ISSN 0466 6054 NATURE IN WALES Volume 17 Part 1, March 1980 CONTENTS Editorial 2 Articles 4 The Status of Breeding Wildfowl in Wales by R. Lovegrove, R.A. Hume and I. McLean 4 Control of Air Pollution at Pembroke Power Station by R. T. Jarman and C. M. de Turville 12 Cotoneaster integerrimus a Conservation Exercise by M. Morris 19 Issues in Conservation 23 Vegetational Succession and Climax Communities by D. Gregson 23 Dyfed Wildlife Appeal by I. Watt 28 Environment and Wildlife 32 Hedgecraft by M. Sykes 32 Castle Woods in February by H. Sealy-Lewis 37 Profile of Dillwyn Miles by J. W. Donovan 39 Country Diary by David W. Evans 41 Short Notes 43 An Estimate of the Numbers of Shearwaters on the Neck, Skomer, 1978 by M. Alexander and C. M. Perrins 43 Gagea bohemica-a new British Record by F.M. Slater 47 Comment Upland Forestry-Threat or Opportunity? by R. Lovegrove 48 Field Notes 51 In Brief 55 Book Reviews 57 General 57 About Wales 62 For Younger Readers 62 Letters to the Editor 63