Woodland Protection
Woodland Protection
on the Langdale Estate
Tree Felling on the Langdale Estate: Ramorum Disease on Larch
In October 2020 the Langdale Estate was served with a statutory notice from the Forestry Commission to fell 36 Larch trees and remove large areas of rhododendrons because of the presence of the disease phytophthora ramorum – with both species being as infected as the other. The areas of the estate that fall under this order can be seen in the map below.
As a consequence, when you return to the estate you will notice areas of scarring and landscapes that are significantly more open than before and while every effort is being made to maintain the privacy that the Rhododendron provided, it will take a number of years to reach the levels that you have become accustomed to. The removal process will start in November and it is hoped that this will be concluded by the growing season, with as much planting as possible being delivered at the same time.
As part of the estates existing biodiversity strategy, the opportunity is being taken to re-plant in the areas affected with five different species, Ilex aquifolium (Holly), Berberris darwinii (Darwin’s barberry), Berberiss superba (Barberry), Taxus Baccata (Yew) and Elaeagnus ebbingei (Oleaster) which will in time, enhance the areas and provide the coverage and privacy similar to that that of the rhododendrons. A mixture of 143 native trees will also be planted in woodland areas, consisting of Silver Birch, Scots Pine, Hazel, Rowan, Yew and Holly.
What is Phytophthora ramorum (“P.ramorum”)?
Phytophthora ramorum is a fungal-like plant disease that infects more than 150 trees and shrubs species and spreads through its spores. The spores spread themselves by air or water and can also be picked up by animals’ feet. Phytophthora is not dangerous to humans or animals. It causes the death of a wide range of trees and shrubs. The greatest impact so far has been on larch plantations, which were widely planted for the timber market and particularly susceptible, leading to thousands of hectares of felling around the UK. That’s why it’s sometimes referred to as Larch Disease.
The Phytophthora species are microscopic fungal-like organisms closely related to algae, the name literally means ’the plant-destroyer’ and they have been responsible for some of the worst plant disease epidemics in history, including potato blight which led to the disastrous Irish potato famine in the 1800s.
Trees and plants have no defence mechanism against the disease so it slowly spreads throughout the tree and will eventually kill it. Once a tree has it, there’s nothing that can be done to stop its progressions so acting to prevent the disease spreading in the first place is the most important action to take.
An example of the infected plants in Langdale
There is no cure for the disease available at the moment, and there are no effective chemical treatments. There are fungicides which can suppress the symptoms, but none that will kill the disease.
The aim of any control measures is to prevent or minimise further spread of the disease and the damage it causes. The best available scientific advice is to remove and kill the living plant tissue on which the organism depends for reproduction. This means that infected plants that are releasing spores, such as larch trees, must be felled or otherwise killed as quickly as possible after detection of the disease.
How does it spread?
- ramorum spores spread via wind-driven rain. When they land on a leaf, they grow into the tree by breaking down the cell walls in the leaf. This leads to the initial blackening symptoms. It then grows within the tree and blocks its water transport system leading to dieback and eventual death. While this process is happening, the pathogen will also be spreading onto other nearby trees and shrubs.
Where has Phytophthora ramorum been found in the UK?
Trees in the wetter parts of the UK are particularly susceptible because the pathogen requires water to spread and infect its host. Major outbreaks on larch have occurred in south-west Scotland, Wales, Northern Ireland, and Cornwall.
Phytophthora ramorum moves around within plant networks very easily because it can’t be easily detected and is therefore hard to stop any spread. As a result, it is now widespread worldwide.
How do we know that trees have been infected?
Forestry England work with the Forestry Commission Tree Health Team who undertake regular aerial plant health surveys and flights and once identified they work with the local Forestry England teams to collect samples and confirm the infection on the ground.
How did Phytophthora ramorum get here and what impact will it have?
Phytophthora ramorum was first discovered in the UK in 2002 on an imported Viburnum plant. It can spread naturally in wind-blown rain (up to 4 miles), but it is the plant trade that spread this disease across the globe.
Phytophthora ramorum disease is here to stay. Before its discovery there were approximately 154,000 hectares of larch planted in Great Britain, 5% of the total woodland area. Most of this has been lost and larch can no longer be used as a timber species. There is also a risk that this pathogen can become aggressive on other hosts; this would be devastating to the natural environment.
What happens when Phytophthora ramorum is discovered?
When the Forestry Commission identify P. ramorum in an area the landowner is issued with an official notice to fell all larch and remove any rhododendron. This slows the spread by taking away the pathogens hosts and preventing spores from spreading.
For Further Information go to:
https://www.forestryengland.uk/west-phytophthora-ramorum
https://www.forestryjournal.co.uk/news/18003847.ramorum-resurgence-larch/