大尺度陆地生态系统动态变化与空间变异的过程模型及模拟系统

当代生态系统科学研究更加关注区域生态环境及生态系统状态变化的监测、评估、预测、预警及生态环境可持续管理。在深入理解陆地生态系统的要素、过程、功能、格局及其相互作用机理基础上,发展生态系统定量化描述方法和数值模拟技术,集成构建大陆尺度的“多过程耦合-多技术集成-多目标应用”的陆地生态系统数值模拟器已成为生态系统与全球变化及其资源、环境和灾害效应科学研究的重要科技任务。本研究围绕宏观生态系统模拟分析方法问题,在回顾陆地生态系统模型研究现状和发展趋势的基础上,深入讨论开发大尺度陆地生态系统动态变化和空间变异及其资源环境效应模拟系统的理念,以及模拟系统的功能定位、结构设计等基本问题,为构造中国陆地生态系统数值模拟器提供参考。     

湖泊的水生态模型

由于城市化进程的不断加快,大量的污染物排放到湖泊中,打破了湖泊的生态平衡.湖泊的水生态模型不仅能够研究湖泊的富营养化现象,而且还可以模拟工业毒物等污染物对湖泊生态系统的影响,是湖泊管理的有力工具.本文从分析湖泊的污染现状以及污染趋势出发,介绍了湖泊水生态模型的研究现状,并根据模型的模拟对象和空间模拟能力对湖泊水生态模型进行了分类.在此基础上介绍了AQUATOX、PAMOLARE、CAEDYM、WASP、OOMAS等比较成熟的模拟湖泊生态系统的模型软件,阐述了它们的产生、发展、主要特点以及应用,总结了当今湖泊水生态模型在模拟过程中遇到的问题,并对水生态模型的发展趋势进行了展望.本文为湖泊水生态模型的选择提供了建议.     

水生模型生态系统研究

本文阐述了水生模型生态系统的基本概念、类型、发展概况及存在问题。着重介绍各种不同类型水生模型生态系统的基本结构、研究方法及其在评价整体生态效应中的应用意义并就目前水生模型生态系统研究中存在的主要问题及今后努力方向作了简要的评述。     

介绍一种建立池塘能流模型的方法

系统生态学是对生物群落的生存、成长和死亡进行宏观研究。其系统方法论有多种处理问题的方法,特别是框图模型的应用尤其广泛,如在海洋、经济、城市、水体和陆地生态系统均有应用,但仅局限于画画框图讨论而已,并没有指出其应用的实际意义。还有一种系统动力学框图,属臆造模型。     

区域生态系统风险管理的EVR模型及其应用研究

系统探讨了生态风险的成因、内涵;结合当前国际上流行的VaR风险管理模型,在生态风险理论有关研究的基础上．建立了一类新颖而实用的区域生态系统风险管理模型-EVR。并对模型的特点、性质、建模思想、参数选取的进一步完善和改进工作进行了详细的阐述。最后,以干旱风险为例,对EVR模型进行了应用研究。     

陆地碳循环研究中的模型方法

陆地碳循环是全球变化研究中的重要内容,碳循环模型已成为研究陆地碳循环的必要方法．其中气候变化、大气ＣＯ２浓度上升以及人类活动引起的土地利用和土地覆盖变化导致陆地生态系统在结构、功能、组成和分布等方面的变化及其反馈关系对陆地碳循环的影响是模型模拟的关键问题．生物地理模型和生物地球化学模型是碳循环模型的两大类型,建模方法、模型性质、特点和应用范围各异．碳循环模型的发展方向是综合两类模型的特点,建立全球动态碳循环模型．     

渤海生态通道模型初探

生态通道模式（Ｅｃｏｐａｔｈ Ｍｏｄｅｌ）是一种较为方便地研究生态系统结构,特别是水域生态系统结构的工具,它根据能量平衡原理,用线性齐次方程组描述生态系统中的生物组成和能量在各生物组成之间的流动过程,定量某些生态参数,如生物量、生产量／生物量、消耗量／生物量、营养级和生态营养效率（ＥＥ,Ｅｃｏｔｒｏｐｈｉｃ Ｅｆｆｉｃｉｅｎｃｙ）等,它能够给出能量在生态通道上的流动量,便于对生态２系统的特征和变化     

湖泊生态系统动力学模型研究进展

从系统分析在湖泊生态系统动力学研究中的作用出发,对湖泊生态系统的动力学建模过程、方法和软件等进行了总结.在此基础上,综述了国内外湖泊生态系统动力学模型的发展.从1960年代至今,湖泊生态系统动力学模型从简单的零维模型发展到复杂的水质水动力学生态综合模型和生态结构动力学模型,如LakeWeb模型.中国的湖泊生态系统动力学模型研究始于20世纪80年代,主要集中在滇池、太湖、东湖和巢湖等富营养化严重的湖泊以及其他水体.目前,已经开发一些软件用于湖泊生态系统动力学模拟,主要有CEQUALICM、WASP、AQUATOX、PAMOLARE、CAEDYM等,以及用来模拟湖泊能流的软件ECOPATH.湖泊生态系统动力学模型还在监测、数据共享和模型结构、参数选取和不确定性分析等方面存在不足,需在今后的研究中加以改进.     

一个三物种生态系统模型

本文利用属性集合来定义物种,对于同一物种中的不同个体,各种属性所表现出的强度不同,导致了个体之间的差异性．对一个物种而言,它具有的某方面功能是由物种的不同属性体现于这方面的能力所共同决定的．本文对具有环状捕食结构的三物种构成的生态系统,以各物种的每个属性对和捕食逃逸能力的贡献方式为基础,将属性分为四类．讨论了四类属性随时间的演化规律．从所得的结果发现,随着时间的延伸,三物种可以稳定的共存;另外,对物种捕食和逃逸有利的属性在平均意义下是进化的,而对捕食和逃逸无作用的属性却无法被淘汰．     

Problems of terminology in the teaching of plant water relations

The considerable variation and confusion in terminology used in the teaching of plant water relations is discussed. The concept of water potential is described briefly and compared with the older concepts of diffusion pressure deficit and suction pressure. The advantages of using water potential terminology are considered. Reference is made to some well-known student texts to illustrate the conflicting meanings of osmotic terms and symbols, and attention is drawn to the problems which arise when authors mix old and new terms. It is recommended that the new terminology should be incorporated into school examination syllabuses and textbooks as soon as possible.     

A neutral terminology to define 'invasive' species

The use of simple terms to articulate ecological concepts can confuse ideological debates and undermine management efforts. This problem is particularly acute in studies of nonindigenous species, which alternatively have been called ‘exotic’, ‘introduced’, ‘invasive’ and ‘naturalised’, among others. Attempts to redefine commonly used terminology have proven difficult because authors are often partial to particular definitions. In an attempt to form a consensus on invasion terminology, we synthesize an invasional framework based on current models that break the invasion process into a series of consecutive, obligatory stages. Unlike previous efforts, we propose a neutral terminology based on this framework. This ‘stage‐based’ terminology can be used to supplement terms with ambiguous meanings (e.g. invasive, introduced, naturalized, weedy, etc.), and thereby improve clarity of future studies. This approach is based on the concept of ‘propagule pressure’ and has the additional benefit of identifying factors affecting the success of species at each stage. Under this framework, invasions can be more objectively understood as biogeographical, rather than taxonomic, phenomena; and author preferences in the use of existing terminology can be addressed. An example of this recommended protocol might be: ‘We examined distribution data to contrast the characteristics of invasive species (stages IVa and V) and noninvasive species (stages III and IVb)’.     

Ditch the niche – is the niche a useful concept in ecology or species distribution modelling?

In this first of three papers we examine the use of niche concepts in ecology and especially in species distribution modelling (SDM). This paper deliberately focuses on the lack of clarity found in the term ‘niche’. Because its meanings are so diverse, the term niche tends to create confusion and requires constant qualification. The literature houses many idiosyncratic ideas of what the niche is, but few examples where niche is more explanatory than the terminologies of population and community ecology or the statistical methods used to implement SDM analyses. In many cases the original (and inspirational) concepts are not directly applicable to our modern applications (e.g. set theory). There are some conceptual limitations found in individual definitions of niche (e.g. the fundamental niche concept), so it is perhaps understandable why more neutral terminology is becoming popular in SDM. An examination of the literature reveals a wide range of uncritical use of niche terminology. Our findings in this paper do not necessarily support the position of niche as a universally useful concept.     

Human Associations and Their Characteristics

Human associations are among the chief, yet perhaps least explored, problems in Soviet social psychology. Moreover, terminology regarding this subject, which is still very fluid, complicates the problem even further. Often the same concept conceals different meanings or, conversely, the same meaning is covered by different concepts.     

BILDUNG UND GEBRAUCH VON BEGRIFFEN IN DER PALÄOÖKOLOGIE

During the past 20 years, palaeoecology has established itself as a concept in palaeontology and geology. As in other interdisciplinary sciences, the interchange of methods and terminology between the branches involved has led to changes in the meaning of the terms, and changes or confusion in the corresponding scientific concepts. This calls for stricter adherence to the original definition of the terms in many cases and for their redefinition in others. Starting with a critical review of the scientific and methodological range of palaeoecology, this paper presents a reconsideration of its basic concepts, with proposals concerning the conservation or redefinition of terms and with special regard to terms coined in German literature. It is desirable that similar revisions be undertaken in other language areas in order to attain a stricter, internationalized terminology, preferably substantiated in a dictionary.     

Commentary: do we have a consistent terminology for species diversity? We are on the way

A consistent terminology for species diversity is subject of an ongoing debate. Recently Tuomisto (Oecologia 164:853–860, 2010) stated that a consistent terminology for diversity already exists. The paper comments on recent papers by ourselves (Jurasinski et al. Oecologia 159:15–26, 2009) and by Moreno and Rodriguez (Oecologia 163:279–282, 2010). Both started from Whittaker’s diversity concept to discuss the ambiguities of the terminology and propose a new, more consistent terminology that is based on the different approaches to diversity analysis. In contrast, Tuomisto adheres to a strict school of thinking and derives a diversity framework in the sense of Whittaker (alpha, beta, gamma) from the conceptual definition of diversity itself. A third group of papers discusses appropriate methods for the analysis of the variation in species composition. Here, we support the idea that alpha, beta and gamma diversity should be used in a strict sense that is based only on the conceptual definition of diversity. We accordingly extend and modify our terminological concept for species diversity. All approaches to the analysis and quantification of species composition and diversity can be assigned to three abstraction levels (species composition, variation in species composition,and variation in variation in species composition) and two scale levels (sample scale, aggregation scale). All methods that investigate the variation in species composition across scale levels evaluate beta relation with beta diversity being just one form of beta relation, which is calculated by dividing gamma diversity of order q by the appropriate alpha diversity of the same order. In contrast, differentiation refers to a pairwise calculation of resemblance in species composition. It is restricted to sample scale and is therefore most often only an intermediate step of analysis. Many ecological questions can be addressed either by direct analysis of the variation in species composition using raw data approaches or by further analysis of differentiation datasets on aggregation scale with or without respect to an external gradient.     

A SEASONAL STUDY OF THE VEGETATIVE SHOOT APEX OF MYRIOPHYLLUM HETEROPHYLLUM

The seasonal study of the vegetative shoot apex and its direct derivatives in the dicotyledonous angiosperm Myriophyllum heterophyllum during the production of its 3 leaf types revealed a great similarity in the anatomy of the apex which produced them. The apex consisted of 2 tunica layers and a corpus that varied slightly. The corpus consisted of the corpus initials, the central rib meristem, and the inner layers of the flanking meristem. The work was compared with several works, but in particular with that of Vochting (1872). Vochting worked with another species, M. spicatum, using the terminology of the histogen concept. This work has verified many of Vochting's observations in the light of today's terminology and extends the range of seasonal shoot-apical studies.     

Sexual reproduction: nuclear cycles and life-histories with particular reference to lower eukaryotes

Sexual reproduction is defined as the union of two haploid nuclei each derived from one of two different meioses. The implications of this definition for the interpretation of sexuality in coenocytes and homothallic haploids is discussed. The separation of the concept of the nuclear cycle from that of the life-history is advocated, and a new terminology for the nuclear cycle is proposed. The distinction between the terms life-cycle and life-history is reiterated.