Debris Dams

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Thank you to HKD Transition for restoring the debris dams in Lag Wood – and creating a few more! Debris dams are made from fallen small trees and branches and sometimes any other natural materials that come to hand. They are simple to make and are held in position by a few stakes in the stream bed. They are designed to slow down the flow of water in the upper part of river catchments to prevent sudden flooding downstream at times of very heavy rainfall. For most of the year they let water flow freely.

Debris dams can have many ecological benefits, they increase the variety of aquatic and semi-aquatic habitats and can improve biodiversity as a result. They have very few adverse impacts because they mimic what happens naturally in woodland streams. We now have six of them in the wood; three in the stream bed and three along several of our old drainage ditches.

For more on HKD Transition please see

South Downs Volunteers


A great big thank you to SNDP lead ranger Phillippa Morrison-Price and her trusty team of volunteers who spent the day cutting back bramble on the meadow margins. It was a pleasure working with you in the meadow and really good to see you all. You can follow Phillippa on Twitter at @Ranger_sdnpa

The Woodpile and the Stile


The giant woodpile is now a lot smaller, thankfully. We have scythed the brambles and thistles from the surrounding area as part of our plan to return most of this area to grassland. Unfortunately the contractor came into contact with the stile near the stream and was forced to dismantle it. We’ve contacted the Monday Group who will install a new one in a few weeks time when the rest of the wood piles have been removed. Meanwhile, we have a temporary gate where the stile used to be.


Chalara Ash Dieback Survey


Ash tree with leaf loss from the margins of the crown – a typical symptom of Ash Dieback.

In mid June we surveyed all the ash trees in Lag Wood to see how many were affected by Chalara Ash Dieback. We found 102 ash trees showing symptoms of the disease. This represents nearly a quarter of the ash trees and ash coppice stools in the wood and shows a considerable rate of advance for the disease considering that we first identified it here on a few re-growing coppice stools in summer 2016.

Chalara is fatal to a large majority of ash trees but there is some natural immunity and, even when infected, not all ash succumbs to the disease. Estimates of survival rates vary depending on the density of ash in any given location. Mixed woodlands like ours tend to show slower rates of infection.

With no reliable means of prevention and no cure, our options for managing the disease are extremely limited. We expect a very large proportion of our wonderful ash trees will die in the coming years.

We have already felled ash where we felt they posed any risk to the railway line. We may also fell ash where public rights of way could be affected. But in other instances we feel we have few options except to let nature take its course. Ash makes up over a quarter of the larger trees in Lag Wood and nearly a half of the woodland canopy. The character of the wood will change significantly over time, and there is no doubt that there will be an impact on species because ash supports such a diverse community of plants and insects.

However, the gradual thinning of the canopy will allow more light and warmth into the wood. After coppicing here for five seasons we know something about how the wood will react. Wildlife friendly tree species like hawthorn, field maple and hornbeam will be the main beneficiaries. We will also see the regeneration of birch, aspen and, most welcome of all, oak seedlings. Ash itself will also continue to regenerate and a few of those seedlings will have greater immunity to Chalara.

We are adjusting our coppicing plans. We are likely to avoid coppicing any more healthy ash and we may put greater emphasis on rotational Hazel coppice. We will keep up our use of temporary deer fence to protect regrowth and continue to monitor the progress of Chalara and how the wood is responding to it. It is a poignant and melancholy moment for us as it is for all those who love woodlands. But it is by no means a disaster for the wood as a whole. If you’ll forgive the pun, a new beautiful Lag Wood will emerge over time from the ashes.