I delivered three sessions of the new Kew Diploma this week, and felt quite tired at the end. As I reflect on what was involved, I now realise why! Each four-hour session takes me 24 hours to prepared and write!
The sessions are being well-received. My most recent session was exploring the role of the xylem vessels that transport water from the roots to the shoots. The tree only uses the vessels for a short period, and new formed are formed on the outer part of the trunk.
Some trees form larger vessels on the spring and smaller ones later in the year. This forms a distinct pattern in the wood, known as the annual growth ring. Trees which do this are called Ring Porous, and include Oaks and Sweet Chestnut.
Some trees form vessels of the same size throughout the year, without the distinct annual ring pattern. These are called Ring diffuse. They include Beech, Horse Chestnut and Birch. What is interesting is that ring porous form heart wood and are better at resisting heart wood decay.
Whilst I am enjoying the teaching, and the students are enjoying it, and are receptive to the material, I have to remember that I am only delivering a small part of the curriculum and not to go in to too much detail!
The audit of the collection is progressing well. I have now completed the Beech, Cedar and Limes.
At this point in time, we now know there are 1220 Oaks in the collection – not including natural area; 181 Ash in the collection not including natural area; 147 Cedar trees; and 59 Elms and Zelkova in collections.
With each tree recorded, the position it occupies is noted. With this information, we know how the various collections are distributed across the Gardens We can also identify when trees are dying and being replaced. We can see with some trees a pattern emerging. With some species, we have been propagating the tree by seed or cutting and growing the replacement in our nursery. Then when the parent dies, the new tree is ready to replace it. The problem is that some of the species are not suited to their setting, and we need to select a different species for that position.
This year, filming for Channel 5 is taking a different approach. Footage is sent to the editing suite as soon as it is recorded. I am working on a feature to be shown in June this year! It is much harder this way, with more time spent in preparation, but still enjoyable. The theme is the history of the site, and we are exploring the historic vistas, including Sion Vista, which is a UNESCO heritage site and protected from development.
Finally, to my disappointment, work on the ‘Trees in Motion’ project has been delayed, as we wait for the sensors to arrive. The good news is there are plenty of other projects to work on as I wait.
Teaching, filming, and even some surveying; life at Kew is certainly packed.