Podcast: Turning disused quarries into nature reserves

Diagram showing examples of geoengineering

Paxton Pits Nature Reserve

6 August 2013 by Sue Nelson

This week in the Planet Earth podcast, Helen King of Cranfield University, Jim Stevenson of Paxton Pits Nature Reserve, Cas Jewell of Nature after Minerals, and David Payne from the Mineral Products Association explain how environmental science can be used to turn old quarries into brand new habitats.

To assist those who find text-based content more accessible than audio, a transcript of this recording is available below.

Sue Nelson: This time on the Planet Earth podcast, from the noise and the gravelly environment of a quarry to the wildlife haven of a nature reserve and the benefits of ecosystems services.

Hello, I'm Sue Nelson and I am at the Paxton Pits Quarry in Cambridgeshire. I'm with David Payne from the Mineral Products Association. What sort of quarrying goes on here? I mean we have the gravel beneath our feet and there are mounds of gravel and sand in front of us.

David Payne: Yes, it's an old sand and gravel quarry, so there are a lot of these quarries around in the South of England, taking sand and gravel from river valleys.

Sue Nelson: And what's the average life of a quarry like this because there are hundreds around the UK exactly like this.

David Payne: Generally around 20 years but they do extend and keep on extending so their life can be prolonged.

Sue Nelson: So at the end of a quarry's life what normally happens?

David Payne: Normally, these days, modern conditions are attached or legal agreements so the company that digs the material out has to restore it generally to something that fits in with the landscape. Now, that can be agriculture but more often than not these days it is wild life.

Sue Nelson: And that's exactly what happened here because this quarry actually used to be over a much larger landscape and adjoining the quarry is the Paxton Pits Nature Reserve.

David Payne: Well most of the site now is actually a nature reserve. The site has been worked since the second world and it has been gradually restored to a range of uses and you've got a range of habitats.

Sue Nelson: Well let's head over to the nature reserve now where we will meet several more people who have got a vested interest in its success. What a difference between masses of gravel and noisy diggers to what is now a very serene lake with water lilies, bulrushes, birds flying overhead, it's absolutely beautiful and Jim Stevenson you're a senior warden at the nature reserve here. It's hard to believe but where we're standing now, by this waterside, this was once a quarry.

Jim Stevenson: It is hard to believe. This is actually the star lake. It's really filling itself in. We've had bitterns in here, we've got otters in here and there's a good chance of seeing a grass snake today or a kingfisher flying past.

Sue Nelson: And over past the hedges here and the briars and the wild rosebushes was this also quarry land, the meadows?

Jim Stevenson: Yes, that's what we call backfill. That was backfilled to restore it to agriculture really and then it became the nature reserve. It's the heart of the nature reserve really.

Sue Nelson: And we're joined by Helen King from Cranfield University. Helen, you've been working on a report that's about to come out on ecosystems services and particularly part of it relates to quarries. First ecosystems services - it sounds very corporate and jargony but what does it actually mean?

Helen King: It's really looking at the entire workings of ecosystems, so it's a bit of a shift from in the past when we would consider land in terms of the natural resources static kind of materials that the land could give us, so minerals or timber or food. The ecosystems services approach is looking at all the processes that are happening, and the services that nature provides us that effectively we're getting for free so it's trying to formally assess these so that we can bring them into our decision making processes and make better decisions relating to the environment.

Sue Nelson: So how do you apply your eco-systems approach then to a quarry?

Helen King: With respect to quarry restoration there's probably three ways that you could integrate an ecosystems approach. One would be in the planning stage of what you're actually going to set the land up to do. One would be in the management of the restored land, so to encourage the generation of different ecosystem services and then one would be to actually measure or value the ecosystems services that a restored quarry is providing so that you can then use that to see how ecosystems services are going up or down or use it as a communication tool to show other people what services a piece of land is providing.

Sue Nelson: Cas Jewell, you work for Nature After Minerals, now this is a partnership between Natural England and the RSPB. When you see an area like this, this must be exactly what you're after.

Cas Jewell: It is and it's a fantastic example of what restoration can provide for wildlife. Just on this nature reserve alone we've got habitat creation of reed bed wet grass and lowland meadows, all key priority habitats working towards the England biodiversity strategy for working up to 2020. It's providing benefits for both wildlife but not only wildlife but also for local communities and today walking round we've seen people with their children coming to have a look at wildlife, we've got school groups doing pond dipping, bird watching. This just shows some of the ecosystem services that quarry restoration can give not only nature conservation but also health and wellbeing for local communities.

Helen King: These kinds of benefits we would refer to as cultural services, so this is things like mental relaxation, education, our understanding that we get from nature and there are three other ecosystem services that are also in the approach. You've got provisioning services which is food, materials, timber, and minerals. You've got regulating services which are things like water cycle, air cycling, pollination, carbon sequestration, these kinds of things. And then you've got supporting services that underpin the other ecosystem services and these are your bio-physical processes - soil regeneration and this kind of thing. So that's the basis of the ecosystem services approach, these four different types of ecosystem service.

Sue Nelson: You mentioned soil regeneration there. Cas, you are Nature After Minerals, how easy is it to get nature after a site or quarry which is full of minerals completely bare, no green in sight to then being transformed into something like this because it doesn't happen overnight.

Cas Jewell: It does and it does. One thing we're keen to promote is that you can actually have wild life before, during and after extraction. Following the working life of a quarry depending on the depths of material that have been extracted it's quite easy to reshape the hole that has been formed and sometimes the use of inert fill to bring levels up or just utilising the overburden that remained after extraction and then looking at either natural regeneration for party habitats such as heath land it is very simple for heath land just to regenerate on its own. You can create re-bed nurseries actually during extraction in some area that isn't being worked and these can be used to populate the edges of the water body or whatever landform you may have.

Sue Nelson: David, the Mineral Products Association is one of the key partners working with Helen on this report. What are you going to do with her recommendations and her findings?

David Payne: We're going to use them to really educate our members and make ecosystems services, which as you have already said is quite a grand sounding title, translate it into simple language I think for companies to use, really highlighting that what they do already delivers a wide range of benefits and also the benefit that might give them when they are, for example, applying for planning permission for a new site and they need to think about the benefits that's going to deliver, the wider benefits, right from the very beginning but also it will be important for engaging various communities to demonstrate the benefits that are going to be delivered through the working of the quarry but also its restoration.

Sue Nelson: Cas, how will you use Helen's research?

Cas Jewell: We will use it as a building block for some work that the RBSB is doing that is being funded by the European Union. We're looking at going onto quarries and using a toolkit to actually measure ecosystem services and working with partners across North West Europe and we will be looking at trying to put some kind of relative economic value on different restoration end users which will hopefully help operators in their planning.

Sue Nelson: Helen, it's quite amazing isn't it to know that a report that you're doing is going to have an impact and almost quantify what's being done and add quality to it and set an important set of rules or foundations for how a nature reserve like this can come out of a quarry.

Helen King: I really hope so. I think that quarry restoration has a massive potential in relation to the eco-systems services approach. The restoration work is ongoing. It has been going on for a long time and the companies are already familiar with having to create these kinds of habitats and working with the Nature After Minerals project. I think what will be new is giving them the opportunity to be able to record, assess and communicate these benefits to the wider public and to policymakers because some aspects of quarrying I think are still... our image of it is a bit stuck in the dark ages. We think of the noise and the dust and this kind of thing but there's a huge amount of good stuff that comes out at the end, so if you've got somewhere representing this and getting it across to people then that can only help us all.

Sue Nelson: David Payne from the Mineral Products Association, Cas Jewell from nature After Minerals, Jim Stevenson from Paxton Pits Nature Reserve and Helen King from Cranfield University, thank you all very much for joining me in this beautiful and it is a stunning nature reserve, and you can see some pictures on our Facebook page and via our Twitter feed. I'm Sue Nelson and this has been the Planet Earth podcast from the Natural Environment Research Council.