Trees

[petrushka.googol]

What determines the theoretical maximum height of a tree ?

 

Some trees are tall but there appears to be a cap on this.

 

How does mass distribution and gravity play a role in this ?

 

Please advise.

[Acme]

What determines the theoretical maximum height of a tree ?

Ultimately, genetics controls wood strength and growth habit.

 

Some trees are tall but there appears to be a cap on this.

No doubt there are limits, though I've never seen a theoretical limit given. The tallest known standing tree today is Type, Coast Redwood (Sequoia sempervirens): Height, 115.72 m (379.65 ft): Named, Hyperion: Location, Redwood National Park, California, United States [@ Wiki]

 

How does mass distribution and gravity play a role in this ?

Please advise.

The arrangement of leaves and branches on trees (actually all plants) follows a patterning of dual Fibonacci numbers which varies by species; this patterning is called phylotaxis. These patterns not only distribute mass for stability, but also the patterning distributes leaves for optimal exposure to light. The patterning is an ideal however and can be disrupted by many physical factors such as neighboring trees, damage from wind, lightning, insects, etcetera. All else being equal, the tallest trees depend on a little luck.

[Basic Biology]

What determines maximum tree height isn't known for sure but I believe the most popular hypothesis for maximum height is the hydraulic limitation hypothesis proposed by Ryan et al. in 1997.

 

The hypothesis basically proposes that height is limited because resistance for water transport up the tree increases with height and gravity increases with height. Leaves require a certain amount of water to maintain functioning properly. If water supply is too low then leaves are unable to photosynthesize enough to produce excess energy for further growth in height.

 

I think that's pretty much the gist of it.

[Harold Squared]

Gravitational force does not "increase with height" you have it backward. One weighs less on a mountaintop than in an adjacent valley. Try it sometime, all you need is a sense of adventure and a suitable scale. For similar reasons one weighs more at sea level at the poles rather that at sea level at the equator, both due to being farther from the planet's gravitational center and due to the centrifugal effect of planetary rotation.

 

For completely different reasons plants are stunted or absent in the polar latitudes and taller in the tropics.

Edited April 6, 2015 by Harold Squared