Durham E-Theses The vegetation of the River Tweed N. T. H. Holmes, How to cite: N. T. H. Holmes, (1975) The vegetation of the River Tweed, Durham theses, Durham University. Available at Durham E-Theses Online: http://etheses.dur.ac.uk/8189/ 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 VEGETATION OF THE RIVER TWEED A thesis submitted by N. T. H. Holmes, B.Sc. (Dunelm), to the University of Durham, for the Degree of Doctor of Philosophy Department of Botany, University Science Laboratories, South Road, / Durham. I April, 1975 I 1 I I This thesis, which is entirely the result of my own work, has not been accepted for any degree, and is not being submitted concurrently in . canditature for any other degree. \ \ I i CONTENTS page Abstract I Acknowledgments II 1. INTRODUCTION 1 1.1 Aims 1 1.2 Literature referring to macrophyte surveys in rivers 1 1.3 Environmental parameters regarded as important in affecting the distribution of macrophytes in rivers 4 1.4 Techniques of survey 7 1.5 Problems in collection and interpretation of macrophyte data from rivers 12 1.6 The present study 14 2. METHODS 18 2.1 Collection of background information on the Tweed and tributaries: physical parameters and water chemistry 18 2.11 Physical parameters 18 2.12 Water chemistry - introduction 18 2.13 Sampling programme 18 2.14 Collection and storage of samples 20 2.15 Analyses 21 2.2 Macrophyte surveys 23 2.3 Erection of "association tables" 27 2.4 Terminology 29 3. AREA DESCRIPTION 32 3.1 Introduction 32 3.2 Physical characteristics oi the Tweed and its tributaries 34 3.3 Geology 48 3.4 Climate 50 3.5 Population, industry and sewerage 53 3.51 Introduction 53 3.52 Lanarkshire 56 3.53 Midlothian 56 3.54 Peebles 57 3.55 Selkirkshire 58 3.56 Roxburghshire 60 3.57 Berwickshire 63 3.58 Northumberland 65 3.59 Summary and discussion 65 3.6 Hydrology, and data from the continuous water monitor 70 3.61 Hydrology 70 3.62 Continuous water monitor data 79 4. CHECK LIST OF MACROPHYTES RECORDED IN THE TWEED BASIN 82 4.1 Check list 82 4.11 Introduction 82 4.12 Algae 82 4.13 Lichens 84 4.14 Hepatics 84 4.15 Mosses 85 4.16 Angiosperms 87 4.17 Other macroscopic microbial communities 90 4.2 Taxonomic literature 91 4.21 Algae 91 4.22 Lichens 91 4.23 Bryophytes 91 4.24 Angiosperms 91 4.3 Verification of taxonomy 92 5. CHEMISTRY OF THE TWEED BASIN 93 5.1 Introduction 93 5.2 Chemical data 95 5.21 Primary data from five surveys 96 5.22 Element means for the four lowest flows 115 5.23 Diagrams of element levels throughout the Tweed 118 5.24 Data from 20 additional sites 122 5.3 Summary of the water chemistry of the River Tweed 123 5.4 Summary of the water chemistry of tributaries 128 6. PRIMARY DATA 134 6.1 Introduction 134 6.2 Complete surveys 136 6.21 Tweed 136 6.22 Teviot 167 6.3 Partial surveys 181 6.4 Distribution patterns of individual speedes 200 6.41 In each 10 km of the Tweed 200 6.42 Overall distribution in Tweed Basin 209 6.5 Relationship of abundance values to presence or absence technique 221 7. SUMMARY OF THE DISTRIBUTION AND ECOLOGY OF INDIVIDUAL MACROPHYTES 225 7.1 Introduction 225 7.2 Descriptive accounts 226 7.21 Algae 227 7.22 Lichens 255 7.23 Bryophytes 259 7.24 Angiosperms 304 7.25 Other macroscopic microbial communities 369 7.3 Photographs of 12 species 370 8. POPULATION DESCRIPTION, MACROPHYTE COMMUNITIES 372 8.1 Introduction 372 8.2 River Tweed 376 8.21 Total abundance changes throughout the river 376 8.^2 Relationship of total abundance to the relative numbers and abundances of algae, lichens, bryophytes and angiosperms 376 8.23 Macrophyte communities 378 8.3 River Teviot 380 8.31 Total abundance changes throughout the river 380 8.32 Relationship of total abundance to the relative numbers and abundances of algae, lichens, bryophytes and angiosperms 8.33 Macrophyte communities 381 8.4 Partially surveyed tributaries 382 8.41 Biggar Water 382 8.42 Lyne Water 383 8.43 Yarrow Water 384 8.44 Ettrick Water 385 5.45 Jed Water 387 8.46 Eden Water 387 8.47 Leet Water 388 8.48 River Till 389 8.49 Adder Waters 390 8.5 Summary 393 8.6 Figures 397 8.61 Total abundance histogram 398 8.62 Number of species in each taxa, per 10 km stretch of river 399 8.63 Relative abundances of each taxa, per 10 km stretch of river 401 8.64 "Association tables" 405 9. SUMMARY AND DISCUSSION 407 9.1 Introduction 407 9.2 The distribution of species in relation to environmental parameters 410 9.21 Physical characteristics 410 9.22 Water chemistry 420 9.3 Comparison with macrophyte surveys of other rivers 431 9.31 Rivers in N-E. England 431 9.32 Other rivers in England 438 9.33 Rivers in mainland Europe 444 9.4 Comparison with literature on environmental parameters 449 9.41 Physical factors 449 9.42 Water chemistry 452 9.43 Other parameters 45? 9.5 Classification of plant communities 453 9.6 Concluding remarks 461 9.7 Tables 464 BIBLIOGRAPHY 473. ABSTRACT A detailed account is given of the wacropuytic vegetation of the major rivers within the Tweed Basin. Of these rivers, the Tweed and its largest tributary, the Teviot, "have been studied in most detail, both being surveyed from source to mouth. Information brought together on the history and physiography of the Tweed Basin are summarized in this account, together with physical and water chemical data collected during the survey. The distribution of species is discussed in relation to changes in such parameters. The method of survey involved recording the presence or absence of all macrophytic species within 0.5 km lengths of river, together with a subjective evaluation of their abundance. 570 such 0.5 km lengths were surveyed. All macroscopically visable species were recorded which were found completely submerged or at the immediate edge of the river. A total of 180 different macrophytic growths ( usually species, but occasionally identified only to genus level ) were present in the basin, including: 31 algae, 5 lichens, 83 bryophytes, 59 angiosperms, 2 macroscopic microbial communities. The identification and taxonomy of all species were studied critically. Environmental parameters collected in most detail were the physical characteristics of each river, such as altitude, features of the substratum and flow regime. A water sampling programme was undertaken which involved the collection of 5 duplicate samples from sites in the main river and tributaries, and subsequent analysis for optical density, pH, conductivity, 10 cations and 6 anions. The final discussion includes an appraisal of literature concerned ' with macrophytes in rivers, methods of study, and results obtained. Particular attention is paid to floristic accounts, especially those fron the neighbourhood of the Tweed, the floras of these rivers being compared with the flora of the Tweed Basin. Comparison with data from these surveys would suggest that the Tweed is a river which is especially rich in macrophyte species. The presence of historical data and herbarium specimens collected over the past two centuries has made it possible to suggest tentatively that the distribution of some species has changed markedly, whereas others appear to have changed little over 150 years. Cladophora 8. , glomerata is an example of/species which in recent years has become much less abundant. This is most probably due to a decrease in total phosphate content in. the water, this in turn being due to a reduction in the use of synthetic detergents by the textile industry. I ACKNOWLEDGMENTS I wish to thank Professor D. Boulter for the provision of research facilities in the Department of Botany, University of Durham for the duration of the project. To all the staff of the Tweed River Purification Board, and in particular Mr J. C. Currie, sincere thanks are due for constant assistance in all spheres of my work throughout the three years of research, and also for supplying recent chemical and hydrological data. I should also like to thank Col. J. Ryan, Chairman of the Tweed Commissioners for hours of helpful discussions and access to Old Pollution and Fisheries Commissioners Reports. To the Biagi family, special thanks are due for allowing me and my samples to take over their home during survey periods. Thanks are due to those who have helped in problems of taxonomy. The referees for particular taxa which are listed in 4.3 are thanked most sincerely: in particular, thanks are due to Rev. G. G. Graham for hours of helpful discussions and many critical identifications of bryophyte species: to Mr J.