Planet Earth: Future-proofing
Alan - Forests cover almost 1/3 of the Earth's landmass and play a key role in the health of our planet. They regulate climate change by removing carbon dioxide from the atmosphere through photosynthesis and storing the carbon. Planet Earth podcast presenter Sue Nelson meets Dr. Karsten Schönrogge from the Centre for Ecology and Hydrology in Wallingford. And she began by asking about the meaning of a current buzzword with regards to climate: future proofing.
Karsten - Well, we're talking about particularly commercial forestry where foresters are concerned with the fact that plantations they put down into the ground today have a turn over time from 50 years, 80 years, sometimes 100 years and so the trees that they are planting now will experience the climate which we expect to be here in 1,500 years. So, the question is whether current planting strategies to source the seed material locally is actually the best strategy there is. Future proofing might mean to go to areas where the range of the plant they are interested in which today experience a climate which we expect here in the future.
Sue Nelson - When I think of forests I think of spruce and pine and the sort of forests you might get in Germany, for example. What sort of forests are you, in particular, thinking of - what sort of trees?
Karsten - Our project is particularly aimed at sessile oak trees which is one of the two native species which we also have here in Britain. These are hardwood trees and there is a particularly interest to grow these trees for the timber industry; it was also THE tree in Europe which supports the highest biodiversity. On oak trees we would find across Europe possibly 700 different species of insects which is by far more than any other tree species that we have.
Sue Nelson - Now why can concern yourselves with insects, for example, when you think of the amount of carbon stored by trees that if the forests are removed then surely it is more worrying about the amount of carbon that is released into the atmosphere rather than, say, an insect species go extinct.
Karsten - Forests are, of course, not an isolated system by itself and insects in forests might be pest insects and actually damage the function that we want or there might be predators of pest insects and therefore it would be beneficial to ecosystem services which we might want to promote.
Sue Nelson - So how do you go about future proofing in terms of an experimental way? How do you determine whether oak trees will be able to withstand a change in climate?
Karsten - On our project we were inspired by a particular strategy which was published in the literature called climate matching and in climate matching scenarios we used forecasts for climates to be expected in the UK in 50 or 80 years and we look for areas across Europe where that climate already exists.
Sue - Okay, so what will the UK be like in 40 or 50 years? Which climate does it most match?
Karsten - It will depend on whether the carbon dioxide output will increase with no further limitations or whether we have a low CO2 scenario but the matching areas for, for instance, southern England, the Bordeaux area in France and a low carbon dioxide scenario but central Italy for a high CO2 scenario.
Sue - That's quite a difference.
Karsten - It's quite a difference and we expect those trees to perform well in 50 to 80 years but of course as they go in the ground now we might expect them not doing very well.
Sue - So you've planted some oak trees then in a specific area in northern France, what are you actually looking at then in terms of determining whether the oak trees are doing well or not?
Karsten - The trees were planted by collaborators of ours in France - an organisation called INRA - it's the largest trial of its kind. It's a million trees in four locations and we work in one of them, so 250,000 of them and we looked at trees which come from 20 different locations in Europe as far away as Ireland and the west, Denmark in the north and Georgia and Turkey in the south. Our colleagues at INRA look at every single tree and scored them for the time of the year when they come into leaf, they scored them for the growth, for the form they grow in, how many branches they have.
Sue - What did you find?
Karsten - So our first interest was whether these trees are locally adapted to the climates in the area where the seeds came from and there's strong evidence that these trees differ according to the place where they come from. So second then was whether we can take the phenotypes of all the different rose parameters and the time when they come into bud and to leaf would determine the insect communities which are associated with them, and that seems to be true as well, in fact we can take a step out, we can take the climate variables from the places where these seeds came from and we can predict how different these insect communities might be. The more complicated part of all this is to predict exactly how the communities differ and too possibly make a prediction about actual species of insects and whether they might become more or less abundant when they are feeding on these foreign povenors as we call them, oak trees.
Sue Nelson - So who is going to be most interested in the result of your research?
Karsten - Well we hope that both the forestry community who makes plans as to who what good planting strategies are would be interested but also the conservation areas of the biodiversity sector in general.
Sue - So better forest management will come out of this in order to effectively protect future forests - future proofing - there's that word, future proofing.
Karsten - Absolutely.
Alan - Dr. Karsten Schönrogge from the Centre for Ecology and Hydrology in Wallingford. And you can hear a longer version of that interview on the current edition of the Planet Earth podcast. Simply follow a link from our webpage or find it via Planet Earth online.