Monitoring Monkwood

Dom discusses how we are measuring changes in the landscape at Green Farm...

With two years of restoration already underway at Green Farm, we can start turning our attention to monitoring the changes that are happening. There are loads of things to survey and plenty of ways to do it! But, with not much time or resources, what do we prioritise? What are we monitoring against? And what are we hoping Green Farm will change into?

The first thing to do with any restoration or habitat creation project is to do baseline monitoring at the very start, which gives you an idea of how things are before you start doing anything to reach your end goal. For us, we want to measure biodiversity and bioabundance, with the aim that both will increase as the different habitats at Green Farm develop. To do this, we could look at a whole range of measures, from soil bacteria to the number of nesting blackcaps, water quality to abundance of hawthorn in the hedges. Eventually, we decided to prioritise valuable habitats, key species and key areas of change.

Hedge stretching away in the distance, with leaves just starting to change colour by Paul Lane

Valuable habitats

First off, some of the most valuable habitats when we first acquired Green Farm were areas of species-rich meadow, rich and ancient hedgerows and six veteran trees.

We’ve logged all of the veteran trees on maps so that we know exactly where they are and each has been given each a general health check. The largest is a wonderfully craggy oak that has grown to over 4.2m in diameter over several hundred years.

We’ve also assembled a list of plant species found in all the hedgerows and meadows across the site, which not only gives us a baseline to work from but also shows us which areas are the most ecologically rich. To date, we’ve recorded over 145 different species of plants on Green Farm; 25 of those are in the hedgerows alone. Our surveys have shown that the top of Long Meadow is the best grassland, with plants like adder’s-tongue fern, goat’s beard and yellow rattle.

This gives us a great data set to compare to in years to come, when hopefully the veteran trees will be joined by veterans of the future, hedgerows will be extended and re-connected to Monkwood and the specialist plants that make up the species-rich parts of the meadows will have expanded into new areas.

Key species

Next, it was important to gather evidence of our key species. This list of species was based on notable species that had been found at Green Farm as well as star species within Monkwood that would likely benefit from habitat diversification across our new landholding. These included hazel dormice, breeding warblers like blackcap, willow warbler and garden warbler and butterflies such as wood white, marbled white and silver-washed fritillary.

Breeding bird surveys were carried out in the spring of 2022, just before our restoration started. 30 species of bird were recorded then and this list has since been added to with hobby, redstart and meadow pipit. Over the last month we’ve also recorded stonechat, which is the first record ever for Monkwood. This juvenile male was clearly benefitting from the long grass in the new orchard at Green Farm – a habitat that has been created through our restoration work. We’ll repeat these bird surveys regularly to document changes when there is more scrub, more wetland areas and growing woodlands.

To look for hazel dormice, we’ve been using footprint tunnels in the hedge network at Green Farm. Inside the tunnel there is a natural ‘ink’ (sunflower oil and charcoal) and paper, with both ends of the tunnel open. The idea is that small mammals walk through the ink and leave their footprints on the paper as they pass through the tunnel. Dormice have very distinctive footprints as their footpads are shaped like triangles. We set up 70 tunnels in the hedges at Green Farm in 2023 but, so far, we haven’t recorded any dormice. Surveying will continue this year, hopefully with better luck.

Two courting wood white butterflies by Ion Riley

A butterfly transect was set up in 2022 with dedicated volunteers visiting every fortnight through the summer to count the different species across Green Farm. To date, we’ve recorded 24 species of butterfly including our target species, which is brilliant. The weather often has a noticeable impact on butterflies and the ones living at Green Farm have been no different. For example, in the dry, warm summer of 2022, 653 meadow brown butterflies were recorded flitting around the late summer meadows. Last year however, in a typically damp and cool British summer that followed an exceptionally wet winter, that number dropped to 247. It’s important that these factors are considered when analysing survey data as population changes are often due to multiple factors.

Key areas of change

Finally, we’d like to monitor key areas of change at Green Farm. This has needed a lot of thought and we’re still pulling together a monitoring plan for this. However, here are a few of my thoughts.

The change from grassland to woodland is obviously quite a visible one. Trees and scrub start small but as soon as they get established, growth happens quickly and in 30 years a young woodland has appeared.

We’re really interested in the more subtle changes, such as the chemical composition of soil. Little Plains, one of the wetter meadows, has got twice as much magnesium in its soil compared to Long Meadow. Long Meadow has got almost double the amount of phosphorus as the Blacklands Meadows next door, which are also slightly more alkaline. For the fields that are transitioning to woodland, we also wanted to find out how much organic content there already is in the soil. It is assumed that as tree cover increases and leaf litter is added to the soil, the organic content should increase over time.

The general changes will be mapped aerially and we’ve already carried out a series of drone surveys to map the different habitats that are currently found at Green Farm. Each year, we will re-map these to see which areas are expanding, which are diversifying under their own steam and which may need a helping hand. Coupled with our species surveys that indicate habitat changes by their presence, we should be able to start building a complex picture of how species are responding to our restoration programme.

Our monitoring plan is by no means set in stone; it will change and flex over the years as we understand more about the ecological processes taking place. Monitoring not only shows us whether the restoration is working to achieve our goals at Green Farm but it also adds to the national picture in the face of climate change and ecological collapse. Some species at Monkwood and Green Farm, like wood whites and hazel dormice, are right at the edge of their UK range here in Worcestershire and are very vulnerable to additional pressures on their populations. If we can understand more about the factors influencing these species and how they respond to change, we will have a much better chance of protecting them for the future.

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