Taking Trees for Granted

Trees literally keep us alive. Here's how.

Photosynthesis is a magical thing that all plants do but trees are especially efficient at it. It's a process that scientists have understood for along time but haven’t yet worked out how to replicate. It’s a basic formula: 

carbon dioxide + water + light energy  gets converted by chlorophyl into carbohydrate + oxygen + water

There’s a few things going on here but the two I want to point out here is the conversion carbon dioxide into wood and oxygen.

Regardless of whether you believe humans are causing climate change or it’s a natural ice-age thing there’s no denying we have too much greenhouse gas warming the planet’s atmosphere like… well, -a greenhouse. Carbon dioxide is the most abundant greenhouse gas and it’s the one we can influence the most, positive or negative. Trees absorb carbon dioxide (CO2) and turn it into wood. This is known as sequestering carbon dioxide.

Without trees we couldn’t breathe. Out of all the plants, trees are the most efficient at providing plenty of oxygen simply because they have loads more leaves working hard at photosynthesis and they’re all up high on a stick out of the way (a tree trunk) compared to other plants like shrubs and perennials that take up room at ground level - our level.

Every other benefit trees provide us is merely bonus points really. Lets take a look at them.

Greenery has a remarkable effect on our psyche and mental health. It sounds cuckoo but it’s true. Scientists have studied the effect of greenery on mental health patients and found that a simple walk outside to look up at the leaves above can calm a person from a psychotic episode better than sedatives plus it has no negative side effects. How and why it works exactly is still being debated but I think it makes sense when you look at human history over the last few millennia - we’ve never been more surrounded by walls and windows than we are now.

Trees provide the perfect kind of shade on a scorching hot day. Dappled shade is a beautiful thing. Shade from a tree is different to shade from a building too. Because of the shape of a tree but up high on a stick (the trunk) the shade has a more dynamic shape across the day compared to a solid man made shape like a building - the shade is more dense and dank. Trees also balance the moisture content of the air making it perfectly fresh.

Streets make up the largest public space available in any city. So never mind thinking trees can be located in the parks and private property. Trees and wildlife were here first. We should be building our lives around them not complaining about their impact on us. Which makes me wonder why roof gutters are so poorly designed to cope with leaves. Trees and leaves were always here.

Street trees influence the speed we drive. In wide open spaces we tend to drive faster without thinking about it. With trees creating a little enclosure at the sides and canopy we naturally slow down without even needing to check the speedo. That’s what we want for residential streets, slower speeds means safer meat sacks (human bodies).

Trees along streets or private property - any real estate agent and property valuer can tell you that established trees mean better property values. It’ll be interesting to watch what happens to the property values on Chaucer St and Grasmere St over the next few years. The residents working with the Council on the replacement street trees should make sure they insist on tall established trees to be installed.

Wildlife need trees to survive, especially birds. Imagine you’re a bird and you can only take a break from flapping your wings by landing in a tree. How would you need to travel to find food (growing on a tree or shrub) and a place to perch to live happily ever after?

We have a dwindling number of forests and trees across the planet surprise surprise. Just think, the planet used to be smothered with forests and grasslands (and ocean of course). Now it’s quickly being replaced with concrete islands (cities), asphalt arteries (roads and highways), chuffing smoke stacks (factories), poisonous plugs (rubbish dumps), farting animals and giant monocultures (agriculture).

The best time to plant a tree is 20 years ago - the second best time is now. Having said that there is such a thing as a tree in the wrong place. You do need to consider how big they will get long term - really long term. Most trees can live much longer than we can. We may as well plant them into places that they can stay forever. Sadly the Pin oak and Plane trees on Chaucer and Grasmere Street in Timaru were never really the right type of trees for that location. These days when we want to plant big trees in streetscapes we’ve got great gadgets and methods to make sure the roots stay out of trouble. Don’t let the Council tell you it’s too expensive. We need to LIVE! Trees are a fundamental part of our ability to live.

So next time you’re feeling grumpy about blocked gutters and drains - look up at those magical leaves and take deep breath of fresh air and call a maintenance crew to help you sort it out. Better yet, install gutters and pipes that are designed to cope with the conditions this planet provides us. After all, trees were here first, we’re living with them not them with us.