All the tallest trees are evergreen: Sequoia sempervirens: 115m Pseudotsuga menziesii: 99m Eucalyptus regnans: 97m Picea sitchensis: 96m Sequoiadendron giganteum: 95m Presumably because the equable conditions that allow for really tall growth also allow for easy all-year leaf retention. The tallest deciduous tree I can think of is Larix occidentalis, with the tallest currently known being 58.5m tall (Gymnosperm Database: http://www.conifers.org/pi/la/occidentalis.htm ), and reported (unverified!) to 65m or even 80m in the past. Interestingly, like most of the tallest evergreen trees, a conifer. Can anyone think of any other taller deciduous tree? And what is the tallest deciduous Angiosperm tree? Tallest I can find info for is Liriodendron tulipifera at 54m (Eastern Native Tree Society).
Hi Michael, There is good evidence for very tall specimens of Eucalyptus regnans from mainland Australia with several specimens close to or well exceeding 100m. The wikipedia page for the species is a good starting point. As with many records, there is controversy surrounding some of the measurements. I have seen published some pictures of awesome specimens...but where I cannot recall. Your point about most tall species being conifers/evergreen is interesting...must have a think about this ! Ciao BrianO
Michael, I may have a candidate for the tallest deciduous angiosperm for you: Koompassia excelsa a member of the Fabaceae found in SE Asian rain forest. Some records at 85 and 88m. It looks like an evergreen, but on the web I found two brief mentions of deciduous behaviour - losing all its leaves in the dry season. What do you think? Ciao BrianO
Thanks! I'll look up the Koompassia. I'm very dubious about the old Eucalyptus regnans claims, and ditto for old claims about Pseudotsuga menziesii of up to 120m, etc. There's an awful lot of exaggeration in old records, and very few (if any) can be considered reliable.
Micheal, also try checking out Cedrela odorata (Cedro) and the trees of genus Ceiba, particularly Ceiba pentadra (Kapok) which can both push 80+ meters when they're mature. As far as I can recall, they are deciduous in their blooming phases. We have a Kapok deep in the Orellana province that is recorded at 95 meters. Cedro is a South American rainforest native, and Ceibas are pan-tropical. If I could recall anything other than the kichua common names (useless for your purposes) for some of the other trees I visited last weekend, I'd have more candidates for you; I was in a stand of virgin transitional forest and most of the trees were well over 75 meters tall. Of course, since you're pushing for deciduous trees, I can't include the giant Chonta palms, which were often taller than the surrounding canopy trees.
I wonder if it is several conditions. For example, wind breaks trees, but redwoods are at the coast. So are Douglas fir. Moisture is a nice bonus, but Ponderosa and Sugar Pine are still rather tall, and grow in some dry zones. So far, I have not read too much about the connection between height and resistance to decay, but it's related. A general single stem form compared to multiple stems seems related. Like a Yew with multiple stems is evergreen, but stays low and broad. In one way, you would think that deciduous would be a bonus for getting tall, since winter coastal winds would not have the foliage to push on with force.
I´d also add something to Vaden´s point, that the really tall trees tend to have extremely profound root systems. The only exception I can see to this are some of the shallow-rooted giants in tropical rainforests, which are easily toppled by a single strong storm. Wind doesn´t necessarily break trees, though - it can also work to strengthen them, and I wonder if this is´nt the cause of the magnificent resistance of redwoods. It may, though, be something unique to gymnopserms. Speaking from a country with next to no native conifers, I can say that our coastal areas are full of stunted trees from the constant wind. I think decay resistance has more to do with the heartwood density than with the actual height of the tree, but this said, the trees here that are strangled by Matapalo vines tend to rot once the parasite has cut off their supply of nutrients, but not before. Some of our really tall trees never fall down or seem to decay after they pass on - the Kapok being fair example of this. I´d venture to say that among the hardwoods, the more dense tree is likely to be the taller one, even though it may grow much more slowly. A comparison of Balsas and Kapoks is useful here, as the first lives only 20 years but gets quite tall, while an upper age range for the latter has not yet been established. Kapok wood is extremely dense.
There is a publication by George Koch about the maximum size of trees from a few years ago. I know it and some news stories based on it are available on the web. He climbed the tallest redwoods and made physiological and morphological measurements. As I remember he calculated a theoretical maximum height of about 130m. The key determinant was water supply to the top of the tree. I think that this might relate to why Michael's tallest tree list are all evergreens - it might be difficult to restart active water supply to the top of the tree after loss of all the leaves ? Brian's thought for the day. Ciao
Thanks, all! I checked out Koompassia excelsa; couldn't find any definitive statement on leaf persistence, but did find a couple of photos showing largely bare crowns. It's obvious though that the largest deciduous trees are dry-season deciduous, rather than cold-season deciduous. Interesting, considering that the two genera are closely related. Low density wood is the norm in most Malvaceae-Bombacoideae, Ceiba being unusual there. Probably a valid point, good thinking! Certainly with the tallest Sequoia sempervirens, "drought" conditions apply all the time, because of the difficulty of getting water 115m off the ground; the tops often get dieback after dry spells and regrow again during longer wet periods.
Certainly not nowadays, but prior to 1920 (before the chestnut blight killed them all)the largest deciduous tree has to have been the American Chestnut. Some specimens according to old timers and photos approached 180 feet and 15 feet in diameter, and not only was it the largest tree but also the most numerous in the eastern forest. Most estimates say 1 out of every 4 hardwood trees in the eastern forest was chestnut, and in the Appalachians it was more like 1 in 2. http://www.esf.edu/chestnut/background.htm
Prof. Sillett & Dr. Van Pelt did a presentation in Eugene, Oregon, last March. After a bunch of questions from the audience about carbon, I edged in a question about the dead tops in some north redwood groves, and whether they had a chance to core sample or study those to see if they are related. Prof. Sillett mentioned that many are associated with an exceptionally dry year or season in the mid 70's. : - )
Behavior is what it does every year, not in some years. Albino redwoods can lose leaves on the coldest years, but that does not make some redwoods deciduous. ...
Hi, maybe I need to clarify. By "in the dry season" I meant in the dry season which occurs each year. See for example this account: http://www.rainforestjournal.com/the-tualang-tree-or-koompassia-excelsa/ it also discusses briefly the possible reason for this deciduous behaviour in a largely evergreen forest. ciao Brian
