Most of us are aware that trees capture and store carbon dioxide from the air, helping us to keep breathing and in the fight against climate change. What is possibly less well known is their ability to trap particulates and even other substances from the air around us. This principal has long been used in cities, with species such as London Plane (Platanus × acerifolia) being planted in avenues to help filter air pollution and keep lungs healthy as well as having a cooling effect in summer.
Farmers can also plant trees to mitigate the negative byproducts of intensive farming. Recent guidance from The Centre for Ecology and Hydrology (CEH), and Forest Research (FR) provides a calculator and information for farmers and land owners to ensure they utilise the properties of farm woodland planting for ammonia capture and sequestration. Woodland design and species choice plays an important part in how well the shelter will function as an air filter, and the guidance goes a long way to helping develop this.
The guidance and calculator can be found using the links below:
As part of routine surveillance, plant health officers from the Forestry Commmission have discovered a breeding population of Ips typographus (eight-toothed European spruce bark beetle) in an unnamed woodland in Kent: the first such finding in the wider environment in the UK.
Sawmills and commercial timber growers will be especially concerned, as large populations of these beetles can cause significant damage to softwood plantations; although they tend to attack already weakened or windblown trees as a preference. If populations reach a high enough level, they can cause stand level die back as large groups attack individuals or groups of trees and overwhelm their natural defences, as in the picture below.
Movement controls and quarantine procedures have been put in place, while further intensive investigations are carried out. A Contingency Plan that was already in place due to the high risk posed by Ips typographus has been implemented.
Here we see an excellent, if worrying, example of how the knock on effects of climate change could be wide ranging and indirect; the direct impact on human lives of the huge and deadly forest fires could perhaps not have been predicted from the seemingly insignificant increase in breeding potential of a tiny bark beetle.
The European spruce bark beetle creates distinctive breeding galleries such as the one in the title image – a central channel with radiating galleries of increasing size. If you think you have spotted some of these symptoms / insects, please let the FC know by using their Tree Alert Form.
This story will probably be buried by the ongoing Brexit coverage in the news, but a new report by the Climate Change Committee (CCC) has recommended a dramatic increase in tree planting targets if we are going to address global warming predictions:
This will be welcome additional pressure on the government for environmentalists and foresters, but with the recommendation that up to 30% of grazing land could be planted it is likely there will be some push back from farmers and food groups who are concerned we don’t currently produce enough of our own food in the UK; especially with uncertainty over our relationship with the EU, where the greatest proportion of our food imports come from.
The suggestion that farms could make up the reduction in production by “being more efficient” would likely be rejected by most farmers, but I think most would accept that the reduction and indeed elimination of food waste is essential, with 1.9 million tons currently going in the bin every year in the UK alone. Some that I have spoken to have seen it almost as an insult that they should be paid so little by the supermarkets for a product they have worked hard to grow, only for it to be thrown away. https://fareshare.org.uk/what-we-do/hunger-food-waste/
Perhaps there is an answer in the field of Agroforestry, where trees are planted alongside livestock and crops to improve their yield, give increased drought tolerance and shelter in extreme weather events and against dessicating wind. More on this in future posts.
– Above: Felling and snedding (or “bucking”) large Norway or Sitka spruce by hand.
The Newfoundland Forestry Battalion were formed from Newfoundland and Canadian volunteers, as a response to the growing timber shortage in WW1. The link below details a cracking story of how these men were shipped in to work huge areas of forestry in the harsh Scottish Highlands, almost entirely by hand and with little to no logistical support. The article even says part of their terms when joining up were to provide their own tools; they had to build their own accommodation using the timber they had felled and construct log flumes (the like of which had not been seen in Scotland to that point) in order to access the harsh and difficult terrain where the timber had been planted. Different times.
If you enjoy this website, you may be interested in heading over to http://forestry-memories.org.uk/ as well. This site contains a tree-mendous (I’m sorry) collection of archive material from people who have worked in the timber industry in Scotland over the last century or so. All of it has been catalogued, and much of it annotated, with the help of the owners and researchers from the University of the Highlands and Islands (UHI) and with funding from the EU.
I am in the process of starting a similar project for the rest of mainland England (and possibly Wales?), if anyone is interested or has material they may be willing to contribute / share, please feel free to get hold of me using the ‘Contact’ page.
This week, I’m on a course in the Scottish Highlands looking at growing broadleaves for quality timber, particularly in the upland context. The course has been developed and is run by Jens Haufe of Forest Research.
A large number of broadleaves have been planted in the UK over the last 20 years or so, in new woodlands and also replacing stands of conifer that have been felled for timber. Planting designs are usually chosen for amenity or wildlife value, and with very little thought given to the end use of the wood other than perhaps a bit of firewood. Estates that focused their time and efforts on growing quality oak, for example, have tended to be more in the fertile lowlands (Shropshire, Herefordshire, Oxfordshire) and on the continent, not in the British uplands, where markets are less developed, growth rates slower and there can be more issues with exposure and soil fertility. More and more often though, forest managers, owners and regulators are now thinking that we would like to see more planning going into these woods, so they can provide something of harvestable timber value for future generations.
To achieve this, we really have to go with one of two options. Option A – Plant or seed at high density, allow the trees to outcompete and drive each other upwards towards the light and then pick the best to be your ‘final crop trees’, or Option B – plant at a lower density, spending less money initially, but spend more time pruning and taking out undesired competition from the mixture.
We’ve seen some interesting examples of both today, from oak ‘nests’ which are planted in very tight spacing on a tiny area dotted across a site, the idea being that only the best tree from an individual nest will be kept as final crop tree:
To more conventional (at least in British context) planting designs, where trees were planted in tubes, and distributed evenly over the site:
This site will need to be managed in the near future to thin out the birch and ensure it does not over-top the desired oak crop.
The other major choice that we need to make when starting is what species to use in order to make best use of the ground and maximise potential timber value, while achieving any other objectives we may have in terms of wildlife or landscape. Some species are better suited to option A described above, others to option B. For example, oak is quite light demanding and needs competition to push it straight upwards, shading off side branches and maintaining timber quality at the same time, leading us to consider option A at establishment. Cherry is a good example of a tree that will naturally grow straight upwards (good apical dominance) but will not self prune, so does not gain any benefit from being planted at high density. Rather, trees should be well spaced and then manually pruned to encourage good timber quality, as will be required on the tree below.
Tomorrow we are going to be looking at the next stages of the trees’ life cycle, including thinning and respacing to ensure the best trees make the final cut.
Greetings, loyal readers; belated seasons wishes and all the best for this New Year.
2017 has come and gone, and brought with it more than its’ fair share of upsets and tribulations. I thought I would roll in to the new year with a few noteworthy and hopefully positive items from the world of wood over the last few weeks and months.
Two new large scale commercial woodlands were given the go ahead by the Forestry Commission in November; one on Lowther Estate, near Penrith, the other at Doddington North Moor near Wooler in Northumberland. The latter made the news for all the right reasons:
As the article states, Doddington is the largest new productive forest planting scheme to have been approved in the last 30 years. It is hoped that it will deliver long term benefits for the environment, by improving habitats and producing sustainable building materials, as well as generating and sustaining jobs in the local area while the forest is planted, fenced, maintained, thinned, and finally harvested and converted into timber or firewood.
Down in the Forest of Dean, my old patch, the local team have just been given the go ahead to proceed with a trial release of beavers to assess potential flood alleviation benefits arising from their damming activities. There has been increased interest in recent years in ‘natural flood management’ (NFM), replicating natural processes (usually in the upper reaches of a catchment) in order to reduce flooding risks further downstream. Beavers have been highlighted as a species with high potential for reducing flood risk and improving water quality through their natural dam building activities, slowing the flow and reducing sediment load. The study is intended to demonstrate and quantify these effects on a relatively small water course in the Forest of Dean which has previously been known to flood severely.
For a little while it looked like the scheme wasn’t going to be given the go ahead, having been put on hold indefinitely by DEFRA. However, it seems that the decision has been made that the ecological benefits from re-introduction and the beavers’ potential as a future natural flood alleviation measure outweigh any risk.
Just before Christmas Judi Dench presented a programme about the many wonders of trees in an artistically personalised / semi-scientific approach to demonstrating why these are organisms worthy of our time and attention.
Early in the New Year, on the 8th of Jan, is a new programme called The Forest, which will hopefully cover another of managing trees and woodland, from a more commercial perspective, and may give an interesting insight into how productive forests in the uplands are managed and the many factors taken into consideration. Some advance clips can be viewed below.
I’ve recently started a new job, back in the North East of England. Last week I was lucky enough to visit a nature reserve in Gosforth Park, Newcastle upon Tyne, which I had no prior knowledge of, despite having lived in the North East for some 20-odd years.
The site is managed by the Natural History Society of Northumbria, on a piece of land owned by and adjacent to Gosforth Race Course. The access to the reserve is unassuming, off an old lay-by next to the A189:
My initial impression was that of an ancient, semi-natural woodland, though I soon found out that the wood had been planted for less than one hundred years. As soon as you walk into the wood, you are struck by a sense of naturalness and wildness, although when you look closely, you can still see traces of mounds from plough furrows in the ground. In the middle of the manicured city, it is a refreshing change. The reserve is managed entirely with conservation objectives in mind, with the emphasis on enhancing habitats for birds and invertebrates.
A number of students from Newcastle University and other institutions have carried out studies on various aspects of the wood over the years. There are currently plans to modify drainage off the site, to allow it to store more water during flood events due to the run off from neighbouring housing developments. There is already some wetland on the site, and this transition will increase the amount of wet woodland present (alder, birch, willows) at the expense of some of the more dominant oaks and beech.
I realised I was looking at the wood to start with, very much from a Foresters’ viewpoint. We tend to see what resource is there, and what will be the best way to get at it (in a sustainable and environmentally sensitive way). However, in talking to the people responsible for managing it, who have done some good work in transforming some of the areas that were planted up with spruce back in the 1970’s, I reminded myself that not everywhere needs to be intensively managed for timber, especially in the middle of the city where such oases are rare. I do believe that we should make best use of the resources that we have, especially if they arise from management which is for the best of the wood or the habitat as a whole, but we also need wild places.