Our trees in the drought

How are The Carbon Community’s trees coping with the drought conditions? We take a look at some of the trees planted earlier this year and how they’re faring in this heat.

We are frequently asked why we chose Wales for our flagship site where we have both our landmark carbon sequestration study, and have created a 40 hectare new forest. As a UK charity we operate at a national level, but Wales is particularly special to us, and is a great place for this kind of scientific research, especially from a climate point of view. Looking at climate modelling for the UK over the next 50 years shows clearly that the south east of the UK becomes hotter and drier, while Wales becomes warmer and wetter – and therefore better for growing trees and studying carbon sequestration as the climate changes. In this drought the contrast with the south east, which is dry and parched, and the still lush green fields of Wales has been marked.

Of course, there were other reasons why we picked our site in Wales: a friendly and supportive community, forest skills locally, and great Universities in the area focused on the Environment and Forestry, notably Swansea and Bangor, which we work closely with. But above all, our site is a special place, spectacularly beautiful as everyone knows who’s volunteered. If you haven’t been on one of our volunteering days, we’d encourage a visit: its good fun, you’ll meet interesting people, and help to make a real difference in the climate emergency.

Our New ‘Fall Colours’ Wood

In March of this year we planted a new piece of woodland focused on autumn colours. A mixture of 900 Red Oak, Beech and Sweet Chestnut were planted by volunteers over the course of a weekend. The setting for this patch of woodland is very pretty with views towards the Brecon Beacons, and we wanted to celebrate the location, enhance the views and create a woodland that would be spectacular in autumn. It was a lovely March day with sunshine, and we were working in the sun in shirtsleeves. For those of you that came and planted with us, I’m sure you'll remember the day and have been wondering how these trees are faring – the following month of May was dry, followed by extreme heat in July and August.  

The good news is that the trees are thriving. There’s been just enough rain, and the combination of the weather, location and ground water have led to a very successful establishment of what will be a spectacular wood for generations in the future to enjoy.  All three tree types are thriving: the Sweet Chestnuts – which looked dead when we planted them – are doing especially well.

When we planted this woodland, we used our ‘soil biome injection’ technique. This is one of the approaches that we are testing in our Carbon Sequestration study which we can see already showing great promise.

In simple terms, we harvest a small amount of soil from existing woodland which we then add to newly planted trees before closing up the hole and heeling in the new tree.

You might think this is very damaging to the existing woodland, perhaps envisioning a small quarry type of operation, but this is not the case: we only harvest a very small amount of woodland topsoil, up to 20cm, and cover over the area again with leaf mould. Four months later its hard to see where the donor soil even came from.

Injecting mycorrhizal fungi

The idea behind this technique is to transplant the complete soil biome from the existing woodland to give the new trees a jump-start in their new homes. The woodland soil is very different from the soil in the planting area – its much blacker, richer, and critically is teeming with mycorrhizal fungi.  By putting this soil in the planting hole, we accelerate a natural process that would otherwise take decades where a vast array of specialist fungi develops over time to help trees to absorb the nutrients they need from the soil. This should make the trees grow faster, be more resilient to pests and disease, and hopefully to drought conditions. While its too soon to know for sure, based on the trees planted in April, it looks promising.

Planting endangered Black Poplars

In April we also planted 40 Black Poplar trees from cuttings which were donated to us. The female Black Poplars are endangered in the UK, with only about 600 remaining in the wild, so it’s important to create a new cluster. The cuttings were about 40cm high with buds already on, and no roots, though some had root nodules beginning to form. We planted these straight into the ground into a slit and firmed them in, specifically selecting wet ground which they prefer. While we have lost a few, the majority are thriving which is great to see.

As you can see in the photo, this volunteer planted Black Poplar is now at least double its original size at planting in only 4 months. The bracken is also doing well – so there’s some work we need to do here!