I just came across this picture on Houzz:
Is it to straighten the tree ?
I think that this is funny in a sad way. That little tree with no leaves on it yet doesn't need any help growing straight. It doesn't need any saving from a stiff wind. In fact it will be a few years before it gets enough leaves that a stiff wind would be able to catch to do any harm. By staking so thoroughly when that 'straight' jacket is finally taken off, the tree will have leaves and a weak trunk and it will be vulnerable to wind damage or snow coming off the roof. This is akin to a cast on your arm or leg. Remember when the cast came off after wearing for a few months? The atrophy of muscle and bone loss?
Trees are designed so that when they are small and forming the wind causes movement of that trunk which in turn causes the trunk to get thicker and the supporting roots larger/deeper. Somewhere I've got a great picture of two different plant beds with the same trees side by side. One owner used stakes the other, my client of course, had none. The difference was phenomenal. The unstaked trees looked 5 years older with 8" diameter trunks versus 3" diameter of the staked trees. Same trees, same nursery, same caliper when purchased. Seriously movement is important, no critical, for the health and strength of a tree.
At least these stakes won't get forgotten they are so ugly...so is that bark mulch but that is another story. I only stake trees if they are a mature tree that has fallen over or if they were a newly planted bare root tree. Otherwise, I never stake trees. I also go through parking lots with a blade and cut the ties off trees. I know, I am bad but the trees I remove from stakes and girdling are always the biggest and healthiest. City projects have specifications that always need updating. Cut and paste specs that always include staking each and every tree or twig cause others to think this practice is somehow necessary. Can you imagine this tree ever being blown over? In a few years when those things are taken off when it has a decent canopy, you just might. And then they'll stake it again leave the stakes and ties even longer 'just to make sure' and when taken off, even more liable to be blown over. Plants grow to get the most light. Actually bending to optimize exposure. You've seen flowers do it in slow motion, well, young trees are doing the same only imperceptible to our eyes. This helps to build stronger trunks and get energy allocated to building thicker trunks...and roots. Without being able to move the energy goes into the canopy, lots more leaves, weak trunk, weak root system equals a good chance of being blown over. Just like that atrophied arm when the cast comes off. That arm is fragile and one has to be very careful so as not to break it again while it is trying to thicken the bone and strengthen the muscles. If it ain't broke...don't 'fix' it.
Oh, and those trees in the nursery that are Balled and Burlapped and planted in sawdust? No root growth, plenty of canopy, definitely a clay soil root ball, copper sulfate coating the burlap...the greenish color...to inhibit root growth into the sawdust. And they endure entire seasons waiting to be purchased. With few exceptions, these trees grow straight and aren't blown over. The are never staked, either. I've seen entire swaths of poplars blown over by major wind but their problem was being planted too close to one another, sharing resources, protected from light winds thus making them weak...then like dominoes they all fall down.
It keeps the tree growing upright.
Note: the tree is very near the house and the roof, so wind, snow and shadows are much more directional than in conventional cases.
I think it helps also to simulate much more the tree space (or now it will seem empty) and help cars not to crash on it. This last point is not really relevant in this case, but it is easier to to always the same structure. Installing one or three poles it take nearly the same time and costs.
well well well... I just got my answer today. It rained cats and dogs and I have a Shaina Japanese Maple. This guy is 3ft tall and with a wide canopy. It got loaded with tons of water and it simply bent down under the weight of the water. The trunk is a little curved at the contact with the soil (it grew like this) an that contributed to the issue. I now understand why something like the above support is needed