Natural England Commissioned Report NECR151 Assessing and addressing the impacts of ash dieback on UK woodlands and trees of conservation importance (Phase 2) First published 30 April 2014 www.naturalengland.org.uk Foreword Natural England commission a range of reports from external contractors to provide evidence and advice to assist us in delivering our duties. This report has been jointly funded by Defra, Department of the Environment Northern Ireland, Forestry Commission, Scottish Natural Heritage and Natural Resources Wales. Background Ash dieback (or ‘Chalara’), is the fungal tree disease • Develop management options and to assess which is increasingly affecting ash (Fraxinus changes in woodland composition following excelsior) trees in the UK. Ash trees are important for infection of ash dieback in the 9 ash-relevant biodiversity and ash dieback could affect biodiversity regions of the UK. with consequences for species conservation through • Evaluate the short and long term impacts on ash to impacts on woodland ecosystem health. Deciding related biodiversity of ash dieback. how to manage woodlands infected by ash dieback that also conserves biodiversity is an important issue. Develop resources (tools and case studies) for woodland managers. The aim of this project is to assess the potential ecological impact of ash dieback on UK woodlands This report details the second phase of the work. The and species and to investigate possible woodland report relating to phase 1 can be found here. management options which might ameliorate the problems caused. In particular to: This report should be cited as: • Identify the ecological function of ash MITCHELL, R.J., BROOME, A., HARMER, R., (decomposition, litter quality, nutrient cycling). BEATON, J.K., BELLAMY, P.E., BROOKER, R.W., • Identify the ecological function of 11 alternative RAY, D., ELLIS, C.J., HESTER, A.J., HODGETTS, species that might replace ash and compare their N.G., IASON, G.R., LITTLEWOOD, N.A., functioning to ash. MACKINNON, M. PAKEMAN, R., POZSGAI, G., • Identify ash-associated species and their level of RAMSEY, S., RIACH, D., STOCKAN, J.A., TAYLOR, association with ash. A.F.S. & WOODWARD, S. 2014. Assessing and addressing the impacts of ash dieback on UK • Assess the suitability of alternative tree species. woodlands and trees of conservation importance (Phase 2). Natural England Commissioned Reports, The results have been and will continue to be used to Number 151. help: Natural England Project Manager - Christine Reid, Peterborough - Suite D, Unex House, Bourges Boulevard, Peterborough, PE1 1NG [email protected] Contractor - The James Hutton Institute, Craigiebuckler, Aberdeen, AB14 8QH and Forest Research Keywords - Ash dieback, biodiversity loss, Chalara, Chalara fraxinea, emerging diseases, forest pathology, fungal pathogens, Fraxinus excelsior, ash, ecological impacts, species, Hymenoscyphus pseudoalbidus, alternative trees, tree diseases Further information This report can be downloaded from the Natural England website: www.naturalengland.org.uk. For information on Natural England publications contact the Natural England Enquiry Service on 0845 600 3078 or e-mail [email protected]. This report is published by Natural England under the Open Government Licence - OGLv2.0 for public sector information. You are encouraged to use, and reuse, information subject to certain conditions. For details of the licence visit www.naturalengland.org.uk/copyright. Natural England photographs are only available for non commercial purposes. If any other information such as maps or data cannot be used commercially this will be made clear within the report. ISBN 978-1-78354-125-6 © Natural England and other parties 2014 Acknowledgements: We thank Peter Buckley, Keith Kirby and Marco Pautasso for peer reviewing the report. This project was kindly granted access to the TRY, Bioflor, Leda and PlantAtt databases for plant traits. The TRY initiative on plant traits (http://www.trydb.org) is hosted, developed and maintained by J. Kattge and G. Bönisch (Max-Planck-Institute for Biogeochemistry, Jena, Germany).TRY is/has been supported by DIVERSITAS, IGBP, the Global Land Project, the UK Natural Environment Research Council (NERC) through it’s program QUEST (Quantifying and Understanding the Earth System), the French Foundation for Biodiversity Research (FRB), and GIS "Climat, Environnement et Société" France. Chris Preston from the Centre for Ecology and Hydrology granted permission to use and publish data from the PlantAtt database http://www.ceh.ac.uk/products/publications/plantatt- attributesofbritishandirishplantsstatussizelifehistorygeographyandhabitats.html. Michael Kleyer gave permission for data from LEDA database to be used: Kleyer, M., Bekker, R.M., Knevel, I.C., Bakker, J.P, Thompson, K., Sonnenschein, M., Poschlod, P., Van Groenendael, J.M., Klimes, L., Klimesová, J., Klotz, S., Rusch, G.M., Hermy, M., Adriaens, D., Boedeltje, G., Bossuyt, B., Dannemann, A., Endels, P., Götzenberger, L., Hodgson, J.G., Jackel, A-K., Kühn, I., Kunzmann, D., Ozinga, W.A., Römermann, C., Stadler, M., Schlegelmilch, J., Steendam, H.J., Tackenberg, O., Wilmann, B., Cornelissen, J.H.C., Eriksson, O., Garnier, E., Peco, B. (2008): The LEDA Traitbase: A database of life-history traits of Northwest European flora. Journal of Ecology 96: 1266-1274. Stefan Klotz granted permission to use the Bioflora data base http://www2.ufz.de/biolflor/index.jsp. The James Hutton Institute led the project and was the main author of Chapters 1, 2, 3, 4, 6, and 8. Expertise on individual taxa was provided by: Royal Botanic Garden Edinburgh for lichens, Hodgetts - Independent Consultant for bryophytes, University of Aberdeen and the James Hutton Institute for fungi, RSPB for birds and the James Hutton Institute for invertebrates and mammals. Forest Research was the main author of Chapters 5 and 7 and of the case studies which are published separately from this report. The James Hutton Institute led the production of the AshEcol spreadsheets which are also published separately. The worked was funded by a consortium of Defra, Natural England, Scottish Natural Heritage, Natural Resources Wales, Northern Ireland Environment Agency and the Forestry Commission. The project received advice from representatives of the funding bodies: J. Hubert (Forestry Commission), C. Reid and E. Goldberg (Natural England), J. Hall (Scottish Natural Heritage), L. Howe (Natural Resources Wales), J. Farren (Northern Ireland Environment Agency) and H. Pontier, J. Vanderpump, A. Stott and D. Fernall (Defra). i Authors’ Organisations are as follows: Beaton, J.K., Brooker, R.W., Hester, A.J., Iason, G.R., Littlewood, N.A., Mitchell, R.J., Pakeman, R., Pozsgai, G., Ramsay, S., Riach, D., Stockan, J.A. and Taylor, A.F.S. The James Hutton Institute, Craigiebuckler, Aberdeen, AB14 8QH. Bellamy, P.E. RSPB Centre for Conservation Science. The Royal Society for the Protection of Birds, The Lodge, Sandy, Bedfordshire, SG19 2DL Broome, A. Forest Research, Northern Research Station, Roslin, Midlothian, EH25 9SY. Ellis, C.J. Royal Botanic Garden Edinburgh, 20A Inverleith Row, Edinburgh, EH3 5LR. Harmer, R. Forest Research, Alice Holt Lodge, Farnham, Surrey, GU10 4LH. Hodgetts, N.G. Bryophyte Consultant, Cuillin Views, 15 Earlish, Portree, Isle of Skye, IV51 9XL. Ray, D. Forest Research, Head of Land Use and Ecosystem Services Programme Group Centre for Ecology, Society and Biosecurity. Woodward, S. University of Aberdeen, Institute of Biological and Environmental Sciences, Department of Plant and Soil Sciences, Cruickshank Building, St. Machar Drive, Aberdeen, AB24 3UU. ii Summary1 Introduction 1. Hymenoscyphus pseudoalbidus (anamorph Chalara fraxinea) is an invasive fungus from East Asia that is currently causing the death or dieback of Fraxinus excelsior trees throughout Europe. For simplicity the disease is called ‘ash dieback’ throughout this report although other diseases can also cause the dieback or death of F. excelsior. F. excelsior is called ash throughout. 2. Previous work (Mitchell et al 2014, referred to as ‘Phase 1’ throughout this report) has already identified some potential ecological impacts of ash dieback on UK woodlands and on ash-associated species; has assessed the suitability of 22 alternative tree species to support ash-associated species; and has looked at the impact of various management scenarios on ash-associated biodiversity. This report is an extension of that work. 3. The objectives of this project are to: a. examine the ecological function of 11 tree species considered most likely to replace ash across the UK, b. assess the use ash-associated species make of a further 28 alternative tree species, c. undertake a ‘traits analysis’ of these 28 tree species to see how similar they are to ash, d. develop further management scenarios and assess the implication of these scenarios on ash-associated species, e. develop 15 case studies showing how existing management plans may be adapted to conserve ash-associated biodiversity should significant ash dieback occur at these sites, and to f. develop an Excel database containing information on ash-associated species and which alternative trees and shrubs support them. Methods to assess alternative trees to ash 4. One way of adapting to the potential loss of ash is to encourage the establishment of other tree species to replace ash. Such tree species are termed alternative trees throughout. From an nature conservation viewpoint the most suitable alternative