolutionary process and discuss the utility of a genetic knowledge of the sources and spectrum of phenotypic variation for a deeper understanding of how genetic and phenotypic architectures evolve.     

一个农户庭院经济的效益及其能流分析

一个农户庭院经济的效益及其能流分析方达福（湖北省阳新县农业环境保护站４３５２００）ＡｎａｌｙｓｉｓｏｆｔｈｅＥｃｏｎｏｍｉｃＢｅｎｅｆｉｔｓａｎｄＥｎｅｒｇｙＣｙｃｌｉｎｇｏｆｔｈｅＥｃｏｌｏｇｉｃａｌａｎｄＥｃｏｎｏｍｉｃＹａｒｄｉｎａＦａｒｍｅｒ...