Get Bent: Why Trees Have Curves in Them

A wicked curve molds this tree along the Thames River

Have you ever walked by a tree and wondered to yourself, “Wow, what an unusual tree! I wonder how it got like that?”

There are a few interesting trees on the bike paths along the Thames River in London, Ontario. Some are covered in warty bumps that line their trunks. Others have long bending limbs which swoop at crazy angles. They are odd enough to make you wonder if that is how they are meant to grow. Or if not, what caused them to morph into the head-turning tree they are now?

Trail trees were created by First Nations people to help mark trails, medicinal plants or other significant sites

In the case of bent trees, there are other trees around the world which exhibit abnormal patterns in growth. In North America, First Nations people used trees to mark significant areas, like trails, river crossings, places to find medicinal plants, and holy grounds where council meetings met. Saplings were chosen and bent to the ground for a period of time. They were held in place with rocks, vines or rawhide until such time as they stayed in place, before being released. The purpose of this was to mark the spot and in a time before GPS, they were effective signposts.

Windswept Pine Tree @ Killbear Provincial Park, Ontario by Brian Krouskie

The long loops in the trees in Springbank Park aren’t as angular as trail trees though, so what else might have caused their bends? Oftentimes trees are affected by the elements. In places where strong winds exist, trees lean away from the breeze. With a constant buffet of wind from one direction, trees get permanently affected, resulting in branches leaning to one side. Would there have been enough wind along the Thames to warp some trees, while others grow straight to the sky?

No one knows what caused these pine trees in Poland to get their unusual curves; was it aliens?

Sometimes a tree’s growth pattern is permanently affected by a storm. A hurricane, tornado, ice storm or even heavy snow might push a tree over or break branches, but not necessarily kill the tree. As the tree recovers, it accommodates its new growth from the point of damage, often bending at the affected area as it begins to grow again.

But sometimes a tree grows a little crooked not because of people or natural disasters, but because it is searching for the best place to grow. It’s called phototropism and it happens when a tree grows towards the light. You might notice it in house plants which sit in a bright window and never get turned. Growth is focused towards the light. If the plant is left in that exposure for a period of time, it grows accordingly. Since light is essential to photosynthesis—which is how a plant gets its nutrients—it makes sense; get as close to a food source as possible. And since trees can’t be plucked from the ground and turned, they do the next best thing and adjust their growth towards their light source.

Do you know of any bent trees? Any guesses on how they got that way?