20 October 2017

Tony Kirkham shares his passion for trees with Dame Judi Dench

Tony Kirkham, Head of the Arboretum and Dame Judi Dench have filmed a new ITV documentary in Borneo. Here he discusses their shared passion for trees at Kew.

By Tony Kirkham

The Arboretum, RBG Kew

Sharing a passion 

It was a true privilege to discover Judi’s love for nature, and spend time with her thinking about the role of trees in our history and in our future, the science behind how they work and communicate to each other.  

As well as tiring long days of filming, it was also really great fun and we both learnt a lot from one another. We had lots of laughs, particularly about Lancastrians and Yorkshire folk and there were some poignant moments that didn’t make the screen. 

I’ve always had a great passion for trees, ever since playing the game conkers as a boy, building dens in woodland and climbing what I thought were the biggest and best trees in my local park back home in Darwen, Lancashire. When I was at school I decided that I wanted a career working with trees in some way and I have since spent my working life studying, understanding and caring for trees. 

After a short career in the forestry and arboricultural industry I came to Kew to do the 3-year diploma in horticulture and have been here at Kew since, for almost 40 years, looking after our Arboretum of 14,000 trees. 

Researching the life of trees 

We have a large team of scientists working at Kew, researching, mapping and identifying trees and it was great to be able to share some of Kew’s research on the programme.  

As we journeyed through the seasons we identified some of the different ways in which trees prepare for the different climates. Even in winter it’s good to know so much is happening underground with fungal associations with trees. 

Trees communicate in a number of ways. Remember that they come from forests and woodlands where they grow together in communities, rather than isolated specimens. They are all connected underground which is truly fascinating.  

Trees help each other, they grow together and nurture each other. They are a real community that help each other, us humans and the planet. 

On-going research at Kew is revealing how closely trees and fungi work and live together. Most of our temperate trees latch on to mycorrhizal fungi (which mean fungus roots). In exchange for sugars, these fungi transfer nutrients and water to the trees, improving their growth and survival and protecting them against pathogens. Mycorrhizal fungi can connect individual trees underground forming a common network of nutrient and water transfer that affect the survival and functioning of forests. 

We use this research to help us with the cultivation and management of our trees at Kew. You’ll see large, mulched circles around the trees. What we’ve done there is we’ve aerated the soil around the root systems and put organic matter on the soil surface. Basically we’ve mimicked a woodland floor and made the ambient conditions for this mycorrhizal fungi that can help support tree networks. 

Looking at trees in a different way 

There’s so much we don’t know about trees and we are discovering more and more and learning all the time; we should never take them for granted and we need to give them the respect that they rightly deserve. 

I hope the programme inspired viewers to learn more about our trees, to look after them and take care of them and that they will walk through a woodland, park or even their own back garden, and look at trees in a different way. 

Watch Judi Dench's Wild Borneo Adventure on ITV, 2 July 2019