Fuzzy systems vegetation theory

Fuzzy systems vegetation theory is a comprehensive framework for the expression of vegetation theory and conceptual models, as well as the development of vegetation analyses. It is applicable to vegetation/environment relations, vegetation dynamics, and the effects of environmental dynamics on vegetation composition. Fuzzy systems vegetation theory is a fuzzy set generalization of dynamical systems theory and incorporates a formal logic and mathematics. This paper presents the elements of fuzzy systems vegetation theory and discusses the relationship of the fuzzy systems theory to the geometric concepts generally employed in vegetation theory.     

A dynamical systems perspective on the relationship between symbolic and non-symbolic computation

It has been claimed that connectionist (artificial neural network) models of language processing, which do not appear to employ “rules”, are doing something different in kind from classical symbol processing models, which treat “rules” as atoms (e.g., McClelland and Patterson in Trends Cogn Sci 6(11):465–472, 2002). This claim is hard to assess in the absence of careful, formal comparisons between the two approaches. This paper formally investigates the symbol-processing properties of simple dynamical systems called affine dynamical automata, which are close relatives of several recurrent connectionist models of language processing (e.g., Elman in Cogn Sci 14:179–211, 1990). In line with related work (Moore in Theor Comput Sci 201:99–136, 1998; Siegelmann in Neural networks and analog computation: beyond the Turing limit. Birkhäuser, Boston, 1999), the analysis shows that affine dynamical automata exhibit a range of symbol processing behaviors, some of which can be mirrored by various Turing machine devices, and others of which cannot be. On the assumption that the Turing machine framework is a good way to formalize the “computation” part of our understanding of classical symbol processing, this finding supports the view that there is a fundamental “incompatibility” between connectionist and classical models (see Fodor and Pylyshyn 1988; Smolensky in Behav Brain Sci 11(1):1–74, 1988; beim Graben in Mind Matter 2(2):29--51,2004b). Given the empirical successes of connectionist models, the more general, super-Turing framework is a preferable vantage point from which to consider cognitive phenomena. This vantage may give us insight into ill-formed as well as well-formed language behavior and shed light on important structural properties of learning processes.     

Successive mapping of dune slack vegetation

Summary The succession of the dune slack vegetation around an artificial lake was studied by means of successive mapping. A succession scheme was prepared on the basis of comparison of the maps made in various years. This scheme was discussed in terms of systems theory, with reference to a kinematic graph prepared on the basis of the transformations. The succession derived from the vegetation maps was compared with that derived from the permanent plots; the results of this comparison indicated that only a small proportion of the total number of succession lines could be detected with the aid of the permanent plots. In addition, the information that could be derived from the permanent plot analysis depended on the degree of change of the vegetation in the area; more information could be derived from drier areas which showed the least degree of change. The best method for the investigation of the succession proved to be a combination of a restricted number of permanent plots and successive mapping. Nomenclature of species follows Heukels-van Ooststroom Flora van Nederland, 16 ed. 1970. R.I.N.-Comm. nr. 107.     

A vegetation map of The Netherlands,based on the relationship between ecotopes and types of potential natural vegetation

Summary The method of mapping the vegetation on scale 1: 200,000 and the starting points in relation to the potential natural vegetation and ecotopes, are discussed.In view of the planological background of this study, some restrictions have been added to the concept of potential natural vegetation, concerning the period of development and the human influence.The relationship between soil, ground water and vegetation was studied, which resulted in the map of the potential natural vegetation.Each type of potential natural vegetation stands for a series of vegetation types on the same site. Seven main series, with a number of sub-series are distinguished. Within each vegetation series the plant communities have been spread over five groups, according to their structure and naturalness.Ecotopes and ecotope complexes are considered as landscape ecological units. A list of ecotopes was obtained by interpreting topographical maps and by inventory data.The actual vegetation was mapped by estimating the size of the ecotopes within the separate areas. It was expressed in a five figure code for the five groups from the vegetation and ecotopes is combined into the vegetation map of The Netherlands.Interpretation problems, some of them specific for The Netherlands, are discussed and some remarks are made on the necessity of further research.Contribution to the Symposium on Plant Species and Plant Communities, held at Nijmegen, 11–12 November 1976, on the occasion of the 60th birthday of Professor Victor Westhoff.Nomenclature follows Heukels-van Ooststroom, Flora van Nederland, 18e druk, 1975, Wolters-Noordhoff, Groningen; nomenclature of syntaxa follows Westhoff & den Held (1969)     

A cluster analysis based on graph theory

Summary A clustering method is presented that groups sample plots (stands or other units) together, based on their proximity in a multidimensional test space in which the axes represent the attributes (species) of the individuals (sample plots, etc.). The resulting dendrogram is used to make subjective judgements on the type and distinctiveness of the groupings. The method is demonstrated on the vegetation data from 43 sample plots in mixed white spruce stands in Saskatchewan. The results were related to the levels of 31 habitat variables. Significant differences among the groups were shown to exist for basal area, height growth, and root penetration of white spruce and for field capacity and pH of the soil. When possible the nomenclature of Fernald (1950) is followed for the Pteridophyta and Spermatophyta; elsewhere Rydberg's (1954) nomenclature is followed. The nomenclature of Grout (1928–1940) is used for the Musci, with the exception ofCalliergonella schreberi, which is replaced byPleurozium schreberi (Willd) Mitt.     

A vegetation-ecological approach to the classification and evaluation of potential natural vegetation of the Fagetea crenatae region in Tohoku (northern Honshu), Japan

A new vegetation-ecological approach is proposed for classification and evaluation of vegetation zones by means of phytosociological landscape analysis, based on the potential natural vegetation. The study area is the “Fagetea crenatae region” of the cool-temperate zone of Tohoku (northern Honshu) and the northern parts of Kanto. The area was divided into 953 geographic quadrats on a base map at a scale of 1 ∶ 500000. Based on climax complexes of vegetation in each quadrat, 55 community sub-groups were distinguished as basic units of community complex and vegetation landscapes. The community sub-groups were then grouped into 17 larger community groups by the phytosociological table method. As a result, three phytogeographic vegetation zones (Japan Sea side, inland areas and Pacific side) were classified. For each of these community sub-groups, five geographical and climatic variables (average altitude, mean annual temperature, Kira's warmth index, annual precipitation and mean annual maximum snow depth) were averaged, and the community sub-groups in the same community group, which resembled each other ecologically, were assembled into 28 clusters. The clusters were combined into 11 ecological groups by means of Pearson's similarity ratio of geographical and climatic characteristics. By comparing these ecological groups as a vegetation complex, four phytogeographic vegetation zones (Japan Sea side, inland areas, Pacific side and northern Honshu) corresponding to each potential natural vegetation region with distinct environmental characteristics, were newly classified.     

辽宁西部低山丘陵区植被恢复研究：基于演替理论和生态系统退化程度

在对辽宁西部地区植被演替分析的基础上,选用不同演替阶段的生境指标,应用聚类分析方法,定量确定了辽宁西部低山丘陵区退化生态系统的退化程度．在辽宁西部地区,南刘杖子林场的天然栎林、天然油松林、杨栎林、牛河梁和欺天林场坡地的人工油松林与天然松栎林的平均相异系数分别为0．655、0．665、2．029、3．919,综合反映了其在生态系统演替／退化中的相对位置．研究表明。辽宁西部低山丘陵区现有油松林(阴坡)立地大多已退化到灌木林和先锋乔木林之间的演替阶段,并且接近于先锋乔木林阶段;建议在现有人工林经营改造或营造混交林时,应适当增大灌木树种和先锋乔木树种的比重．     

基于夜间灯光数据的甘青宁城市扩展及其建成区植被变化特征

开展针对黄河上游甘青宁地区城市建成区空间发展模式及其植被变化特征的研究,可为构建科学合理的城市发展体系、维护区域生态安全屏障提供重要的参考依据。以DMSP/OLS和统计数据为基础,运用统计数据比较法提取了甘青宁地区21座地级市(州)的城市建成区边界,并从城市空间扩展特征、扩展速度、动态度、紧凑度和重心迁移5个方面对城市扩展特征进行分析;在此基础上,引入SPOT/VEGETATION NDVI数据,以年均NDVI作为表征城市建成区植被状况的指标,从NDVI总和、均值、比值及其变化量、年际变化率及其变化百分率和稳定性5个方面对研究区2002—2013年城市建成区的植被变化进行研究。结果表明：1)采用统计数据比较法提取获得的研究区城市建成区精度较高,误差率在6.7%以内;2)城市用地围绕河西走廊及黄河上游地区形成不连续的“几”字型空间形态,并具有点状、线状和面状3种不同的分布模式;3)城市扩展年均速及动态度大体呈上升趋势,且2010—2013年的城市扩展速度(4.53 km~2/a)是2006—2010年的2倍;4)除酒泉、海西、白银、天水、石嘴山和兰州外,其他城市建成区紧凑度指数均较高;5...     

A perspective on Peter Mitchell and the chemiosmotic theory

In 1991 Peter Mitchell wrote a last article that summarised his views on the origin, development and current status of his chemiosmotic ideas. I here review some of his views of that time on structures and mechanisms of several key bioenergetic components in relation to the subsequent advances that have been made.     

A new practical tool for deriving a functional signature for herbaceous vegetation

Hypothesis: For any one time and place a ‘functional signature’ can be derived for a sample of herbaceous vegetation in a way that concisely represents the balance between the different clusters of functional attributes that are present among component species. Methods: We developed a spreadsheet‐based tool for calculating functional signatures within the context of the C‐S‐R system of plant functional types. We used the tool to calculate and compare signatures for specimen British vegetation samples which differed in management regime and location in time. Conclusion: The integrative power of the ‘C‐S‐R signature’ is useful in comparative studies involving widely differing samples. Movements in the signature can be used to indicate degree of resistance, resilience, eutrophication and dereliction. Systems of plant functional types other than C‐S‐R might also be approached in this way. Availability: The tool can be downloaded free of charge from the first author's web pages or from the journal's electronic archive.     

A density functional theory study on the Ti/P binary cluster ions

Under the framework of density functional theory, an all-electron calculation on the geometrical structures and dissociation channels of Ti/P binary cluster ions has been carried out. The P₂, P₃ and P₄ structures are found to be the relatively stable units in these cluster ions. The lowest energy geometries of these Ti/P binary cluster ions may be constructed by bonding Ti, Ti₂, Ti₃ or Ti₄ unit with one or two relatively stable P₂, P₃ and P₄ units. The most possible dissociation channels of these Ti/P binary cluster ions are the detachment of P₂, P₃ or P₄ fragment. It is well consistent with the photodissociation experimental results.