Chalara: Ash Die-back Virtual Woodland Environment
Introduction
Chalara dieback of ash is a disease of ash trees caused by the fungus Chalara fraxinea. The disease causes leaf loss and crown dieback, usually leading to tree death. First found in the UK February 2012, local spread is by wind and by movement of diseased plants over longer distances.
Woodlands in Scotland are infected, the distribution of sites of which is reported by the Forestry Commission, and can be viewed on the interactive map here. Background information on the disease, its origins, symptoms and precautions to reduce risks of spread are available from the Forestry Commission here.
A 3D model of a hypothetical ash (Fraxinus excelsior) woodland was developed to represent the symptoms and spread of Chalara ash dieback (Chalara fraxinea). The woodland was designed with characteristics of the vegetation and topography of a site in north-west Scotland. A model of different stages of infection was prepared and represented in a virtual environment.
Take the video walk-through the virtual reality model of the woodland and learn about the symptoms of the disease, and view scenarios of the loss of ash trees and regeneration of woodland trees. The virtual reality model can be downloaded from the Zenodo repository for use on a PC or with a virtual reality headset (e.g. Oculus Rift).
Download the virtual reality model and explore the woodland yourself. The model can be used with a virtual reality headset on a desktop computer. Instructions for the installation and use of the model are provided here.
Images of the woodland, scenarios of disease, and some surprising features you might find in the woodland are shown below.
Signs indicating an infected woodland
The Forestry Commission has designed signs which informing you if the woodland is infected by Ash Dieback, and what to do if you identify symptoms of the disease. Images of the two types of sign are shown below.
- Blue sign: woodland not infected; contact details provided if symptoms of the disease are seen in the woodland.
- Red sign: woodland infected; guidance on how to access the woodland responsibly.
View of an ash tree and symptoms of ash-dieback
Key symptoms of ash dieback are:
- blackening and wilting of leaves and shoots in the period from July to September
- infected leaves will be shed.
- infection can spread from leaves to twigs, branches and the trunk
- dark lesions (known as ‘cankers’) may be visible in the bark
- typically they are shaped as an elongated-diamond shape where branches join the trunk
- lesions often extend up- and downwards and eventually encircle the trunk
- as the tree grows the lesions dry out and open.
More information is available on the Forest Research WWW page Ash dieback (Hymenoscyphus fraxineus)
Effects of ash dieback disease as it progressively infects a woodland
Ash is a very significant tree species, supporting 955 species of flora and fauna. Of those 45 species only use ash trees and 62 rarely use other tree species. So, 107 species are most at risk from a decline in ash trees.
Ash casts light shade meaning many species can grow underneath it. If ash trees are replaced by tree species with darker shades then some ground flora species may decline
More detailed information about ash tree species, ash dieback, and tools to aid conservation of biodiversity associated with ash trees can be read on the James Hutton institute ecology Ash Dieback, and collaborating teams at Forest Research.
Views of progressive infection of a woodland by ash dieback disease
What else can you find in the woodland?
The woodland is also home to animals. Some of those are shown below. Can you find them when navigating through the virtual reality model?
How many animals can you find in the woodland?
Key message:
Before entering a woodland for a walk or cycle, and before leaving for home, clean your
Background to the development of the model is reported in the paper presented at GISRUK 2015, University of Leeds on Visualisation of spread of Chalara ash dieback for raising public awareness and responsible woodland access.
Acknowledgements: Thanks to the participants in the Moving Forward from Ash Dieback events at RBGE and Satrosphere. This work for the Chalara Action Plan was part funded by the Scottish Government as part of the Strategic Research Programme on Environment-Land Use and Rural Stewardship (2011-2016), Optimizing Land Use (WP3.5.5), the Ecosystem Services Theme (WP1.1.5), and the RBGE.
