(Arboricultural-styled) 'Fact of the Day'

[Kveldssanger]

Foreword: I have put this within the Training & Education sub-forum as ultimately I do not consider this to be better-placed anywhere else, in terms of appropriateness.

 

I'm creating this thread for two reasons: (1) there are so many wonderful snippets of information that exist, scattered across a consistently-growing pool of publications, or (2) because consciously looking for important information is a good way to supplement learning.

 

The facts, figures, or observations I cite will be fully referenced, and will be tree-related in some manner. There are no true bounds with what I cite - the citation may be to do with tree mechanics, woodland management, woodland conservation, or otherwise. I seek to make one post per day, assuming I am able to do so.

 

Hopefully those who read this thread will find some (or perhaps all) of the facts useful, and by all means feel free to start up discussion related to my posts (particularly if you have information to add - if you do provide further information, please look to reference wherever possible).

 

So without further hesitation, here are the first 101 facts linked below.....

 

 

Fact 1 – A history of coppice woodlands

 

Fact 2 – Branch failures in wind storms

 

Fact 3 – What is bark?

 

Fact 4 – A history of man trying to afforest the Black Country, UK

 

Fact 5 – Mycorrhizae-facilitated communication between individuals

 

Fact 6 – Root severance and tree stability

 

Fact 7 – Development cycle of wood-decay fungi

 

Fact 7.5 – A brief history of Ancient Woodland in the UK

 

Fact 8 – Coal deposits of the past

 

Fact 8.5 – Europe's lack of tree diversity

 

Fact 8.75 – The resource demand of trees

 

Fact 9 – Endo- and ecto-mycorrhizal fungi

 

Fact 10 – An overview of cladoptosis

 

Fact 11 – Trees can help with human recovery

 

Fact 11.5 – Aborting fruit to improve tree vigour

 

Fact 12 – Vigour and vitality

 

Fact 13 – Photosynthesis

 

Fact 14 – How residents perceive trees

 

Fact 15 – Bid cherry-mediated competition between two of its principal herbivores

 

Fact 16 – Coppicing ability and suckering

 

Fact 17 – Concrete and asphalt as mulch?

Fact 18 – Root penetration of sewer pipes

 

Fact 19 – So exactly how small are micro-organisms?

 

Fact 19.5 – Bat-shaped soil amoebae

 

Fact 20 – Arbuscular mycorrhizae benefits

 

Fact 21 – What do plants need to grow?

 

Fact 22 – Utility installations and root pruning issues

 

Fact 23 – Seedlings and susceptibility to pathogens

 

Fact 24 – Bumblebees self-medicating!

 

Fact 25 – Doesn't exist because I cannot count above 24.

 

Fact 26 – Apical dominance

 

Fact 27 – Fertilisation – is it good or bad?

 

Fact 28 – The Black Poplar

 

Fact 29 – Sporophore (fungal bracket) formation

 

Fact 30 – Trees to regulate temperature

 

Fact 31 – Honey fungus sporulation

 

Fact 32 – Saproxylic insects

 

Fact 33 – A video on photosynthesis

 

Fact 34 – The pale tussock moth

 

Fact 35 - Białowieża National Park, Poland

 

Fact 36 – Reproductive growth in plants

 

Fact 37 – How plants detect light and the birth of pigments

 

Fact 38 – A more detailed look at light and photosynthesis

 

Fact 39 – Adaptive growth in response to mechanical stimuli

 

Fact 40 – Gravitropism / geotropism

 

Fact 41 – Telepathic plants

 

Fact 42 – Vernalisation

 

Fact 43 – Phenotypic variation as a means of compartmentalisation

 

Fact 44 – Responses by plants to herbivory

 

Fact 45 – Monoecious and dioicous trees

 

Fact 46 – Insects and flowers

 

Fact 47 – Trees and crime rates

 

Fact 48 – Branch shedding in more detail

 

Fact 49 – Factors that influence cladoptosis

 

Fact 50 – Ground-level ozone and CO2 impacts upon trees

 

Fact 51 – Hawthorn progeny

 

Fact 52 – How to reference more than one sorbus species

 

Fact 53 – Variegated leaves

 

Fact 54 – The different roles of buds

 

Fact 55 – Soil bulk density

 

Fact 56 – Metasequoia glyptostroboides in the UK

 

Fact 57 – Resource allocation in fungi

 

Fact 58 – Air pollution and tree health

 

Fact 59 – Trees and flooding

 

Fact 60 – Honey fungus and its control

 

Fact 61 – Heteroblastic eucalypts

 

Fact 62 – Irrigating mature trees

 

Fact 63 – Climate and fungi

 

Fact 64 – Leaf retention in deciduous trees

 

Fact 65 – Growth ring width

 

Fact 66 – Nitrogen fixation in soils

 

Fact 67 – The decomposition subsystem

 

Fact 68 – An introduction to Inonotus hispidus

 

Fact 69 – The timing of pruning operations

 

Fact 70 – When to fertilise the soil

 

Fact 71 – Chlorophyll fluorescence

 

Fact 72 – Private woodland owners' attitudes to threats to tree health

 

Fact 73 – Some more information on cladoptosis

 

Fact 74 – Adverse impacts upon human health of tree pollen

 

Fact 75 – Fruit-ripening and seed dispersal strategies of trees in different climates

 

Fact 76 – Adventitious buds

 

Fact 77 – Aerial roots and what they are for

 

Fact 78 – How pathogens influence growth of plants

 

Fact 79 – Root grafting in the natural environment

 

Fact 80 – Phenotypes

 

Fact 81 – Wood weight loss and plant growth

 

Fact 82 – Factors affecting leaf conductivity

 

Fact 83 – Vascular properties of trees

 

Fact 84 – Mycorrhizal inoculation when transplanting trees

 

Fact 85 – What drives stem elongation?

 

Fact 86 – Xerophytic adaptations

 

Fact 87 – How trees influence landscape connectivity

 

Fact 88 – The changing demands of society

 

Fact 89 – The real risk of trees

 

Fact 90 – Move the target and not the tree

 

Fact 91 – Storm water accumulation and trees

 

Fact 92 – London's tree population

 

Fact 93 – The depth that roots will grow at

 

Fact 94 – Root crown excavation and the impacts the practice has upon trees

 

Fact 95 – The peer-to-peer tree community network facilitated by mycorrhizal fungi

 

Fact 96 – Soil pollution with heavy metals

 

Fact 97 – Allelopathy in walnut

 

Fact 98 – Chemical control of horse chestnut leaf miner

 

Fact 99 – Getting to the root of root growth

 

Fact 100 – Fungal colonisation strategies of heartwood rotters

 

Fact 101 – Scattered veteran trees in farmland as keystone habitats

 

 

 

 

09/08/15: Fact #1.

 

During the 18th and 19th centuries, coppice woodlands underwent an 'improvement' period, which involved either (1) selective removal of more undesirable species with artificial planting / propagation of more desirable species, and (2) conversion to high forest (perhaps even the former followed later by the latter).

 

In reference to point (1), whilst many coppice woodlands only saw such improvement come in the form of gap-filling with Fraxinus excelsior and other desirable species, composition of other woods dramatically changed. For example, in the South-east Lowlands, certain coppice woodlands saw the introduction of Castanea sativa, Fraxinus excelsior, Corylus avellana, and Alnus glutinosa, whilst simultaneously seeing the removal of Acer campestre and, in somewhat of a paradox, Fraxinus excelsior, where the overriding objective of coppice was to harvest Corylus avellana poles. In the Western Uplands, Quercus petraea, and to a lesser extent Quercus robur, were selectively planted with the intention of subsequent harvesting for the leather tanning process and for charcoal to be sold into the metal industry, whilst Corylus avellana was selectively removed.

 

In reference to point (2), the conversion of coppice to high forest was driven by local demands (or even general neglect). Where action was deliberate, Quercus spp. were principally planted, though Fagus sylvatica was also planted in abundance (notably in the Chilterns and the Cotswolds) as, after a period of undesirability (due to its poor coppicing ability), it could now flourish within the high forest, continuous cover-esque style management regimes. Ultimately however, Quercus spp. planting was more evenly-spread than Fagus sylvatica planting.

 

Source: Peterken, G. (2015) Woodland History in the British Isles – An Interaction of Environmental and Cultural Forces. In Kirby, K. & Watkins, C. (eds.) Europe's Changing Woods and Forests: From Wildwood to Managed Landscapes. UK: CABI.

Edited December 19, 2015 by David Humphries
List updated

[daltontrees]

Go for it! It will be nice to look in on Arbtalk and see something daily that is gratuitously informative. And about trees! Always a bonus on the perennially cosmopolitan Arbtalk.

[Kveldssanger]

10/08/15: Fact #2.

 

The majority of branch failures occur when winds exceed 50mp/h and during the period where foliage is present. Further factors will, of course, either increase or decrease the propensity of failure at and above such a threshold. During leafless periods of the year, wind gusts of between 50-75mp/h very rarely cause branch failure. Such research was undertaken between 1992-1999.

 

Source: Luley, C., Pleninger, A., & Sisinni, S. (2002) The effect of wind gusts on branch failures in the city of Rochester, New York, U.S. In Smiley, E. & Coder, K. (eds.). Tree Structure and Mechanics Conference Proceedings: How Trees Stand Up and Fall Down. USA: International Society of Arboriculture.

[sloth]

Nice thread...

[kevinjohnsonmbe]

10/08/15: Fact #2.

 

The majority of branch failures occur when winds exceed 50mp/h and during the period where foliage is present. Further factors will, of course, either increase or decrease the propensity of failure at and above such a threshold. During leafless periods of the year, wind gusts of between 50-75mp/h very rarely cause branch failure. Such research was undertaken between 1992-1999.

 

Source: Luley, C., Pleninger, A., & Sisinni, S. (2002) The effect of wind gusts on branch failures in the city of Rochester, New York, U.S. In Smiley, E. & Coder, K. (eds.). Tree Structure and Mechanics Conference Proceedings: How Trees Stand Up and Fall Down. USA: International Society of Arboriculture.

 

Like that factoid!

[armybloke]

This thread is going to be very useful...keep going.....

[Kveldssanger]

11/08/15. Fact #3.

 

The bark, or outer shell of a tree, usually comprises 10-15% of a tree's cellular structure. Made up of the outer bark (rhytidome) and inner bark (phloem), the former is the older, dead (and full of waxes and suberin) portion of cells and the latter the younger, living cells. With regards to the rhytidome, it's purpose is to protect against desiccation, heat, and damage, and normally forms as the tree ages. In certain species, such as Pseudotsuga spp. and Sequoia spp., the rhytidome is very thick - for sequoias in particular, the rhytidome may reach a thickness of up to 60cm (or 2ft).

 

Source: Dujesiefken, D. & Liese, W. (2015) The CODIT Principle: Implications for Best Practices. USA: International Society of Arboriculture.

[armybloke]

Which tree has the thinnest?

[Kveldssanger]

The book didn't say, though I'm going to guess something like Fagus sylvatica. Certainly species that exist in more moderate, less erratic climates wouldn't need such a thick outer bark.

 

I'm not sure why the book uses rhytidome as it's not a term that is used much any more, as far as I am aware.

[Kveldssanger]

12/08/15. Fact #4.

 

The Midland Reafforesting Association was created in 1903 with the intention of undertaking afforestation projects (amounting to 14,000 acres) across the Black Country, England. Whilst in principle such projects were met with support by the government and other organisations, less than 1% of the target was planted so by 1925 the project was terminated and the Midland Reafforesting Association dissolved.

 

Predominant drivers behind the failure of the project included the residents' acceptance of the industrialised and bleak landscapes as if they were the norm and status quo, the lack of necessary funding from bodies that verbally supported the efforts of the Midland Reafforesting Association (particularly as the subsoiling / ripping of poorer-quality sites being very expensive), 'technical difficulties' (species selection, poor site quality, etc), and the fact that one of the core motives for the afforestation project, that of such forest creation improving land value, was at the time not supported by crucial evidence in favour of such a claim.

 

Unfortunately, and somewhat ironically, only one-sixth of the derelict 14,000 acres remained by 1953. Most had been built on due to demand for infrastructural services and homes for the rising population of the UK. The remaining derelict land, which would amount to around 2,400 acres, did funnily enough regenerate naturally, gradually 'greening' the residual areas left behind after continued construction.

 

To top the whole thing off, The Black Country Urban Forestry Unit (BCUFU) that was formed in 1985 to continue the efforts of the project from 1903, which evolved into the National Urban Forestry Unit (NUFU) in 1995, also disbanded (prematurely) due to a lack of funding from central government. The project managed to plant 837 acres of woodland over six years with a £8.5m budget, before calling it a day.

 

Not all is lost in failure however, as the lessons drawn from the demise of such an ambitious project paved the way for research into species selection for plantations, management of plantations, and planting techniques.

 

Source: Webber, J. (2008) Greening the Black Country: The Work of the Midland Reafforesting Association in the Early Twentieth Century. Arboricultural Journal. 31 (1). p45-62.