What lies underneath

Friday 2 August 2024

Climate and wildlife

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With both ecological and climate crises unfolding before us, our climate and wildlife blog will explore aspects of this as well as the difference that organisations and individuals can achieve.

Eades Meadow by Paul Lane

Climate change and wildlife officer Jack heads out to some of our nature reserves to see how much carbon they are storing...

Big Meadow at The Knapp & Papermill by Paul Lane

Throughout the last month I’ve been out and about across our meadows and grasslands sampling the soil to see how much carbon they’re storing.

One way to help the Trust achieve net zero carbon emissions by 2030 is to increase the amount of carbon that we can store within our own nature reserves. This isn’t just an ambition for the climate; storing carbon can also benefit the health and ecology of the reserves too. Carbon becomes stored in the soil through organic matter - all the material that came from living organisms, such as roots and decomposing leaves. As a rule, the greater the amount of soil organic matter, the more carbon is being stored in the soil and the more nutrients will be released by the activity of soil microbes. Conventional management of species-rich grasslands, however, usually requires nutrients to be depleted in order for a diversity of wildflowers to thrive and not be outcompeted by dominant grasses. So it’s important to test the soils to see if they contain the right amount of nutrients and organic matter.

Soil auger — A soil auger that is used to collect a sample by Jack Reeves

I headed out to places such as Big Meadow at The Knapp and Papermill as well as Eades Meadow to take soil samples that were then sent off to be analysed. To take a sample I used an auger to drill down 30cm into the soil at a random place in the meadow; when extracted this provided a core of soil. This was repeated until I had a representative sample and then I mixed the samples together and sent off 300g to the lab. There was quite a range of soil organic carbon and nitrogen across the sites. A good level of total carbon stock is around 113 tonnes per hectare and three of the four grasslands I sampled were above this. So even from just a few sites we’re already storing a lot of carbon in our soils; more sites will be needed to see if this representative for all our meadows.

Not only does more organic matter improve the nutrient quality of the soil but it can also help with improving water retention, acting as a sponge layer in the soil to hold on to water during drought and reduce rapid run-off during a flood. Along with the soil type, this can be a good indicator for how well soil can help for these sorts of weather events. If you know the soil type in your own garden, you’ll probably already be aware of how well water drains in your garden during heavy rain. When it comes to improving the soil of your gardens and green spaces, adding organic matter is a great way to get more nutrients into the soil and feed the soil microorganisms that thrive there. As well as adding organic matter, reducing the compaction of the soil will help the roots to grow and planting ground-cover plants will also help to reduce soil run-off and hold more water. Always remember to avoid using peat in your gardens, whether in a bag or as a growing medium for plants that you buy, as this is a vital habitat and carbon store.