Why are the oldest and tallest trees all conifers?

[Glenn MacGrady]

Is this true? If fully or partially true, why do conifers live so much longer and grow so much bigger than (single stem) longleaf non-conifers?

I suppose I could ask AI. But we have foresters, botanists and other biologists here, and for ancient trees I'd rather ask ancient humans.

 

[recped]

Conifers are smarter?

 

[GeoBoy]

The term bristlecone pine covers three species of pine tree (family Pinaceae, genus Pinus, subsection Balfourianae). All three species are long-lived and highly resilient to harsh weather and bad soils. One of the three species, Pinus longaeva, is among the longest-lived life forms on Earth. The oldest of this species is more than 4,800 years old,<a href="https://en.wikipedia.org/wiki/Bristlecone_pine#cite_note-oldest-1"><span>[</span>1<span>]</span></a> making it the oldest known individual of any species. Many scientists are curious as to why this tree is able to live so long. In one study, they discovered that Pinus longaeva has higher levels of telomerase activity, which further slows or prevents the attrition rate of telomeres.<a href="https://en.wikipedia.org/wiki/Bristlecone_pine#cite_note-2"><span>[</span>2<span>]</span></a> This potentially contributes to the extended life of the bristlecone pine.
I visited these trees at Great Basin NP in Nevada.

 

[Glenn MacGrady]

Conifers are smarter?

Maybe. Or maybe it's diet. Tree experts report that conifers have never been seen eating, for example, Costco chicken.

 

[scoutergriz]

the largest is the California Redwood, though it's classification is challenged due to it actually being in the cypress family, not the true conifer family, a close second and true conifer is the BC or Douglas Fir which can easily hit 100m/330' in height, although there are reports of 120m+/400'white pines harvested on the Ottawa valley in the late 1800's

 

[ppine]

To try to answer your question, conifers have highly evolved vascular systems. What limits tree height is the Turgor pressure required to hold up a column of water in a tree to its height at the terminal leader. We can measure the suction in atmospheres, bars or lots of other ways. It may be that height growth and competition for light is what has caused conifers to evolve as trees with great height growth.

Longevity is even harder to evaluate. Old growth trees only live a long time because they have not been taken out by fire, drought windthrow, disease, insects or some other calamity. They are resilient, hardy, well adapted, drought tolerant. Conifers are sturdier.

They are more primitive types of plants are Monoecious with both male and female reproductive organs on the same tree. They are Gymnosperms. Importantly they mostly have decurrent growth form which is a single terminal leader and whorls of branches which encourages height growth.

 

[tketcham]

Why are the oldest and tallest trees all conifers?​

I assume that you mean individual trees because some of the oldest tree organisms are quaking aspen (Populus tremuloides) clones. But as GeoBoy posted, the oldest single trees are bristlecone pines. I think that the apical dominance of conifers may contribute to why they are generally taller than decidous/hardwood trees. And for coastal redwood (Sequoia sempervirens) trees, there is evidence that the fog intercepted in the crown is taken in by foliar shoots (shoot dimorphism) that absorb water for use in the upper crowns, thus allowing redwoods to acheive heights that might not be possible due to cohesion-tension and vapor pressure.

 

[NikonF5user]

Growth dynamics also play a big role here - conifers in general grow more slowly than do deciduous trees, meaning they take far more time to reach the maximum potential for their growing location. Also pine wood vascular tissue (composed solely of tracheids) is less dense, meaning there is less toppling potential due to weight being more focused down low on the tree, especially when combined with the fact that pines often have a smaller portion of the biomass in large branches (meaning even a greater portion of conifer biomass tends to be held within the trunk, thus even less toppling potential). Combine slower growth with biomass focused lower in the trunk, and you have the potential for a tree to live a VERY long time.

There is also one other factor - pines in general tend to grow where leafy trees struggle. Meaning they often do not face competition from faster-growing leafy flowering trees that would limit the lifespan of the pine...