The Phytosociology of Calcareous Grasslands in the British Isles
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Durham E-Theses The phytosociology of calcareous grasslands in the British Isles Shimwell, David William How to cite: Shimwell, David William (1968) The phytosociology of calcareous grasslands in the British Isles, Durham theses, Durham University. Available at Durham E-Theses Online: http://etheses.dur.ac.uk/9653/ Use policy The full-text may be used and/or reproduced, and given to third parties in any format or medium, without prior permission or charge, for personal research or study, educational, or not-for-prot purposes provided that: • a full bibliographic reference is made to the original source • a link is made to the metadata record in Durham E-Theses • the full-text is not changed in any way The full-text must not be sold in any format or medium without the formal permission of the copyright holders. Please consult the full Durham E-Theses policy for further details. Academic Support Oce, Durham University, University Oce, Old Elvet, Durham DH1 3HP e-mail: [email protected] Tel: +44 0191 334 6107 http://etheses.dur.ac.uk THE PHYTOSOCIOLOGY OF CALCAREOUS GRASSLANDS IN THE BRITISH ISLES by David William Shimwell (B.Sc. Dunelm) being a thesis submitted for the degree of Doctor of Philosophy in the University of Durham. September 1968. s« 3 HAY M9 To the best of my knowledge, and apart from any text references to published works, the content of this thesis is entirely my own research, and has not been previously submitted for any degree or diploma. DAVID W. SHIMWELL, September 1968. -III- ABSTRACT The thesis attempts a broad overall survey and classi• fication according to the Zurich-Montpellier system of plant sociology, of limestone grassland vegetation in the British Isles. The classification is based on some 535 grassland Aufnahmen and 75 Aufnahmen of contact communities. In all, some 13 grassland Associations are recognised, whilst the zonal and successional communities are classified in 16 Associations. The Associations are classified in the system of classification advocated by Lohmeyer ejt al. (1962), and the phytogeographical relationships of the related Association-groups or Alliances are considered in detail. The limestone grassland communities of the British Isles have been found to be representative of four Classes:- (a) Festuco-Brometea - thermophilous dry grassland communities of the sub-mediterranean and sub-atlantic regions of Europe; (b) El^no-Seslerietea - dry sub-montane, sub-alpine grass heaths of the low alpine region of central Europe and Scandinavia; (c) Molinio-Arrhenatheretea - mesophilous, grazed or mown hay meadows and pastures of the lowland zone of western Europe; (d) Violetea_calaminariae - open grassland communities -IV- of heavy metal-rich strata and spoil banks. The thesis is divided into 5 parts:- Part 1 reviews the methods available for a vegetation survey and phytosociological technique in general; outlines the history and status of limestone grasslands; and summarises the methods used for previous description of British vegetation; Part 2 presents the results of the grassland survey and relates the change in overall floristic composition and grassland type to climatic factors using the climate diagrams of Walter & Lieth (1967); Part 3 considers the successional and zonal relationships of these grassland communities, whilst Part 4 discusses the validity of the methods used for the survey and suggests some of the logical extensions of this work with reference to the conservation and management of an area limestone grassland on the Magnesian Limestone of Co. Durham. Part 5 comprises 36 Association Tables and an Aufnahmen locality Appendix, and is to be found in the folio volume. References LOHMEYER, W. et al. (1962). Contribution a 1'unification du systeme phytosociologique pour 1*Europe moyenne et nord-occidentale. Melhoramento, 15, 137-151. -V- WALTER, H. & LEITH, H. (1967). Klimadiagramm Weltatlas. Jena. -VI- Foreword The following references have been used for the nomenclature of species:- Flowering plants and ferns - Dandy, J. E. (1958). List of British Vascular Plants. Br. Mus. Nat. Hist., London Mosses - Warburg, E. F. (1963). Census Catalogue of British Mosses (3rd ed.). Brit. Bryol. Soc. Publ., Ipswich; Liverworts - Paton, J. A. (1965). Census Catalogue of British Hepatics (4th ed.). Brit. Bryol. Soc. Publ., Ipswich; Lichens - James, P. W. (1967). A New Check-list of British Lichens. The Lichenologist, Vol. 3, 95-153. Any deviations from these systems are noted in the text. Part I of the thesis reviews some of the available phytosociological techniques and the history of their appli• cation to British vegetation, and considers many of the back• ground problems associated with a survey of limestone grass• lands. Part 2 comprises the results of this survey. In order to make the details as explicit as possible, a set format is adhered to throughout this section. The Zurich- Montpellier system of classification as advocated by Lohmeyer et al. (1962) is used as the framework, and brief descriptions are given for each of the levels of classification, e.g. Class, Order and Alliance. Within each Alliance, the -VII- Associations are described in the following manner:- 1. Synonymy - names given by previous authors to the grasslands in question. 2. Habitat details - (a) Geographical and altitudinal distribution; (b) Climate - related as far as possible to the climate-types described by Walter 8s Lieth (1967); (c) Topographical limitations; (d) Soils. 3. Characteristics of the Association - details of the floristic composition and community structure of the Association and its constituent Sub-associations. 4. Zonation and Succession - the relationship of the Association to other plant communities, (see also Part 3, Chapter 5). With the appropriate Association Table and the Limestone Grassland 'Matrix Diagram' (see Volume 2) at hand, the interpretation of the text is straightforward. For each Alliance, the phytogeographical relationships of their constituent Associations are considered - (a) within the British Isles; (b) in western Europe. This general approach is considered to be the most appropriate and most explicit method of presentation of the basic data for readily available reference purposes. -VIII- In Part 4, the value of a broad phytosociological survey is discussed and some of the logical extensions of this work are illustrated with reference to the conservation of areas of Magnesian Limestone grassland in Co. Durham. -o-o-o-O-o-o-o- In the text, all Latin species names and all other names in italics are underlined with a continuous line. The names of Alliances, Associations, Noda etc., are underlined with a broken line. -IX- ACKNOWLEDGEMENTS I wish to thank Dr. D. J. Bellamy for his constant enthusiasm during the three years research and his criticism of the manuscript; Professor R. Tuxen for his guidance and generosity during my stay at Todenmann, West Germany, and for permission to include unpublished data; Father J. J. Moore S.J. for explaining some of the finer points of the Z-M system of plant sociology; Dr. R. F. McKee, Messrs. P. Bridgewater, D. Welch and T. C. E. Wells, for making available unpublished data; Professors D. H. Valentine and D. Boulter on whose department the research was based; The Natural Environment Research Council for a Research Studentship for the three years of research; the Cement Marketing Board for an additional grant to provide transport for the research; Miss M. Berryman for her perseverance and efficiency in the typing of the thesis; Mr. A. Jamieson for his help in the reproduction of text figures; my parents for providing transport during the first field season and the initial opportunities for the project; and to my wife for her help with the preparation of the phytosociological tables and for her forbearance throughout. CONTENTS Part I. Chapter 1: A commentary on the present state of phytosociology in the British Isles 1 Chapter 2: Limestone grasslands: their history and status 8 Chapter 3: The history of the description of British vegetation and the application of the Zurich-Montpellier system of plant sociology 19 Part II. Chapter 4: A classification of the limestone grasslands of the British Isles 29 Synopsis of Classification 30 (A) Class Festuco-Brometea 31 Order Brometalia erecti 35 (a) Alliance Bromion 42 Sub-Alliance Xerobromion 44 Association Poterio-Koelerietum vallesianae 47 Helianthemum apenninum-Euphorbia portlandica Nodum 55 The phytogeographical relationships of the British Association of Alliance Bromion 58 (b) Alliance Mesobromion 65 Sub-Alliance Eu-Mesobromion 68 Association Cirsio-Brometum 69 Helictotricho-Caricetum flaccae 80 Helianthemo-Koelerietum 88 Caricetum montanae 96 Antennarietum hibernicae 101 Camptothecio-Asperuletum cynanchicae 106 Sub-Alliance Seslerio-Mesobromion 110 Association Seslerio-Helictotrichetum Ill Seslerio-Caricetum pulicariae . 118 Asperulo-Seslerietum 128 The phytogeographical relationships of the Associations of the Alliance Mesobromion 136 (B) Class Elyno-Seslerietea 153 Order Elyno-Dryadetalia 154 Alliance Potentilleto-Polygonion vivipari 155 Alliance Kobresio-Dryadion 155 Association Plantagino-Dryadetum 157 Salico-Dryadetum 161 The phytogeographical relationships of the Association of the Alliance Kobresio- Dryadion 164 (C) Class Molinio-Arrhenatheretea 166 Order Molinietalia coeruleae 168 Order Arrhenatheretalia elatioris 170 Alliance Cynosurion cristati 171 Association Centaureo-Cynosuretum 172 Alliance Arrhenatherion elatioris 173 Association Centaureo-Arrhenathereturn 174