4 ms·

Also pertinent to wind resistance is whether or not the tree is deciduous, the shape of the leaves' margin, the texture of bark and how they interact as a group

by chicob 8y ago

Also pertinent to wind resistance is whether or not the tree is deciduous, the shape of the leaves' margin, the texture of bark and how they interact as a group in forests. Another aspect that explains why the vascular explanation is not enough is the resistance of the trunk in supporting the wood's weight. Also important here is the roots' structure. When I imagine a situation where wind resistance is fundamental, I think of palm trees being subject to seasonal tropical storms, and these look nothing like the diagram in the article. Underwater, where vascularization and weight are not as important to many branching structures like corals or algae, there is still the problem of resistance against a moving fluid. But the branching/girth/length/angle rules seem to be different. So I'm still with team "branching optimized for sun/air exposure and constrained by vascularization, weight and root structure".

dsnuh 8y ago
Just a note - palm trees are part of the grass family, and have more in common with bamboo and turf grass than they do with trees. It doesn't surprise me that they would be different.
- chicob 8y ago
  Exactly. And here is the point: what exactly does 'tree' mean here? Palm trees, bamboo, corn, reeds and such are all of them quite different from the schema presented in the article. This schema seems to be some specific subset of large Eudicots, like magnolias, oaks, shrubs and such, or at any rate some paraphyletic family of plants. In taxonomical terms, Pinophyta are even more distant from the aforementioned plants, all of them Magnoliophyta. Pine trees, cypresses and other Pinophyta branch as well, but their branching does not fit the schema in the article. Why wasn't the hypothesis tested against the Pinophytae' specific (and quite common) kind of branching? Is surrounding fluid resistance only important for that arbitrary set of plants? If fluid resistance, ubiquitous in plant evolution, were of such an importance in explaining a difference between what is predicted by the vascular hypothesis and what is actually observed in branching trees, the same could be said for all trees that branch, and this theory should be able to do some predictions for other branching (and non-branching) plants. This hypothesis should have been tested for other structures right from the start, and not just for an idealized form of unwarranted generality. But don't get me wrong: I think that it's very good to have aerospace engineers putting forth this idea, and this article adds to our understanding of tree growth and evolution. I just find it incomplete.
  - posterboy 8y ago
    Most plants would be protected by trees, so trees kinda ... stand out.

by chicob 8y ago

dsnuh 8y ago

Just a note - palm trees are part of the grass family, and have more in common with bamboo and turf grass than they do with trees. It doesn't surprise me that they would be different.

chicob 8y ago
Exactly. And here is the point: what exactly does 'tree' mean here? Palm trees, bamboo, corn, reeds and such are all of them quite different from the schema presented in the article. This schema seems to be some specific subset of large Eudicots, like magnolias, oaks, shrubs and such, or at any rate some paraphyletic family of plants. In taxonomical terms, Pinophyta are even more distant from the aforementioned plants, all of them Magnoliophyta. Pine trees, cypresses and other Pinophyta branch as well, but their branching does not fit the schema in the article. Why wasn't the hypothesis tested against the Pinophytae' specific (and quite common) kind of branching? Is surrounding fluid resistance only important for that arbitrary set of plants? If fluid resistance, ubiquitous in plant evolution, were of such an importance in explaining a difference between what is predicted by the vascular hypothesis and what is actually observed in branching trees, the same could be said for all trees that branch, and this theory should be able to do some predictions for other branching (and non-branching) plants. This hypothesis should have been tested for other structures right from the start, and not just for an idealized form of unwarranted generality. But don't get me wrong: I think that it's very good to have aerospace engineers putting forth this idea, and this article adds to our understanding of tree growth and evolution. I just find it incomplete.
- posterboy 8y ago
  Most plants would be protected by trees, so trees kinda ... stand out.