(Arboricultural-styled) 'Fact of the Day'

[Kveldssanger]

6/10/15. Fact #53.

 

Variegated leaves are attractive from an aesthetic standpoint, though the reduced chlorophyll content in the leaf structure's creamy-white parts means that such variegated cultivars lack the vigour of their non-variegated conterparts.

 

In the natural world, this would mean that any sporadically-occurring specimens that do have variegated leaves are quickly out-competed by non-variegated specimens. This is why variegated specimens in the wild are incredibly rare. If one is found, it must be vegetatively reproduced via budding, grafting, or cutting - sexual reprpduction is not possible. Even then, the genetic 'instability' that caused the mutation may 'revert', in turn causing variegated specimens to change back to non-variegated forms later in life.

 

In botanic gardens and general home-owner gardens therefore, variegated individuals should be planted where there is little light competition. Reduced photosynthesis will also mean, as stated, they have lesser vigour, which will cause slower growth and, I also suspect, cause higher disease susceptibility if the niche that they occupy changes in any manner (or is adverse to begin with).

 

Source: Watson, B. (2006) Trees - Their Use, Management, Cultivation, and Biology. India: Crowood Press.

Edited October 6, 2015 by Kveldssanger

[sloth]

An interesting one. I've often wondered in the past if I see more Kretzchmaria (in particular) and Meripilus on copper beech than standard, or if I'm just imagining it! Might make for an interesting study...

[daltontrees]

6/10/15. Fact #52.

 

An earth-shattering fact for today. Didn't realise this myself...!

 

The plural of Sorbus is (at least for the English language) Sorbi. I am unsure whether in has any basis in general nomenclature, however.

 

Source: Watson, B. (2006) Trees - Their Use, Management, Cltivation, and Biology. India: Crowood Press.

 

This is just following the declension of nouns in latin, not just reflecting that it is plural but that it is in what is called the second declension group of nouns and is feminine. Why? Because the romans had a name for the service-berry tree - Sorbus.

 

The plurals of other trees known to the romans are (officially)

Fagi, Fraxini, Populi, Quercus, Tiliae, Coryli, Ulmi, Castaneae, Salicis, Alni, Betulae, Aceris, Platani.

 

I don't know what the convention is for trees not of direct latin origin. For example a tree that could not have been known to even Rome's expansive empire - Sequoia. The reason for the choice of name by Endlicher in the mid 1800s is not known and it is not even derived from latin adjective, it is merely latinised i.e. made to look latin but how it is to be made to behave like a latin word when made plural is not known to me except that by default it must be deemed a first declension group noun. Hence a good guess would be Sequoiae.

 

It's all a bit purist, and I think that if a group of trees of the same genus were being described the use of the common name would be most appropriate. But what if there is a group of Rowan, Whitebeams and Service Trees? The smart-ass would no doubt relish the unassailable once-in-a-lifetime use of the word 'Sorbi', because the alternative would be to say 'look, a group of trees all of the genus 'Sorbus'. But the romans would undoubtedly have said "Ecce, sorbi!" and their fellow romans would know exactly what they meant.

 

I think it is probably one speculation too many as to whether Sorbi should be italicised or not. I think it probably should but I am not in Italy, never mind Rome and I reserve the right not to do as the Romans did.

[Haironyourchest]

Kveldssanger, I just started reading your thread, way back fact 3 or 4 about the failed attempt to reforest the Black Country and how some of the derelict land greened up naturally. Im fascinated by the regenerative power of nature, around here, when they harvest spruce and leave a no-mans land of sticks, mud and churned up bog and clay, it takes about ten years to completely regenerate a forrest of sallies, birch mountain ash, holly, rhododendron, just from windblown seeds.

[Kveldssanger]

Kveldssanger, I just started reading your thread, way back fact 3 or 4 about the failed attempt to reforest the Black Country and how some of the derelict land greened up naturally. Im fascinated by the regenerative power of nature, around here, when they harvest spruce and leave a no-mans land of sticks, mud and churned up bog and clay, it takes about ten years to completely regenerate a forrest of sallies, birch mountain ash, holly, rhododendron, just from windblown seeds.

 

Aye. Natural succession by just leaving a site alone is the best way to facilitate woodland regeneration. You'll find the most optimal genetic provenance, likely much better diversity over time, and better complexity. It just takes a long time.

 

 

An interesting one. I've often wondered in the past if I see more Kretzchmaria (in particular) and Meripilus on copper beech than standard, or if I'm just imagining it! Might make for an interesting study...

 

It would make a good study. Perhaps someone will try it, if it hasn't already been tried?

 

 

This is just... the Romans did.

 

Fascinating post.

[Kveldssanger]

8/10/15. Fact #54.

 

Buds are able to produce exclusively vegetative growth, exclusively floral growth, or both / either; as in, a bud has the potential to form both vegetative and floral growth or one or the other, whereas other buds can only form one or the other by default and are thus 'predetermined' to be either a flower or form an extended shoot.

 

Such 'role allocation' of buds varies between species, though the buds of Aesculus hippocastanum and Prunus avium are just two examples that aid with the illustration of the point being made.

 

A. hippocastanum, for instance, will always have its terminal bud develop into a flower raceme - this means specimens will be multi-branched (sympodial) - though obviously not when young, as the tree will not begin to flower until a specific age (flowering when very young from the dominant bud would reduce its competitive ability in searching for light). P. avium, alternatively, will always have its apical bud form shoot extension growth and instead flower on lateral buds, thereby not terminating the apical growth of the specimen as readily. Of course, such species and specimens are not monopidal, though do have more of an upright habit on average.

 

Clearly, other factors will play a role on the exact form that trees adopt (phototropism, geotropism, other tropisms, natural or mechanical damage, hormones [auxin, ethylene, gibberelic acids], and so on), though this underlying principle is one (arguably main) driver in structural tree physiology.

 

Source: Watson, B. (2006) Trees - Their Use, Management, Cultivation, and Biology. India: Crowood Press.

Edited October 8, 2015 by Kveldssanger

[Kveldssanger]

Ordered a few books (one by T. T. Kozlowski on flooding, and another on air pollution). They're both from the 70s, though look great from overviews. Will post some facts once they come through.

[Kveldssanger]

9/10/15. Fact #55.

 

Soil bulk density is, to some degree and in combination with other soil characteristics, reflective of the mechanical resistance roots meet in the soil. At higher bulk densities, root growth can be restricted as the forces exerted by the roots as they push through the soil cannot 'overcome' the resistant forces of the compacted soil. Further to this, increased bulk density reduces soil porosity and therefore offers less viable space for roots to grow within (given roots grow most often within aerated pockets of the soil structure). By-and-large, root growth is optimal at 1.2g/cm³ and limited seriously when bulk densities exceed 1.6 g/cm³. Road foundations in Copenhagen, Denmark are typically compacted to bulk densities exceeding 2g/cm³ however, which indicates - as a proxy - the extent of the problem for urban trees on a wider scale, in particular.

 

Sources:

 

Bassett, I., Simcock, R., & Mitchell, N. (2005) Consequences of soil compaction for seedling establishment: Implications for natural regeneration and restoration. Austral Ecology. 30 (8). p827-833.

 

Buhler, O., Kristoffersen, P., & Larsen, S. (2007) Growth of street trees in Copenhagen with emphasis on the effect of different establishment concepts. Arboriculture & Urban Forestry. 33 (5). p330-337.

[Kveldssanger]

9/10/15. Fact #56.

 

Seed from the Metasequoia glyptostroboides was not introduced to the UK until 1948, following discovery in 1946 in China. Therefore, no specimen in the UK can have existed before 1948. This makes, potentially, the oldest specimen 67-68 years old.

 

Source: Watson, B. (2006) Trees - Their Use, Management, Cultivation, and Biology. India: Crowood Press.

[tree-fancier123]

one place I work used to be owned by a botanist who planted one of those not long after the seeds became available, probably about 20" dbh now, nice tree, only thing is getting ivy on.

What do you reckon about ivy on nice specimen trees - if the money was there would you offer to cut it off, at least around the trunk in a band and let the top fall off?