Taking a leaf from mother nature

IF THERE IS one thing that makes tree huggers furious, it’s the constant abuse of the all-too-few large trees that still line the city’s streets and help absorb the carbon dioxide constantly being emitted and inhibit climate change. 

Many trees are mutilated at the roots while others are paved over with concrete. Most are poorly trimmed, their branches chopped off without any consideration for the tree’s health or aesthetics. In short, the Thai capital is dire need of arborists and this is where an association known as Urban Tree Care is coming to the rescue.

Founded in 2014, the group has been educating and training tree lovers to properly handle and trim big trees with support from several concerned groups and arboricultural experts, including Assistant Professor Pavadee Ansusinha, head of the Department of Landscape Architecture at Chulalongkorn University. She sat down with us recently to talk about our trees and what we can do to save them. 

 

WHO IS URBAN TREE CARE? 

Our efforts come from an ensemble of five parties. Somdet Chaophraya Institute of Psychiatry and the Department of Landscape Architecture provide the theory and knowledge, while Tharadol Thanduan, Thailand’s most renowned arboriculturist and a pioneer in urban forestry, handles the demonstrations and learning by practice. Big Trees Project is a group that raises awareness of green space and care among the public while PPT helps out |by funding some of our |training and other activities. |The Thai Association of Landscape Architects recently signed on. 

Our mission is simple. We want to educate those working with trees in big cities, or anyone interested in arboriculture on the correct and proper ways to trim trees, which will benefit all those of us who live in the city. 

 

WHAT PROBLEMS HAVE YOU SEEN SO FAR? 

When we first started it was more about maintaining a presentable landscape. We found trees that were badly trimmed, incorrectly pruned and such, and some guidance was needed. But recently we have seen bigger problems of uprooted trees as well as trees that are dead or dying while still standing. This poses a much more serious threat to the wellbeing of the trees, especially in Bangkok where new developments are constantly being built and a lot of trees are destroyed in the process. And even in the developments themselves, trees are not trimmed with correct understanding and care.

 

HOW DO YOU TRIM TREES PROPERLY? 

The biggest and most common mistake is trimming trees during the rainy season. It makes sense to us because it is the season when problems of obstruction of public space by trees are more prominent. We’re afraid that the monsoon storms will bring down trees. But the rainy season is when the roots of the trees grow the most. They are expanding both on top with the branches and down below with their roots. Cutting the branches when food and nutrients are being collected weakens the trees, stopping them from expanding their roots to cover more ground and holding themselves more firmly in the earth. We have been doing this for many years and the negative effects are now starting to show, with trees falling because they are weak. 

Trimming a tree is very similar to grooming a dog. You wouldn’t give a poodle the same hairstyle as you would a Chihuahua. Trees are different, too. Each kind of plant has its own way of growing, branching out and expanding, so if you have some knowledge of the tree you’re handling, it’s a great help. 

 

IS THERE A WAY OF KNOWING HOW MUCH TO CUT OFF AND TO LEAVE ON?

That’s another big problem. People tend to trim the trees at the very top, chopping the head off, and ridding them of as many branches as possible because they don’t want to have to trim them again any time soon. But this only encourages the trees to grow more twigs and branches on the sides, and soon they’ll get messy, tangled and even more difficult to trim. Trimming a tree is like thinning a thick head of hair. You get rid of the intertwined branches, the ones that are too heavy for the trunk and just thin the foliage while keeping the tree’s original form for it to continue to thrive naturally. You need a trained eye to see how much you can cut off, based on the health of the tree and several other factors. 

 It gets tricky when you have to get rid of branches that grow into electrical and phone wires, and this is very common in Bangkok where trees are planted on pavements under the electrical poles. You can’t just chop off half the branches on a tree and hope that it could maintain balance on its own. You need training, first to save yourself from getting electrocuted, and second, to trim the tree without killing it. 

 

SOME TREES HAVE WOODEN CRUTCHES PLANTED AROUND THEM FOR SUPPORT. DOESN’T THIS HELP?

It would if the trees in Bangkok had taproots that go way down deep to support themselves. Trees with taproots are much stronger, and they can recover with the use of crutches. The problem is that big trees in Bangkok are transplanted to the site when they are already big. They do not grow from seeds so they cannot have taproots, unlike trees that grow in farms or forests. Trees in Bangkok have very limited lateral space and depth for their roots to grow. On the sides their roots hit pavements, concrete, building structures and pipes. And their roots can’t go very deep, so only their lateral roots grip onto the shallow ground. Crutches are not the best solution because eventually the trees will fall. 

 

WHAT ABOUT SNAGS? 

Snags are badly wounded trees that cannot heal themselves. There are ways to cut the branches without exposing the trunk to infection. The correct way leaves the cut neat with no ripping or tearing of the bark, allowing the tree to grow more cells to cover and heal the cut. If the trunk is infected, the wood inside will start to rot and die, and it goes all the way down to the roots.

 

SO STAFF FROM BANGKOK’S DISTRICT OFFICES DON’T HAVE THIS KNOWLEDGE?

Some do, but most do not. Trimming trees falls under the responsibility of the cleanliness and public park unit where the staff also collect garbage, clean public toilets and archaeological sites if any, empty septic tanks at houses and even relieve public dangers. They don’t specialise in handling trees. Some offices may not have the budget or the time to send their personnel for training. Some are sent to train with us, and we hope more will come, or at least spread the knowledge they have gained to their colleagues. 

 

WHO IS THE TRAINING PROGRAMME FOR?

It is actually for anyone who is interested, fit enough and not scared to climb high trees. Our training has a lecture component but it focuses mainly on the practice, so you will learn how to tie knots, how to climb and handle equipment as well as first aid. We also have a guest speaker from the Metropolitan Electricity Agency to talk about how to handle working close to electrical wires as well as other experts in arboriculture. A lot of participants are working in the field of landscape architecture, both for private and government agencies. No background knowledge is required, and everyone is welcome. 

 

The right cut

- Urban Tree Care is hosting its fifth arboricultural training on July 29 and 30 at the Faculty of Architecture, Chulalongkorn University. The cost is Bt4,000 per person, inclusive of lunch and a certificate upon completion. 

- Applications close on July 19. Call (02) 218 4339 and (086) 994 1839 or email [email protected]

- Find out more at Facebook.com/ ThaiUrbanTreeCare.