The nature of CAT – an interview with the woodland team

We are extremely proud of our biodiversity here at CAT and are very lucky to be surrounded by such rich habitats every day. We caught up with Alex Chadwick, a Conservation Development Assistant and part of the woodland team here at CAT, to learn a little bit more about how the site is managed for nature and to find out what wildlife to look out for at this time of year.

Continue reading “The nature of CAT – an interview with the woodland team”

Woodland volunteering placement opportunity

Woodland Volunteer
Woodland Volunteer
Woodland Volunteer Gareth

Six month volunteer placement

This is Gareth. He has just finished six months as volunteer in our woodland. He learned a lot about social forestry, green woodworking and woodland management. We have a position available for a new volunteer, starting in October. We would love you to join us to help manage our woodland through the winter season.

Gareth said:

‘volunteering in the woodland department was an incredibly rewarding experience… Hard physical work, but in beautiful surroundings, learning practical skills and developing creatively alongside knowledgeable and supportive folk’

We are also looking for volunteers in the media department and the gardens

Click here to find out more about our volunteer opportunities. Placement dates are flexible but ideally starting in October.

New Skills in 2014 – Hedgelaying and Restoration

We have a host of exciting new short courses taking place at CAT in the new year, so if you fancy learning something new in 2014 then what about the traditional art of hedgelaying? Our weekend course on Hedgelaying and Restoration will run between the 31st January and the 2nd of February 2014. Why is this skill so important?

The course involves both theoretical and practical learning onsite at CAT with Rob Goodsell. Students will learn about different types of hedges, the ecosystems found in them and the traditional tools used to create them. Rob is an experienced woodsman with a hands-on approach to learning. He is been a long-time member of the CAT staff, working in water resources and woodland management. His teachings emphasise the importance of sustaining vibrant landscapes by using sustainable methods and techniques.

Tutor Rob Goodsell

Nowadays, hedges are often ‘flailed’; the tops are cut off using large automated machinery. This technique is not very sustainable. Rob explains that “flailing breaks down the hedgerows and will not promote new growth of the plants and will negatively impact on species, such as bats, that use these corridors to navigate. Flailing looks neat but it is not good for the countryside.”

Most hedges in the UK have been maltreated for over 30 years, so bringing them back to life is vital. Learning how to construct hedges in a more traditional way promotes habitat corridors, while allowing the local flora and fauna to flourish.

Find out more about this course on our website. Until 31/01/2014 we are offering 10% off this short course. 


Biomass in Zero Carbon Britain: Breaking the Chain of Destruction?


Biofuelwatch, a campaign organisation against large-scale bioenergy (using biomass to produce energy) have launched a new report – Biomass: the Chain of Destruction – focusing on the human and environmental costs of biomass-focused UK renewable energy policy.

The report states that:

“Large ­scale electricity generation from biomass is a key element of the UK Government’s renewable energy policy. Their 2012 UK Bioenergy Strategy states that bioenergy could provide between 8 and 11% of the UK’s primary energy demand in 2020 […] Although bioenergy includes biofuels for transport, the bulk of it would come from burning wood.

Biomass electricity is supported by generous subsidies and energy companies have announced plans to burn […] more than eight times the UK’s [current] total annual wood production.”

In conjunction with their report released last year – Sustainable Biomass: A Modern Myth – the organisation highlight the pitfalls of trying to meet greenhouse gas emissions reductions targets by converting to baseload biomass electricity generation plants. That is, burning large quantities of biomass (usually wood pellets) around the clock to produce electricity, similar to how we currently generate electricity from coal.

Burning biomass instead of, for example, coal, is seen as ‘carbon-neutral’ because the carbon dioxide (CO2) released in its burning has been taken in already as the wood has grown – there are no net greenhouse gas emissions over the life cycle of the biomass. Coal, in comparison, emits greenhouse gases into the atmosphere, contributing to climate change.

CC. Andy Polaine, Flickr.


Most of the issues surrounding biomass use for energy derive from concerns about whether or not policies surrounding biomass growing and use will, or do work. For example, do they:

  1. Count all the carbon in the biomass life cycle properly, and take into account the ‘carbon-payback’ time. For example, if an older, carbon-rich forest is cut down and replaced by a short-rotation (comparatively carbon-poor) stock of biomass, then the energy produced using that biomass would not be carbon-neutral in absolute terms.

  2. Stop deforestation and the ruining of natural landscapes, communities and cultures in the process of growing biomass or establishing new plantations.

  3. Keep biomass usage to a sustainable and non-exploitative level. Is it right to use precious land (often not in the UK) to cater for our high energy demands, when it could be used for food production or supporting biodiversity? Catering for all UK electricity demand would require tens of millions of hectares of land for growing biomass according to the report (the area of the UK is about 24 million hectares in total, as a comparison).

Encompassing all of these things, key questions are: ‘is biomass sustainable?’, and ‘is it really carbon-neutral’? And even if it is both of these things, is it actually a good option for low carbon energy provision in the UK?

The argument goes that if policy does not work, then energy from biomass is no good from many different, not just climate-related, perspectives. This means biomass use hinges on good policy mechanisms, their strong implementation, and objective and impartial verification. Are we capable of this?

It would appear that currently we are not. The new report includes the first ever study of a land-grab in Brazil for eucalyptus plantations directly linked to UK demand for wood pellets, and documents the impacts of a UK power station’s pellet demand, sourced from the destruction of ancient forests in the southern US and Canada.

Biofuelwatch member Oliver Munnion said: “This is just the tip of the iceberg, and what we’re seeing is the impacts of a rapidly growing industry and the speculative investments of irresponsible companies, spurred on by generous subsidies and non-existent sustainability standards.”

However, whilst biomass is not, and cannot be the solution to all our energy needs, it is useful in some cases, though its use should be kept to a minimum, as a ‘last-resort’. Baseload biomass (for example replacing coal with biomass in large power stations) is not sensible when biomass resources are limited, can have detrimental impacts globally, and especially when we have so many other ways of generating electricity.

Biomass in ZCB

Throughout the Zero Carbon Britain project we ask, what resources do we have for energy provision in the UK? In other words, where are our strengths? We end up with a good mix of renewables in our scenario, but we are dependent on wind (both onshore and offshore) for about half of our energy on an annual basis because we are fortunate enough to be one of the windiest countries in the world. With relatively small per-capita land area, building up our capacity to produce electricity from wind resources, rather than biomass, makes much more sense.

Furthermore, Zero Carbon Britain hourly modelling of our electricity supply and demand shows that baseload power (i.e. burning biomass instead of coal, or nuclear power) does not help cater for shortfall in electricity demand in a system that has a high degree of renewables in it. When our supply and demand for electricity go up and down at different times, what we need is a flexible back-up energy supply, not one that runs constantly – we only need to fill the gaps, not produce more energy all of the time.

And this is where careful use of biomass comes in handy. In Zero Carbon Britain, there are some energy demands that can’t currently be met with electricity (the type of energy produced by renewables) – some transport and industrial demands. Furthermore, we need to be able to store some energy over long periods of time (weeks or months). Electricity isn’t very storable on the scale necessary to cater for even the much reduced UK energy demand in our scenario. Converting biomass and hydrogen into synthetic liquid and gaseous fuels helps with these issues. In Zero Carbon Britain, we keep biomass use to a minimum. We use hydrogen produced using excess electricity (when supply from renewables exceeds demand) in chemical processes to get more out of our biomass, so that we need less of it.

But how do we ensure the biomass we require is sustainable, and actually carbon neutral? In Zero Carbon Britain:

  • We grow all the biomass we require for energy in the UK. In total, we use about 4 million hectares of land to produce grasses, short rotation forest and coppice. We think that providing our own biomass for energy offers us the best chance of being able to be in control of good policy implementation surrounding its growing and use, and verification schemes that keep the production sustainable and carbon neutral.

  • We mostly grow this biomass on ex-grazing land meaning no old forests are cut down. In fact, at the same time we plant an additional 4 million hectares of forest, providing more wood products for the UK, and leaving more space for biodiverse woodlands. There are no knock on effects for the food industry either.

  • Changes in diet in the Zero Carbon Britain scenario mean we can do all this, and still provide a healthy, balanced diet for the UK that needs to import less food.

  • The impact the UK has on land overseas in our scenario would be less than it is today.

There can be (and are currently) many serious and dangerous issues with the growing and using of biomass for energy. However, with a sensible (and limited) approach to its use, strong policy backing, and independent verification, we can make sure the biomass we use is sustainable and carbon neutral.

One of the things Biofuelwatch calls for is “a major policy shift away from large ­scale energy generation through combustion, towards our energy needs being satisfied through a combination of genuinely climate ­friendly renewable energy and a substantial reduction in both energy generation and use.” And providing that there is still some room for use of truly sustainable and carbon-neutral biomass in appropriate places, then we’d agree.

Working in the Woods

CAT is currently recruiting for some lovely long-term volunteers to join us here in mid-Wales. Are you looking to gain experience in woodland management, horticulture or marketing? CAT has five or six-month placements in these areas and we are recruiting in a rolling basis. Over the next three days we’re going to take a closer look at the different roles. If you are interested in applying then check out our volunteering website.

First up:

Water and Natural Resources Volunteers

Using a draw knife to make a traditional Welsh gate.

We’re looking for two people to work in CAT’s Water and Natural Resources department. This is a brilliant opportunity to learn about traditional coppice skills, correct tool use and care, sustainable woodland management, biodiversity survey work, land and estate management, wetlands and eco-sanitation. CAT’s woodland website has loads of further information about each of these areas.

The people we’re looking for may not necessarily have experience in this area, but they will:

  • have a genuine interest in woodland and natural resources
  • have practical skills
  • be happy to get a bit grubby
  • be flexible with an enthusiastic and positive disposition
  • be keen to learn
  • willing to complete physical work outside in all weathers


Iñigo, a previous volunteer had this to say about his experience: “I like being involved in the woodland and working outside, being in contact with nature through the work that we are doing and trying to preserve biodiversity. I think it’s a great experience to have and to take some skills and to develop a different view of what you can do with them, and to improve sustainability and to be a change maker in some way.”

Visit the volunteering website for more information about this placement.

Creating a Pond at Coed Gwern

Jony Easterby, an Artist in Residence at CAT, has been working on creating a pond over at Coed Gwern – CAT’s mixed woodland. His blog, first posted here, charts the development of the pond up to early summer.

I thought I would start by up putting a quick sneak preview of the work I have been doing as part of my Leverhulme Fellowship artist in residence up at CAT. I have been working on and off between other projects to integrate my artistic practice into the Landscape of the Dyfi Biosphere, something I have been keen to do for many years, as my work usually takes me out of the valley, and indeed mostly out of Wales. It seems to be working as I have completed one project in South Wales and am nearing the completion of a landscape scale pond work up in the woods at Coed Gwern.

The site for the pond

Working with Grace Crabb in the CAT biology department, I soon discovered the CAT woodland project. Thirty acres of well-managed mixed woodland. We talked about what I have been doing and Grace talked about the need for an area of standing water to encourage a different range of habitats for amphibians and invertebrates. An area of predominately Birch and Douglas Fir was identified, and I began to mark out a ten meter diameter space. I also looked at the watershed and thought that I would enhance and make a feature of the drainage channels already existing in the woods.

After marking out, saws came out and I chopped down and transplanted a lot of saplings. I then hired a small excavator and started to dig. The ground is heavy waterlogged peat from years of moss and woodland on the site. Easy until its starts to rain. It then takes a lot of fiddling around and some tricksy techniques with the bucket to get the machine out.

I bought the machine onto the site three times at different stages to get the profile right,using a  rotary laser level to get the water level exactly where I needed it to be. The pond stayed like this all winter as I waited for a drain bung and for the levels to slump, this means I can drain it down if I need to work on any part of the drawdown zone or island.

Early spring saw the first frogs move into a large puddle of muddy water and drop off a pile of frog spawn…..our first inhabitants……Its working!

After a few months  I felt happy enough with the site to start planting an avenue of trees and re-establishing some of the vegetation, transplanting polypody ferns and working on the creation of moss habitats. I have used non-native  betula jacquemontii, a well used landscaping tree, which is long lived and very white. It is also sterile in this country so will not mess with the natives.
Eager CAT volunteers

Stella the dog was at hand to catch voles and help with the digging as you can see. Also at hand was Adam Thorogood who bought CAT volunteers over to help put steps in and build a boardwalk around the edge of the pond. This is being made of riven oak to give an organic feel. The timber has been sourced from the surrounding oak woodland by Jules Russell a local woodsman and craftsman, who has also been helping on the build.

Catching up with our water and natural resources volunteers

A report from our wonderful water and natural resources volunteers on the work they have been doing.

Managing the woodland:
Coed Gwern is 15 acre woodland managed in a sustainable way by CAT, ensuring and enhancing biodiversity. The spring season is a very important time because many of the migrant birds are coming back to our woodland and life increases after the long stopped of the winter season –bird nesting, trees blossom, etc-.

Throughout the spring we have been making bird boxes and cleaning coppice areas, a special work related with two different protected species: Willow tits and Dormice. A number of areas of the woodland have been prone to flooding and we have been managing this by building dams and ponds, to retain the rainfall. This should help the different bird species (migrants and residents) to nest and find food supply for their chicks and themselves.

The CAT woodland is a great home for willow tits

However, we don’t just build ponds and dams to slow water down or retain it. Recently we built a small pond in front of the bird hide at Coed Gwern so birds can drink out of it and even maybe bath.

Needless to say that these watery places will just be heaven for species who like getting wet. Pond skaters (these large mosquitoes look alike insects skating over the surface of the water) are usually the first ones to appear, then will come other invertebrates like dragonflies, spiders and frogs.

Monitoring changes: In January 2013 the Water and Natural resource department started an exciting new project involving the local community. The woodland is divided in 24 monitoring points which have been adopted by different people and groups. Through this project we are able to follow changes in the plant and animal life.
We have also been improving the network of paths and walks, placing signs to facilitate a good use of the woodland by visitors.To get involved in the woodland monitoring project contact:

Spring’s also the time to find out bird nesting sites. So  two monitoring routes were chosen and measured (100 meters long each) to survey bird species on a map once a week. This work, carried out over 5 weeks requires bird call and song listening skills as well as identifying birds. This work will enable us to draw up a map of the different nesting sites across Coed Gwern

Art in the woodlands: We have been involved in a biodiversity and arts project, developed by Jony Easterby, to build an artificial pond in the woodland. The pond is designed to be both a natural space for people to enjoy and promote water conservation.

Greenwood crafts: As one of the main activities in the winter and spring months is clearing, it makes perfect sense to use the cleared wood for building gates, fences and splitting logs for firewood next year.

The bird hide builders

Building Bird hides: In the last two months CAT volunteers have been working in a project to build a bird hide in the slate quarries, old dynamite hut. Wall stones were removed shifted, added, levelled and rubble was taken out of the ground to even it out. Once the walls were at the right height, the wood work came along (timber frame for the roof and planks above the walls and under the roof with openings to make it a proper bird hide). Last but not least it has got a proper metal roof, which provides good shelter for bird-watching and listening, rain and sun. So the bird hide is now up and roofed. We are now working on displays to help visitors identify woodland and field bird species, and benches to just sit and enjoy the different sounds of nature!

Worm research: We have continued with research that started last year into the use of tiger worms and compost toilets for developing countries

For more information on volunteering and working at CAT please check our webiste, we currently have a number of positions open for volunteers.

Glue Laminating at Grand Designs Live

This year CAT has been on bit of a promotional tour – travelling to London, Birmingham and London again to attend exhibitions, study fairs and conferences. Each event gave us the opportunity to talk to people about CAT’s work in the field of sustainability. From this coming Saturday however, CAT will be doing more than just talking.

We’re spending nine days camped out in the miniature village that is Grand Designs Live at the ExCel in London. Each day CAT will be providing demonstrations of glue laminating (or glulam) used to build the beautiful ‘wigloo’ you can see onsite in Wales. Jules, the carpenter who designed the toilet in association with Crafted Space, will be doing two demonstrations each day. As well as this, we have some examples of sustainable building techniques with us and the opportunity for people to ask CAT experts questions about their building woes.

Timber Arc Compost Toilet
The glue laminated compost toilet up at CAT

So what exactly is glue laminating?

It’s a process where several layers of timber are bonded together using a durable, moisture-resistant adhesive. The resulting structure can be used in both straight and curved configurations. The build that Jules undertaking requires curved lathes so he uses a ‘former’ to help hold the layers in place as the glue dries.


So why glue laminating?

Glue laminating has much lower embodied energy than reinforced concrete and steel, although of course it does entail more embodied energy than solid timber. However, the laminating process allows timber to be used for much longer spans, heavier loads, and complex shapes.

Glulam is two-thirds the weight of steel and one sixth the weight of concrete – the embodied energy to produce it is six times less than the same suitable strength of steel. Wood has a greater tensile strength relative to steel – two times on a strength-to-weight basis – and has a greater compressive resistance strength than concrete. The high strength and stiffness of laminated timbers enable glulam beams and arches to span large distances without intermediate columns, allowing more design flexibility than with traditional timber construction.

Glue Laminating
Jules clamping some glue laminated timber onto the former

We’ll be following the build live each day over on Facebook so have a look and see how it progresses!

If you like the look of the compost toilet, take a look at Jules’ website.

Grand Designs Live is open to the public from Saturday 4th to Sunday 12th May. More information can be found on their website.