Creating a living lab in Hatfield Forest

As part of our work to help care for Hatfield Forest, we’ve invited world-leading tree and soil experts to the forest to create a living laboratory which will help us understand the pressures on the landscape.

The present problem

Wet and wintry weather presents a particular challenge to the forest’s most worn out paths, where we’re seeing a real impact on the decline of vegetation and wildlife.

We are working with world-leading tree and soil experts from the Bartlett Tree Laboratory.  A number of ‘test sites’ have been created within the forest, on the rides leading from Eight Wantz Ways, to help the researchers understand which methods work best, to encourage biodiversity back into these vulnerable areas.

" It’s not very often that you’ll see botanical research like this happening within an ancient hunting forest such as Hatfield. We’re looking forward to working with the researchers to learn more about which test environments will encourage the right type of vegetation back to the worn out, compacted paths."
- Ade Clarke, Hatfield Forest

Every inch of Hatfield Forest’s 1,000 acres is influenced by human activity.  More and more people each year enjoy the land, outdoors and nature.  This research is important for all of us.

The work we are doing now will help safeguard the future of this ancient forest by encouraging the much needed biodiversity back into areas where the paths have worn down and the soil has been compacted..

One of the soil decompaction test sites
Test area within Hatfield Forest to help decompact the soil
One of the soil decompaction test sites

Project Update  - 2 years on, Nov 2019

The good news is that the test plots are slowly de-compacting. The process takes time on badly affected soils, especially in the early years. Once there’s a critical mass, the process speeds up.  This needs the soil structure to open up enough for organic matter to mix in with it, earthworms to help aerate it and turn it over, and tree roots to begin penetrating again.

The fastest process is where air spading breaks up the surface instantly. This can have repercussions with ancient woodland soils where there is a risk of tree roots near to the surface being affected, so is not suitable around ancient trees or coppice stools.  

The second most effective method is when biochar (inert charcoal) has been poured in to augered holes set at 50cm apart and 50cm deep within the 3X3m plots. Biochar assists drainage and prevents the holes from closing up again. It is a fairly long-lasting solution.

The third best method is where woodchip mulch has been introduced to the holes, which is a cheaper solution but will obviously decompose within two or three years. The augering also assists in drainage because the holes break through the first 10cm or so which is where decompaction is at its worst.  The soil cores taken from the worst affected trial plots had the consistency of ‘brick’ when tested.

Funding-dependant, we may be in a position to use biochar for heavily compacted hot-spots, and then use woodchip on those which are a lower priority.

The fourth method - blanket woodchip mulch covering - is also good at reducing compaction.  It dampens footfall pressure but obviously smothers the soil so very little can grow through it until it thoroughly rots down. This is however a viable option where the vegetation is unlikely to ever come back, where there is excessive footfall and constantly bare ground.  It does however need regular replenishment, to avoid it becoming a muddy mess again.

How can you help?

Find out more here