November 30, 2022
Following John Varley's 2018 review of Network Rail's vegetation management practices, six recommendations were developed that would improve the management of Network Rail's lineside estate, should they be implemented. Consequently, investment was made in a pilot habitat management project within the Kent Route to test and evaluate various lineside vegetation management techniques aimed at enhancing biodiversity, while still maintaining a safe and effective railway.
Since 2020, our environmental team has been responsible for carrying out the chosen vegetation management techniques, as well as the ecological assessments and monitoring, in order to provide comprehensive results of the trials, which will ultimately help shape the future of vegetation management and biodiversity across the network.
We caught up with ecologist Dr. Sam Kelly to find out more about the project
The main aim of the project is we are trying out different techniques to see if we can enhance the lineside estate, for wildlife for invertebrates, for mammals for a range of different species, and reptiles, which we also have on these sites.
The reason we're doing it is in the past, there has been quite a high focus on making sure that all of the vegetation, all of the habitat is really cleared all the way to the fence line on these sites.
So we're now trying to come back from that to try and see what areas of the lineside estate we can retain, what habitat features can we keep for the animals that live here and the plants that are here, and which areas we can maybe enhance so that we can have a greater range of species which are living in actually quite large areas of lands all along railway lines.
So each of the sites that we're working on, are about 200 metres in length and they range from anything from 7 metres in width from the rail itself, up to the fence, anything up to maybe even 20 or 30 metres. So some of the sites, we've got quite wide sites, some quite narrow.
And we've got a range of different habitats on the sites, and the sites were chosen for that reason so that we've got a mixture of grassland sites, a mixture of sites, which have just literally bare ballast through to some sites which have got wetland ditches, even ponds, reedbeds, and woodlands as well.
There's a very big focus at the moment on making sure that any developments or any works end up with a net gain in biodiversity. And the the new biodiversity metric 3.0 provides a way of measuring nature losses and gains resulting from development or changes in land management. So as well as carrying out surveys to identify the habitats and species that are here, we've also done an assessment to see what the baseline score is in terms of biodiversity.
And what we're going to do is try different habitat management techniques in each of these sites, to see which of those techniques actually enhance the sites more for biodiversity.
The habitat management techniques that we're trying out are designed to work with the habitats that we have on the railway. So they are quite varied, we do have a lot of grassland, so some of the habitat techniques that we're trying out will enhance the grassland that we've got. Some of them will try to convert it to a different type of grassland or just try to incorporate different plant species into the mix that are in the grasslands that we've got, which will benefit all sorts of invertebrates and all the other creatures which then feed on those.
We also are trying out brownfield enhancement because some of the sites have quite a lot of ballasts, a lot of stone, and they're quite harsh environments, so we're trying out different seed mixes on those to see if we can get plants to establish on what is essentially quite a harsh environment.
We've also got techniques that focus on scrub management. Sometimes we're trying out enhancing the scrub by diversifying it, planting different species in it and cutting it and rotation and opening up glaze in it.
We're also trying out techniques which enhance woodlands. So again, creating glades incorporating more woody species into some of these sites. We're also trying out traditional forestry management techniques which enhance woodlands. So again, we're going to be opening up glades and woodland to let some more light in, some of them are very shaded, we're going to be planting a greater diversity of understory species to try and enhance the woodlands themselves for species richness inside.
We're also looking at habitats which are outside of the lineside. There's a lot of woodland adjacent to the lineside estate, so we're trying to work with the landowners on the other side of the fence as well to see if we can work with them to enhance what's here to help what's off-site as well and become an extension of that.
For the next few years we'll be coming back, we'll be monitoring to see what's happening on the sites. We'll also be doing maintenance on the sites to remove any species which are starting to reestablish which we don't necessarily want to dominate the sites, making sure that everything is kept in check.
And then hopefully, at the end of the project, we'll be able to see clearly that we've enhanced the sites for wildlife, we'll be able to see which species are benefited, we might even see which species didn't do so well and that will inform how we go forward with managing the lineside estate across the country, which techniques will be better invested in and which ones will give us more gains for biodiversity.