DOCSLIB.ORG

Achieving Effective Rhododendron Control by Investigating Novel Methods of Forest Vegetation Management

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Achieving Effective Rhododendron Control by Investigating Novel Methods of Forest Vegetation Management Achieving effective Rhododendron control by investigating novel methods of forest vegetation management By Edward Daly Submitted in accordance with the requirements for the degree in Doctor of Philosophy Waterford Institute of Technology School of Science 2014 Abstract In Ireland one of the most serious invasive alien species which poses a threat to local biodiversity, particularly to our native woodlands, is Rhododendron ponticum L.. Rhododendron was first introduced to Ireland during the 19th century as an ornamental garden plant and has since become an established invasive species throughout Ireland. Rhododendron has also, in recent decades, become a significant management issue in plantation forests throughout Ireland. This study sets out to improve our understanding of the auto-ecology and invasion dynamics of rhododendron in Irish forests and to investigate control options to inform future rhododendron management plans. The study was divided into three broad areas. The first study sought to investigate the efficacy of a recently discovered Irish isolate of the fungal pathogen Chondrostereum purpureum as an inhibitor of rhododendron and Betula pendula (birch) sprouting in Ireland. The treated stumps were monitored for fungal colonisation and adventitious sprouting for the ensuing 18 months. The results demonstrated that a combination of mechanical cutting and the subsequent application of C. purpureum is not an effective method of vegetation management for either rhododendron or birch. As a successful primary invader, rhododendron is often found in areas when recent land management activities have taken place. Disturbed substrate coverage and the absence of predators provide rhododendron with optimum regeneration conditions. Many land management practices (particularly in a forestry situation) expose soil. To assess how the disturbance of vegetation relates to successful rhododendron establishment the degree to which the depth of substrate affects the germination of rhododendron seeds was tested. This second study 2 demonstrated that even small decreases in forest litter depth, sufficient to expose bare substrate, facilitates rhododendron seedling establishment. The third study set out to investigate whether the prevention of grazing of native scrub species in woodland sites could be used to prevent the spread of rhododendron. The findings to date suggest that fencing does increase the survival of native scrub species birch and Ilex aquifolium (holly). Also of note, in some of the plots, the holly and holly/ birch mix have successfully suppressed the re-growth of rhododendron. In conclusion, rhododendron has become a huge problem in plantation forest habitats and in order to control it effectively and economically an integrated pest management strategy will have to be employed utilising a mixture of novel bio-controls, innovative management strategies exploiting weaknesses such as seed longevity, viability and litter depth, and ensuring that other plant species can compete free of grazing pressures. 3 Acknowledgements I am very grateful to my supervisor Dr. Nick McCarthy, whose help and guidance has been invaluable through these years. Also special thanks to Dr. Sandra Irwin and Prof. John O’Halloran for their suggestions, corrections and ideas for all the manuscripts in this thesis. I would like to thank the Head of the Science department at Waterford Institute of Technology Peter McLoughlin for providing the working facilities within the department. Also special thanks to Dr. Milo Ó Rathaille for his invaluable help with the statistical analysis. I would like to thank Dr. Marion K. Seier, senior plant pathologist at the Commonwealth Agricultural Bureaux International (CABI) in the UK, who helped locate and isolate the Irish strain of C. purpureum. I am grateful to Dr. Aoife Dillon (Coillte) and the Lismore forest estate manager Mr Adrian Booth, both of whom provide the field sites for these experiments along with help and advice on establishing them. An Advisory Group was established as part of the PLANFORBIO research programme and met three times during this project. I am grateful to Dr. Daniel Kelly, Ms Sue Iremonger, Dr. John Cross, Mr Noel Foley, Mr Keith Kirby, Mr Alistair Pfeifer, Mr Tor-Bjorn Larsson and Mr Allan Watt for their advice and support on this project. Finally I wish to thank my family and friends; without their support this chapter in my life would not have been possible. 4 Table of Contents Abstract....... ................................................................................................................................................................2 Acknowledgements ................................................................................................................................................4 Table of Contents ....................................................................................................................................................5 Table of Plates ..........................................................................................................................................................8 Table of Figures .......................................................................................................................................................8 Table of Tables .........................................................................................................................................................9 1. Introduction ....................................................................................................................................................... 10 1.1 Invasive Alien Species ................................................................................................................................. 10 1.2 Rhododendron ................................................................................................................................................ 11 1.3 Rhododendron as an environmental threat. .................................................................................... 13 1.4 Rhododendron control................................................................................................................................ 16 1.5 Bio-herbicide control ................................................................................................................................... 17 1.5.1 Chondrostereum purpureum .......................................................................................................... 20 1.6 Rhododendron seed germination .......................................................................................................... 23 1.7 Herbivore grazing.......................................................................................................................................... 25 1.7.1 Browsing animals .................................................................................................................................. 26 1.8 Research Objectives ..................................................................................................................................... 28 Chapter 2: Assessment of the bio-control potential of the native fungal pathogen Chondrostereum purpureum as a cut-stump treatment to prevent re- sprouting of Birch and Rhododendron .............................................................................. 29 2.1 Background ...................................................................................................................................................... 29 2.2 Methodology .................................................................................................................................................... 31 2.2.1 Location and isolation of an Irish isolate of C. purpureum ............................................... 31 5 2.2.2 In vitro comparative growth rate experiment ........................................................................ 33 2.2.3 Birch methodology ............................................................................................................................... 34 2.2.4 Rhododendron methodology. ......................................................................................................... 38 2.2.5 Destructive Sampling .......................................................................................................................... 43 2.3 Results ................................................................................................................................................................. 44 2.3.1 In vitro comparative growth rate experiment ........................................................................ 44 2.3.2 Birch results ............................................................................................................................................. 46 2.3.3 Rhododendron results ........................................................................................................................ 50 2.4 Discussion ......................................................................................................................................................... 56 2.4.1 In vitro comparative growth rate experiment ........................................................................ 56 2.4.2 Birch discussion ....................................................................................................................................
Load more

Recommended publications
  • Tests with Wood-Decay Fungi to Control Sprouting from Cut Stumps Infected by Dutch Elm Disease
    $ 0HQNLVHWDO%DOWLF)RUHVWU\YRO ,661 Tests with Wood-Decay Fungi to Control Sprouting from Cut Stumps Infected by Dutch Elm Disease 1* 1 2 3 AUDRIUS MENKIS ,RIMVYDAS 9ASAITIS ,INGA-LENA ÖSTBRANT ,ALFAS PLIŪRA ANDJAN 1 STENLID 1 Department of Forest Mycology and Plant Pathology, Uppsala BioCenter, Swedish University of Agricultural Sciences, P.O. Box 7026, SE-75007 Uppsala, Sweden 2 Swedish Forest Agency Gotland District, P.O. Box 1417, SE-62125 Visby, Sweden 3 Institute of Forestry, Lithuanian Research Centre for Agriculture and Forestry, Liepų str. 1, Gi- rionys, LT-53101 Kaunas district, Lithuania * Corresponding author: [email protected]; tel. +4618672729 Menkis, A., Vasaitis, R., Östbrant, I.-L., Pliūra, A. and Stenlid, J. 2017. Tests with Wood-Decay Fungi to Control Sprouting from Cut Stumps Infected by Dutch Elm Disease. Baltic Forestry 23(1): 270-273. Abstract The Dutch elm disease pathogen Ophiostoma novo-ulmi in year 2005 invaded the Swedish island of Gotland, which pos- sesses large and valuable population of elms. The control of the disease is accomplished when infected elms are harvested and destroyed, and stumps are treated with the glyphosate herbicide to kill the stumps and the root systems, and prevent further spread of the disease to the neighbouring trees via root contacts. The aim of the present study was to test an alternative method to control the stump sprouting by deploying two species of saprotrophic wood-decay fungi as biological control agents. The study was carried out during three consecutive years 2014, 2015 and 2016. Fungal inoculum of Chondrostereum purpureum and Stereum hirsutum was prepared by cultivating vegetative mycelia in liquid nutrient medium and then formulating into a gel.
    [Show full text]
  • MEMOIRE DE FIN D'etudes Evaluation De L'activité Antagoniste
    REPUBLIQUE ALGERIENNE DEMOCRATIQUE ET POPULAIRE MINISTERE DE L’ENSEIGNEMENT SUPERIEUR ET DE LA RECHERCHE SCIENTIFIQUE UNIVERSITE BLIDA 1 FACULTE DES SCIENCES DE LA NATURE ET DE LA VIE DEPARTEMENT DES BIOTECHNOLOGIES MEMOIRE DE FIN D’ETUDES En vue de l’obtention du diplôme de Master 2 Option : Biologie des Interactions Plantes-Microorganismes Présenté par : BOUKERCHAOUI Saliha Evaluation de l’activité antagoniste des filtrats de cultures d’un isolat de Trichoderma sp. Vis- à-vis de quelques champignons phytopathogénes Soutenu devant le jury : BENCHABANE M. Professeur U. Blida 1 Président AMMAD F. M.C.B. U. Blida 1 Promotrice BOUCHENAK F. M.C.B. U. Blida 1 Examinatrice YALA A. Doctorante U. Blida 1 Invitée ANNEE UNIVERSITAIRE 2016/2017 Remerciements Ce travail a été réalisé au niveau du laboratoire de mycologie du département des Biotechnologies de l’Université de Blida1. Et au laboratoire de mycologie à l’institut national de la protection des végétaux d’El Harrach (INPV). Je remercie, en premier lieu, ALLAH le tout puissant de m’avoir donné le courage, la force et la volonté pour bien mener ce travail. Au terme de ce travail, Je tiens à exprimer toute ma gratitude, ma reconnaissance et mes sincères remerciements à ma promotrice Mme Ammad F. d’avoir accepté de m’encadrer, diriger et donné la chance de travailler ce sujet, sa confiance, sa disponibilité et la générosité qu’elle a m’ont accordée pour faire avancer ce travail. Je remercie sincèrement Pr. BENCHABANE M de m’avoir honoré en acceptant de présider le jury de mon travail. Je remercie également à Mlle BOUCHENAK f.
    [Show full text]
  • THE SILVICULTURE of TREES USED in BRITISH FORESTRY, 2ND EDITION This Page Intentionally Left Blank the Silviculture of Trees Used in British Forestry, 2Nd Edition
    THE SILVICULTURE OF TREES USED IN BRITISH FORESTRY, 2ND EDITION This page intentionally left blank The Silviculture of Trees Used in British Forestry, 2nd Edition Peter Savill Former Reader in Silviculture University of Oxford With illustrations by Rosemary Wise CABI is a trading name of CAB International CABI CABI Nosworthy Way 38 Chauncey Street Wallingford Suite 1002 Oxfordshire OX10 8DE Boston, MA 02111 UK USA Tel: +44 (0)1491 832111 Tel: +1 800 552 3083 (toll free) Fax: +44 (0)1491 833508 Tel: +1 (0)617 395 4051 E-mail: [email protected] E-mail: [email protected] Website: www.cabi.org © Peter Savill 2013. All rights reserved. No part of this publication may be reproduced in any form or by any means, electronically, mechanically, by photocopying, recording or otherwise, without the prior permission of the copyright owners. A catalogue record for this book is available from the British Library, London, UK. Library of Congress Cataloging-in-Publication Data Savill, Peter S. The silviculture of trees used in British forestry / Peter Savill. -- 2nd ed. p. cm. Includes bibliographical references and index. ISBN 978-1-78064-026-6 (alk. paper) 1. Forests and forestry--Great Britain. 2. Trees--Great Britain. I. Title. SD391.S285 2013 634.90941--dc23 2012043421 ISBN-13: 978 1 78064 026 6 Commissioning editor: Vicki Bonham Editorial assistants: Emma McCann and Alexandra Lainsbury Production editor: Lauren Povey Typeset by SPi, Pondicherry, India. Printed and bound in the UK by the MPG Books Group. Contents Acknowledgements viii Introduction 1 ABIES
    [Show full text]
  • Chondrostereum Purpureum As a Biological Control Agent
    Jan Lemola The efficacy of Chondrostereum purpureum as a biological control agent A comparative analysis of the decay fungus (Chondrostereum purpureum), a chemical herbicide and mechanical cutting to con- trol sprouting of broad-leaved tree species. Helsinki Metropolia University of Applied Sciences Bachelor of Engineering Environmental Engineering Thesis 7. 11. 2014 Abstract Jan Lemola Author(s) The efficacy of Chondrostereum purpureum as a biological con- Title trol agent Number of Pages 33 pages + 3 appendices Date 7 November 2014 Degree Bachelor of Engineering Degree Programme Environmental Engineering Specialisation option Renewable Energy Instructor(s) Leena Hamberg, Researcher (Metla) Carola Fortelius, Lecturer (Metropolia) In forestry, manual control of broad-leaved trees is tedious and costly. To reduce costs, chemicals have been applied to keep these species in control. However, some chemicals are not recommended to use because of possibly adverse effects on the environment. Instead of chemicals, biological alternatives, such as a fungus, Chondrostereum purpureum, might be used to prevent sprouting. C. purpureum is a common decay fungus in Finland; it has been investigated at Metla, to find out whether it could be used as a bio- logical control agent against sprouting of broad-leaved tree species. This thesis project is related to the Metla research project. The aim of the thesis project is to investigate, how efficiently C. purpureum prevents sprouting of broad-leaved tree species such as birch, aspen, rowan and willow when compared to chemical treatment and mechanical cutting only, and whether C. purpureum is able to penetrate into the roots of these broad-leaved trees. In the field, freshly cut weed trees were inoculated with C.
    [Show full text]
  • Silver Leaf Janet Van Zoeren, UW-Madison Entomology, and Patricia Mcmanus, UW-Madison Plant Pathology
    D0101 Provided to you by: Silver Leaf Janet van Zoeren, UW-Madison Entomology, and Patricia McManus, UW-Madison Plant Pathology Silver leaf is a fungal disease that affects a wide range of deciduous trees. What is silver leaf? The disease has its biggest impact in fruit trees such as apple, pear and cherry, but can also affect ornamental trees such as willow, poplar, maple, oak, and elm. Silver leaf has traditionally been considered a disease of older trees that have been physically damaged or are in decline due to other diseases. However, beginning in 2017, severe cases of silver leaf have been observed on young, healthy apple trees in commercial orchards in Wisconsin. What does silver leaf look like? The first symptom of silver leaf is a silver sheen that appears on leaves of affected trees. The number of leaves affected can vary dramatically from tree to tree. The silver sheen develops when the epidermis of a leaf (i.e., the surface layer of cells) separates from the rest of the leaf, altering the way that the leaf reflects light. The silvery leaves may also have brown, dead patches. Leaf symptoms may appear one year, but may be less severe or even nonexistent in subsequent years. Young, vigorous high-density apple trees, with trees showing Note that other tree stresses symptoms of silver leaf (on the right) adjacent to those that do (particularly environmental not (on the left). stresses) can cause leaf symptoms similar to those of silver leaf. An additional symptom that can help in identifying silver leaf is dark staining just under the bark of branches with symptomatic leaves.
    [Show full text]
  • Mistletoes of North American Conifers
    United States Department of Agriculture Mistletoes of North Forest Service Rocky Mountain Research Station American Conifers General Technical Report RMRS-GTR-98 September 2002 Canadian Forest Service Department of Natural Resources Canada Sanidad Forestal SEMARNAT Mexico Abstract _________________________________________________________ Geils, Brian W.; Cibrián Tovar, Jose; Moody, Benjamin, tech. coords. 2002. Mistletoes of North American Conifers. Gen. Tech. Rep. RMRS–GTR–98. Ogden, UT: U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station. 123 p. Mistletoes of the families Loranthaceae and Viscaceae are the most important vascular plant parasites of conifers in Canada, the United States, and Mexico. Species of the genera Psittacanthus, Phoradendron, and Arceuthobium cause the greatest economic and ecological impacts. These shrubby, aerial parasites produce either showy or cryptic flowers; they are dispersed by birds or explosive fruits. Mistletoes are obligate parasites, dependent on their host for water, nutrients, and some or most of their carbohydrates. Pathogenic effects on the host include deformation of the infected stem, growth loss, increased susceptibility to other disease agents or insects, and reduced longevity. The presence of mistletoe plants, and the brooms and tree mortality caused by them, have significant ecological and economic effects in heavily infested forest stands and recreation areas. These effects may be either beneficial or detrimental depending on management objectives. Assessment concepts and procedures are available. Biological, chemical, and cultural control methods exist and are being developed to better manage mistletoe populations for resource protection and production. Keywords: leafy mistletoe, true mistletoe, dwarf mistletoe, forest pathology, life history, silviculture, forest management Technical Coordinators_______________________________ Brian W. Geils is a Research Plant Pathologist with the Rocky Mountain Research Station in Flagstaff, AZ.
    [Show full text]
  • 02 Ramsfield
    Reprint No. 2867 Ramsfield — Chondrostereum purpureum in New Zealand 11 RISK ASSESSMENT OF INUNDATIVE BIOLOGICAL CONTROL WITH CHONDROSTEREUM PURPUREUM IN NEW ZEALAND T. D. RAMSFIELD Ensis, Private Bag 3020, Rotorua, New Zealand [email protected] (Received for publication 14 July 2005; revision 7 April 2006) ABSTRACT The host range and geographic distribution of the basidiomycete fungus Chondrostereum purpureum (Pers.) Pouzar in New Zealand were determined through analysis of herbarium records from Landcare Research and the New Zealand Forest Research Institute Limited, as well as published reports. The fungus has been recorded in every geographic region of the North Island, with the exception of Northland and Rangitikei, and from the northern portion of the South Island, as well as Southland, Otago Lakes, south Canterbury, and mid Canterbury, but it is known to be present throughout New Zealand. It has been recorded on 23 angiosperm families and 1 gymnosperm family in New Zealand. Based on the geographic distribution and epidemiological studies of the pathogen that have been conducted elsewhere, it is concluded that the utilisation of C. purpureum as an inundative biological control agent would not significantly alter the risk of infection by C. purpureum within New Zealand. Keywords: mycoherbicides; inundative biological control; Chondrostereum purpureum. INTRODUCTION Chondrostereum purpureum is a wound-invasive basidiomycete fungus that is currently being developed as an inundative biological control agent for woody weed control in Canada (Becker et al. 1999, 2005; Harper et al. 1999; Pitt et al. 1999) and The Netherlands (de Jong 2000) as an alternative to chemical herbicides. This fungus is also the causal agent of silver leaf disease of stone and pip fruits (Butler & Jones 1949) and extensive work has been conducted on silver leaf disease in New Zealand (i.e., Bus et al.
    [Show full text]
  • Application of Biological Control to Vegetation Management in Forestry
    Proceedings of the X International Symposium on Biological Control of Weeds 87 4-14 July 1999, Montana State University, Bozeman, Montana USA Neal R. Spencer [ed.]. pp. 87-96 (2000) Application of Biological Control to Vegetation Management in Forestry SIMON F. SHAMOUN Natural Resources Canada Canadian Forest Service, Pacific Forestry Centre 506 West Burnside Road, Victoria BC V8Z 1M5 Canada Abstract It has been well documented that some plant pathogenic fungi can be developed as inundative biological control agents (mycoherbicides) to suppress native competing for- est vegetation in conifer regeneration sites. Biological control agents need to be suffi- ciently virulent to mitigate the aggressiveness of competing vegetation, while allowing crop trees to compete successfully to the free-to-grow stage. To manage hardwood weeds in conifer regeneration sites and utility rights-of-way, an experiment was conducted to test the efficacy of the wound pathogen Chondrostereum purpureum (Pers.:Fr.) Pouzar as compared to the herbicide Vision®. Results indicate that C. purpureum is as effective as Vision® for control of red alder. In another pathosystem, weedy Rubus spp. are being tar- geted due to their capacity to rapidly invade reforestation and riparian sites, effectively reducing the growth and survival of young planted and naturally regenerating conifer seedlings. A potential candidate, Fusarium avenaceum (Fr.) Sacc. was selected and applied inundatively on target weeds under greenhouse conditions. Test plants receiving formulated F. avenaceum combined with 0.4% Silwet L-77 induced significant foliar necrosis. These two pathosystems are presented as examples for an applied biocontrol strategy for vegetation management in forestry and will be discussed in detail.
    [Show full text]
  • Chondrostereum Purpureum in the Sprout Control of Birch
    RESEARCH ARTICLE Breeding Increases the Efficacy of Chondrostereum purpureum in the Sprout Control of Birch Leena Hamberg*, Henna Vartiamäki, Jarkko Hantula Finnish Forest Research Institute, Vantaa Research Unit, Vantaa, Finland * [email protected] a11111 Abstract We tested whether the pairing of selected isolates could be used to increase the efficiency of a decay fungus Chondrostereum purpureum (Pers. Ex Fr.) Pouzar to control hardwood sprouting in Finland. We paired C. purpureum strains efficient in sprout control or highly ac- OPEN ACCESS tive in laccase production, and tested the efficacy of their progeny in spout control experi- Citation: Hamberg L, Vartiamäki H, Hantula J (2015) ments. This procedure resulted in a strain with an efficacy superior to that of the parental Breeding Increases the Efficacy of Chondrostereum strains. The mortality of birch (Betula pendula Roth. and B. pubescens Ehrh.) 1 cm in stump purpureum in the Sprout Control of Birch. PLoS ONE diameter was 78%, 56% and 9% for the best progeny, the best parental strain and the con- 10(2): e0117381. doi:10.1371/journal.pone.0117381 trol, respectively. Mortality was only slightly higher for B. pendula than for B. pubescens but Academic Editor: Petr Karlovsky, Georg-August- no significant differences were found between the number or maximum height of stump University Göttingen, GERMANY sprouts. Our results showed that cross breeding of this decay fungus is a good alternative in Received: October 3, 2014 attempts to produce efficient biocontrol agents against hardwood sprouting. Accepted: December 23, 2014 Published: February 12, 2015 Copyright: © 2015 Hamberg et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits Introduction unrestricted use, distribution, and reproduction in any In Finland, sprouting of broad-leaved trees is a hindrance in spruce (Picea abies [L.] H.
    [Show full text]
  • Susceptibility of Silver Birch Pruning Wounds to Infection by White-Rot Fungus (Chondrostereum Purpureum), a Potential Bioherbicide
    Silva Fennica 43(4) research articles SILVA FENNICA www.metla.fi/silvafennica · ISSN 0037-5330 The Finnish Society of Forest Science · The Finnish Forest Research Institute Susceptibility of Silver Birch Pruning Wounds to Infection by White-Rot Fungus (Chondrostereum purpureum), a Potential Bioherbicide Henna Vartiamäki, Jarkko Hantula and Antti Uotila Vartiamäki, H., Hantula, J. & Uotila, A. 2009. Susceptibility of silver birch pruning wounds to infection by white-rot fungus (Chondrostereum purpureum), a potential bioherbicide. Silva Fennica 43(4): 537–547. We artificially inoculated pruning wounds of silver birch (Betula pendula Roth) to study sea- sonal variation in their vulnerability to infection by the fungal decomposer Chondrostereum purpureum (Pers. ex Fr.) Pouzar. This information is critical to the assessment of incidental infection risks in areas where C. purpureum may be used as a bioherbicide. On seven monthly occasions between April and October 2005, 30 birch trees were pruned to yield a total of 210 experimental trees. On each occasion, 10 trees were inoculated immediately with C. purpureum mycelium, 10 were inoculated with blank inoculum and 10 were only pruned. In the summer of 2007, a survey of 129 experimental trees showed that pruning wounds were most susceptible to infection during May. Treatment with C. purpureum at other times during the growing season also increased the extent of discoloration or decay but the effect was considerably less. Keywords biological control, vegetation management, fungal decay, pruning,
    [Show full text]
  • Modelling the Escape of Chondrostereum Purpureum Spores from a Larch Forest with Biological Control of Prun Us Serotina
    .J Neth. J. Pl. Path. 97 (1991) 55-61 Modelling the escape of Chondrostereum purpureum spores from a larch forest with biological control of Prun us serotina 1 2 3 MEINDERT D. DE JONG , PATRICIA S. WAGENMAKERS and J. GOUDRIAAN 1 Centre for Agrobiological Research (CABO), P.O. Box 14, 6700AA Wageningen, the Nether­ lands; present address: Tarthorst 195, 6708 HJ Wageningen, the Netherlands 2 Research Station for Frui 1 Growing, Brugstraat 51, 4475 AN Wilhelminadorp, the Nether­ lands 3 Theoretical Production Ecology, Agricultural University, P .0. Box 14,6700 AA Wageningen, the Netherlands Accepted 25 October 1990 Abstract Chondrostereum pwpureum is being developed as a microbial herbicide to control Prunus serafina in coniferous forests. After biological control, the fungus produces basidiospores that may reach and infect non-target plants. As part of a risk analysis, spore escape from a forest was quantified. For this purpose, a stratified model was developed for a forest of 250m with 250 m. A turbulent diffusion equation was used to describe spore fluxes for each layer. In a simple calculation procedure, the spore fluxes for the different layers were calculated simultaneously. The downwind escape fraction was found to vary from 0.19 to 0.45, and the up­ ward escaple fraction from 0.07 to 0.23. These escape fractions increased with increasing wind speed. Number of spores released from basidiocarps, and escape fractions could be used as inputs for a Gaussian plume model to calculate spore immission into orchards. Additional keywords: simulation, spore dispersal, turbulent diffusion model. Introduction Chondrostereum purpureum is potentially useful as a biological control agent of Prunusserotina (black cherry).
    [Show full text]
  • Forestry Commission Field Book: Diseases and Disorders of Forest Trees
    Forestry Commission ARCHIVE DISEASES AND DISORDERS OF FOREST TREES A GUIDE TO IDENTIFYING CAUSES OF ILL-HEALTH IN WOODS AND PLANTATIONS by S C Gregory and D B Redfern Forestry Commission London: The Stationery Office © Crown copyright 1998 Crown copyright material reproduced under licence from the Controller of Her Majesty's Stationery Office and the Forestry Commission. Applications for reproduction should be made in writing to Crown Copyright Unit, Her Majesty's Stationery Office, St Clements House, 2-16 Colgate, Norwich, NR3 1BQ. Front cover, top left: Peridermium pini on Scots pine; pustules on a branch canker (see Figure 42 in main text). Front cover, top centre: Ramichloridium pini on lodgepole pine (see Figure 45 in main text). Front cover, top right: Oak leaves with spots and blotches caused by Apiognomonia errabunda (see Figure 60 in main text). Front cover, bottom left: Scots pine plantation in which most of the trees are dead or dying as a result of Bruncborstia infection (see Figure 46 in main text). Front cover, bottom centre: Fruit bodies of Lachnellula willkommii (see Figure 52 in main text). Front cover, bottom right: Atmospheric pollution injury in Norway spruce (see Figure 5 in main text). Back cover, left: Killing of shoot tip and buds of Sitka spruce by autumn frost (see Figure 30 in main text). Back cover, centre: Beech bark disease; " tarry spots" caused by Nectria infection (see Figure 63 in main text). Back cover, right: Breakage of a larch stem caused by Phaeolus schweinitzii decay (see Figure 71 in main text). Introduction 1 P A R T I A GUIDE TO DIAGNOSING TREE PROBLEMS 5 1.
    [Show full text]