Phytophthora ramorum outbreak

This page informs all campus users about the recent developments relating to the outbreak of Phytophthora ramorum (commonly known as “Sudden Oak Death”) within the campus woodland.

Working with the Food & Environment Research Agency (FERA), the University has endeavoured to eliminate the infection, but further infected Rhododendron ponticum has been identified and FERA are working with the University in developing a Site Wide Management Plan for the eradication of the infection.

Due to the risk of a further spread of Phytophthora ramorum, FERA and the Forestry Commission (FC) have advised that the best course of action will be to remove all the Phytophthora host plants from the woodlands across the University Campus. This includes the removal of all Larch from Springpool Wood (although it is expected that the Statutory Plant Notice (SPN) will require that all Larch across the campus will require felling), along with the removal of all Rhododendron ponticum from all the woodlands areas. Rhododendron ponticum has been found in Springpool Wood, Barkers Wood, Church Plantation and Terrace Plantation.

In order to complete the Programme of Works safely and efficiently, affected areas will be closed off or have restricted access for the duration of these works. This will start with the closure of Springpool Wood. Please see the following map for further information on the restricted areas.

Following the completion of the felling and clearance works, the FC has confirmed that the woodland areas should be replanted immediately. The replanting will consist of predominantly native broad leaf species which are not susceptible to Phytophthora ramorum. The re-planting work will not only look at re-instating the quality of the woodland and its heritage, but also creating and sustaining opportunities for on campus research and student engagement in the on-going upkeep of the natural estate. It will be challenging, but we will endeavour to keep the woodlands open and fully operational during all replanting

Following this communication is a Frequently Asked Questions (FAQs) leaflet and a map which outlines the Programme of Works.

We thank you in advance for your understanding and tolerance over the coming months.

Phytophthora is a genus of pathogens whose members attack plants and shrubs as well as trees. Phytophthora ramorum, the one that concerns us,was first identified in the mid-1990s as the cause of widespread devastation of wild oak trees in California and Oregon, USA (which earned it the name 'Sudden Oak Death'.

In Europe, including the UK, Phytophthora ramorum was initially found mainly on container-grown Rhododendron, Viburnum and Camellia plants in nurseries. It was first detected in the UK in 2002, when emergency measures were introduced. The initial measures included destruction of infected plants, a ban on imports of susceptible material from affected areas of the USA, and notification of movements of susceptible nursery stock. Those measures are still in place.

Rhododendron species, particularly Rhododendron ponticum was found to be an important host for the organism and was thought to be the principal means for spread of disease, leading to the first findings in native trees.

Most recently, in August 2009, the pathogen was identified on Japanese larch trees at sites in Somerset, Devon and Cornwall. Since then it has been found extensively in larch plantations in the south-west, in Wales and in south-west Scotland, leading to the felling of large areas.

It is of major commercial concern.

Phyotophthora infection Leaves infected with P. ramorum show a characteristic browning or necrosis that spreads along the mid-rib of the leaf. It has an optimum temperature for growth of 20°C and a requirement for moisture; it is therefore well suited to a cool-temperate climate.

It produces sporangia on the leaves and shoots of a wide range of plants; these are known as sporulating hosts. These sporangia are mostly spread locally over short distances during rain. P. Ramorum can be found in soil up to a depth of 15cm and leaf litter and can be moved on the footwear of humans and possibly on the feet of other animals, and potentially by vehicles.

It is also found to contaminate and persist in watercourses at infected sites but it is not known whether this can lead to new infections of plants. Long-distance spread is primarily by movement of infected plant material, e.g. in trade.

Tree hosts only produce infective sporangia from infected foliage. Some tree species only develop bleeding cankers; these do not produce sporangia and so are not sources of infection for themselves or for other host species. These trees become infected as a result of being in the proximity of sporulating hosts. In GB, all of the trees that have developed bleeding cankers have been adjacent to, or very close to, infected rhododendron, particularly Rhododendron Ponticum.

Examination of bleeding cankers has shown that P. Ramorum can be found extending up to 25mm into the wood of some tree species and can survive there for at least 27 months. This appears to be a dead end for the pathogen but it may be possible for this to lead to further spread via movement of infected timber. Currently no wood has been harvested from known infected trees in GB.

On the 7 August 2013 the University was issued with a Statutory Plant Health Notice 13/00717/01 by the Forestry Commission (FC). The infection was in the Larch plantation on the southern boundary in Lower Springpool Woodland and required that the infected tree and all Larch within a 100m radius of it were felled and destroyed. The time line for completion was by 31 March 2014. The University was fully compliant with this notice and its required timelines.

It is now evident that the P. Ramorum has continued to spread despite our efforts to reduce and contain it. As such, from discussions with both FERA and the FC, it is advised that the best course of action would be to remove all the Phytophthora host plants from the woodlands across the University Campus. This would mean the removal of all Larch from Springpool Wood (although it is expected that all will require felling under the SPHN) and the removal of all Rhododendron ponticum from all the woodlands across the campus. Larch makes up for approximately 20% of the Springpool woodland although the larch plantations are predominantly to the very south of the woodland nearer the motorway. Rhododendron ponticum is found in Springpool Wood, Barkers Wood, Church Plantation and Terrace Plantation.

As there is a requirement to fell the Larch before the end of October 2014 work is required to start almost immediately to ensure that we fully comply with the FC notice. The following map details the affected areas of the campus which will have undergone the programme of works.

The FC has confirmed that the woodland areas should be replanted immediately after the larch and Rhododendron Ponticum have been felled/cleared. FERA had previously advised a 3 year dormant period however it is now advised that replanting takes place as soon as possible to prevent excessive overgrowth of weeds/brambles, this is of course on the premise that replanting is with species that are not susceptible to infection or spread of P. Ramorum. Further to this the University has confirmed that a robust Woodland Management Plan (WMP) will be developed at the same time as this programme is being carried out.

It is proposed that the new planting will consist of predominantly native broad leaf species which are not susceptible to P. Ramorum. The WMP and final planting specifications will be developed together by E&D and the Natural Estate Advisory Group. 

Further updates will be communicated out via:

  • Campus staff email
  • Announce email
  • Regular meetings of the Natural Estates Advisory Group
  • Campus / Village notice boards

Ralf Sneyd was one of the first landowners in the country to introduce Rhododendron ponticum. It is indeed a pretty shrub when it is in flower. Unfortunately it spreads rapidly and in doing so can completely choke out and eliminate any natural flora and thus is a major threat to biodiversity. Few insects feed on it so there is little to control it. On the plus side it provides shelter for roosting birds and also nest sites for some too but this is outweighed by the negative effect that it has on the woodland as a whole.

Removal of the Rhododendron ponticum (the species Rhododendrons will be left alone - unless they too succumb to the disease) should greatly improve the health of the wood. It will let light in to the woodland floor and encourage native flowers and shrubs to grow.

It will obviously affect the area around Keele Hall and especially the Terrace Woodlands but we will be able to see the original drive from the Hall as it would have been in Sneyd's day.

Yes, we will see some great changes but it will be better in the long term; especially as we will be able to control re-planting etc.

Further information on Phytophthora Ramorum can be accessed via the Forestry Commission website (www.forestry.gov.uk) or the FERA website (www.fera.co.uk).