https://www.wsl.ch/staff/niklaus.zimmermann/papers/ecomod135_147.pdf

Predictive habitat distribution models in ecology

It is suggested that evolution in plants may be associated with the emergence of three primary strategies, each of which may be identified by reference to a number of characteristics including morphological features, resource allocation, phenology, and response to stress. The competitive strategy prevails in productive, relatively undisturbed vegetation, the stress-tolerant strategy is associated with continuously unproductive conditions, and the ruderal strategy is characteristic of severely disturbed but potentially productive habitats. A triangular model based upon the three strategies may be reconciled with the theory of r- and K-selection, provides an insight into the processes of vegetation succession and dominance, and appears to be capable of extension to fungi and to animals.

Evidence for the existence of three primary strategies in plants and its relevance to ecological and evolutionary theory

SUMMARY
1According to ‘Gause's hypothesis’ a corollary of the process of evolution by natural selection is that in a community at equilibrium every species must occupy a different niche. Many botanists have found this idea improbable because they have ignored the processes of regeneration in plant communities.
2Most plant communities are longer-lived than their constituent individual plants. When an individual dies, it may or may not be replaced by an individual of the same species. It is this replacement stage which is all-important to the argument presented.
3Several mechanisms not involving regeneration also contribute to the maintenance of species-richness:


(a). differences in life-form coupled with the inability of larger plants to exhaust or cut off all resources, also the development of dependence-relationships,
(b) differences in phenology coupled with tolerance of suppression,
(c) fluctuations in the environment coupled with relatively small differences in competitive ability between many species,
(d) the ability of certain species-pairs to form stable mixtures because of a balance of intraspecific competition against interspecific competition,
(e) the production of substances more toxic to the producer-species than to the other species,
(f) differences in the primary limiting mineral nutrients or pore-sizes in the soil for neighbouring plants of different soecies, and
(g) differences in the competitive abilities of species dependent on their physiological age coupled with the uneven-age structure of many populations.


4The mechanisms listed above do not go far to explain the indefinite persistence in mixture of the many species in the most species-rich communities known.
5In contrast there seem to be almost limitless possibilities for differences between species in their requirements for regeneration, i.e. the replacement of the individual plants of one generation by those of the next. This idea is illustrated for tree species and it is emphasized that foresters were the first by a wide margin to appreciate its importance.
6The processes involved in the successful invasion of a gap by a given plant species and some characters of the gap that may be important are summarized in Table 2.
7The definition of a plant's niche requires recognition of four components:


(a) the habitat niche,
(b) the life-form niche,
(c) the phenological niche, and
(d) the regeneration niche.


8A brief account is given of the patterns of regeneration in different kinds of plant community to provide a background for studies of differentiation in the regeneration niche.
9All stages in the regeneration-cycle are potentially important and examples of differentiation between species are given for each of the following stages:


(a) Production of viable seed (including the sub-stages of flowering, pollination and seed-set),
(b) dispersal, in space and time,
(c) germination,
(d) establishment, and
(e) further development of the immature plant.


10In the concluding discussion emphasis is placed on the following themes:


(a) the kinds of work needed in future to prove or disprove that differentiation in the regeneration niche is the major explanation of the maintenance of species-richness in plant communities,
(b) the relation of the present thesis to published ideas on the origin of phenological spread,
(c) the relevance of the present thesis to the discussion on the presence of continua in vegetation,
(d) the co-incidence of the present thesis and the emerging ideas of evolutionists about differentiation of angiosperm taxa, and
(e) the importance of regeneration-studies for conservation.

The maintenance of species-richness in plant communities: the importance of the regeneration niche

There is considerable debate about whether community ecology will ever produce general principles. We suggest here that this can be achieved but that community ecology has lost its way by focusing on pairwise species interactions independent of the environment. We assert that community ecology should return to an emphasis on four themes that are tied together by a two-step process: how the fundamental niche is governed by functional traits within the context of abiotic environmental gradients; and how the interaction between traits and fundamental niches maps onto the realized niche in the context of a biotic interaction milieu. We suggest this approach can create a more quantitative and predictive science that can more readily address issues of global change.

/pdf/rebuilding-community-ecology-from-functional-traits-3zvmk5wnvd.pdf

Rebuilding community ecology from functional traits.

Studies by ourselves and others (Swan 1970, Austin & Noy-Meir 1972, Beals 1973, Hill 1973, 1974, Austin 1976a, b, Fasham 1977, Gauch Whittaker & Wentwarth 1977, Noy-Meir & Whittaker 1977, Orloci 1978, Gauch, Whittaker & Singer 1979) have found faults with all ordination techniques currently in use, at least when applied to ecological data specifying the occurrences of species in community samples. These faults certainly do not make existing techniques useless; but they mean that results must be interpreted with caution. Even with the best techniques, the underlying structure of the data is often poorly expressed.

Detrended correspondence analysis: an improved ordination technique

Aims and methods of vegetation ecology , Aims and methods of vegetation ecology , مرکز فناوری اطلاعات و اطلاع رسانی کشاورزی

Aims and Methods of Vegetation Ecology

/pdf/zeigerwerte-von-pflanzen-in-mitteleuropa-47ay6eolup.pdf

Zeigerwerte von Pflanzen in Mitteleuropa

Vegetation Mitteleuropas mit den Alpen

Foreword Preface to the first edition Preface to the second edition Preface to the third and fourth editions Part I. Introductory Survey: 1. The vegetation of Central Europe in general 2. The development of the plant cover under the influence of man Part II. Near-natural woods and thickets: 1. General view of the central European woodlands 2. Beech and mixed beech woods 3. Other deciduous woodland excluding flood plains and mires 4. Coniferous woodland and mixed woods dominated by conifers 5. Tree and shrub vegetation of flood plains and peat lands Part III. Other Near-Natural Formations: 1. The vegetation of fresh water, its banks and springs 2. Woodland fens and intermediate mires compared with other mire types 3. Raised bogs and the communities connected with them 4. Sea marshes and inland saline habitats 5. Dunes and their vegetation successions 6. The vegetation above the alpine tree line 7. Plant life in the region of eternal snow 8. On the epiphytic vegetation in central Europe Part IV. Formations Created and Maintained Largely by Man's Activities: 1. Arid and semi-arid grasslands in colline and monotane climate 2. Dwarf-shrub heaths and commons on strongly acid soils 3. Forestry plantations and woodland clearings 4. Woodland edges, bushes, hedges and their barbarous margins 5. Hay and litter meadows 6. Manured pastures, trodden swards and those subject to flooding 7. Man-influenced vegetation of muddy ground, lakesides and banks 8. Ruderal communities of drier sites 9. Weed communities of arable land, gardens and vineyards 10. Vegetation development on abandoned land Tabular summary and index: Bibliography Remarks on the changes in the system of plant sociology Summary of the vegetation units and species Subject Index.

Heinz Ellenberg

Papers

Aims and Methods of Vegetation Ecology

Zeigerwerte von Pflanzen in Mitteleuropa

Vegetation Mitteleuropas mit den Alpen

Vegetation Ecology of Central Europe

Vegetation Ecology of Central Europe.