(Arboricultural-styled) 'Fact of the Day'

[daltontrees]

...yeah, that one turned out to be an essay in itself.

 

Good one, have the rest of the night off!

[Kveldssanger]

Watching a few videos by David Lonsdale for that very purpose.

[Steve Bullman]

...yeah, that one turned out to be an essay in itself.

 

Good read, thanks for taking the time. Its appreciated

[Kveldssanger]

You're welcome. Was a nice one to write about, actually. Will sort out an 'index' for the second lot of 50 soon, so there are links to them all.

[Kveldssanger]

17/12/15. Fact #101.

 

Scattered hedgerow trees out across the landscape can be regarded as keystone habitats for biodiversity, where traditionally keystone habitats would have been located within woodlands (incl. wood pastures) and forests. This is crucial, as these scattered keystone trees act as 'go-betweens', enabling species to 'hop' between larger wooded sites. In essence, habitat connectivity increases.

 

The authors state that the reason this phenomena has emerged for various reasons, and they use three examples:

 

1. The rove beetle Batrisodes adnexus (a Red Data Book species listed as 'endangered'), within the UK, was historically found only within medieval forests (Windsor and Epping, most notably), though has recently been found within the heartwood of a single mature Fraxinus excelsior in a farmland hedgerow boundary in Leicestershire, alongside many other saproxylic invertebrates. Without this hedgerow, the species would remain isolated to woodlands only.

 

2. Dorcatoma serra, a saproxylic beetle, which relies on Pseudoinonotus dryadeus upon Quercus spp. for its habitat, has usually been found only within old parkland areas but has now also been found within farmland hedgerow boundaries. It is suspected that this may be because these scattered old oak pollards are the remnants of what was once the Forest of Essex (located throughout large swathes of the county).

 

3. Upon Crataegus spp., the hawthorn jewel beetle Agrilus sinuatus can now be found throughout farmland hedgerow boundaries that contain mature hawthorns. Originally found only within woodland fringes and wood pasture sites where hawthorns were allowed to reach maturity un-managed, the abandonment of traditional hedge-laying techniques has lead to many field hedgerow boundaries growing into maturity and attaining decent sizes as well. This dramatically increases the viable habitat of the jewel beetle, and the scattered hedgerow hawthorns act as 'connecting' trees (because the beetle is unable to 'jump' great distances without 'stopping off' along the way) linking different woodland fringes and wood pastures.

 

Source: Butler, J., Green, T., & Alexander, K. (2012) Collections of ancient trees: hotspotting biodiversity, heritage and landscape value. In Rotherham, I., Handley, C., Agnoletti, M., & Samojlik, T. (eds.) Trees Beyond the Wood: an exploration of concepts of woods, forests and trees. UK: Wildtrack Publishing.

[Kveldssanger]

Hit 20k views this evening. Onwards and upwards.

 

Should get the new archive of facts done over the latter part of the weekend.

[Kveldssanger]

Ok here are the first 101 facts linked below. Can Steve or David edit the first page to just link to this post, and take out the list of current facts within the first page. Thanks.

 

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

[Kveldssanger]

18/12/15. Fact #102.

 

The necessity of soil mycorrhizae with regards to tree presence and health is become ever more clear, as research pursues further understanding of the tree-mycorrhiza relationship. Logically, one would anticipate for mycorrhizae to facilitate primary (we are not discussing secondary) succession of woodland, given the known importance of their presence, though research must still be undertaken as a means of quantifying and understanding such importance.

 

In this post, we therefore look at a study undertaken on a volcanic desert on Mt. Fuji, Japan, which seeks to ascertain exactly how mycorrhizal fungi enable primary woodland succession.

 

We must first set the scene. Mt. Fuji is a barren landscape, void of life on large expanses of its surface, and it has been this way since it erupted in 1707 and deposited 10m (in depth) of scoria upon its surface. Since then, plant life has slowly returned (it is now at 5% of total area), though most of the area is non-mycorrhizal and the soil is lacking in 'spore banks'. Within this desert, small patches (around 1% of the total land area) of ectomycorrhizal (ECM) habitat can be found existing within regions host to pioneering Salix spp. shrubs, as well as (though only for 0.003% of the area) Betula ermanii and Larix kaempferi. Such a site therefore provides for a wonderful opportunity to explore how ECM habitats develop and how they enable for the primary succession of plant species, particularly as Mt. Fuji resides within a forest landscape consisting of Quercus, Fagus, Carpinus, and Abies species. In time, these trees will succeed back onto the volcano, and it is expected that ECM will play a major role in this.

 

Within the 1% of land covered by dwarf willows, ECM sporocarps were found under all established willow shrubs (thought to have been propagated by wind, as willow can remain non-mycorrhizal by stalling growth), and these ECM exhibit a clear succession pattern. When dwarf willows first colonise an area, pioneer ECM can be seen to move in (Laccaria laccata, Laccaria amethystina, and Inocybe lacera). As these willows begin to establish some additional pioneer ECM species succeed into the area (Scleroderma bovista and Laccaria murina), though establish more on the periphery of the dwarf willow vegetation islands. Hebeloma, Cortinarius, Russala, and Tomentella species are found only within the larger and more established willow islands where soil organic matter has accumulated, and are considered late colonisers. Of all the aforementioned species, genets of particular species typically had smaller sizes whilst others occupied larger soil areas. For instance, Laccaria spp. principally achieved sizes of less than 1m, whilst Scleroderma bovista was found at sizes of up to 4m (though one was 18.4m in size).

 

With regards to the succession of plants into the vegetation islands, the research found that willow seedlings only could be found in the immediate areas surrounding the vegetation islands, where ECM had colonised the soil. Larger willow genets grew only within the centre of the vegetation islands where ECM were more abundant and diverse, whilst smaller genets colonised the periphery. Over time, we can begin to understand how this could extrapolate out into a bigger area.

 

The arrival of Betula ermanii and Larix kaempferi will follow willow establishment (this expalins why only 0.003% of the land area is colonised by these two species - 26 larch and 39 birch saplings were present at the time of study), and the species will use (some of) the same ECM species as the existing willow species use as a means for effective growth and survival. Their succession marks the onset of a forest ecosystem, which is a critical step in the transitional process between a barren environment and a wooded one.

 

In time, these two tree species will faciliate in the succession of further ECM species and this will, in turn, further aid with habitat provisional for other plant and tree species (that exist in the nearby forests), as will the gradual build-up of organic matter in the soil improve soil conditions enough to support more variable and expansive life - assuming the volcano doesn't erupt and reset the process.

 

I don't want to drone on here, as the chapter is very long, though hopefully this gives a brief insight into the primary succession of trees onto a largely barren and inhospitable volcanic landscape.

 

Source: Nara. K. (2015) The role of ectomycorrhizal networks in seedling establishment and primary succession. In Horton, T. (ed.) Mycorrhizal Networks. The Netherlands: Springer.

Edited December 18, 2015 by Kveldssanger

[Kveldssanger]

19/12/15. Fact #103.

 

This post is in keeping with the ectomycorrhizal theme and the capturing of information from a different chapter of the same book as used for the last source.

 

Mycelium growing away from the root substrate (so out within the soil) of ecomycorrhizal fungal species (EMF) is now being seen as a major player in carbon cycling (and may contribute up to 70% of total carbon sequestered in soil organic matter), because these extramatrical mycelial growths (EMM) require carbon in order to not only lay down new growth but to metabolise uptaken nutrients. It is therefore suggested that future soil carbon models should allocate for EMM growths and their effects.

 

The carbon used by EMF is provided by their host trees - this suggests that higher rates of photosynthesis may improve carbon allcoation to EMF and thus to EMM production. In fact, a study by Korkama et al. (2007) on spruce clones concluded that EMM production was greater when the host tree was fast-growing. Another study (Ekblad et al., 2013) undertaken on a larger scale within Norway spruce forests concluded similarly, and demonstrated that EMM growth was positively correlated to host tree productivity.

 

EMM growth rates within woodlands also correlate positively with woodland canopy structure. During canopy closure, when trees require the most nutrients so to pursue light (phototropism) and are reaching maturity, the EMM growth rate peaks (given the higher carbon provisions). Usually, this will occur between 25-40 years after the woodland first begun to develop.

 

Growth of EMM will also vary between species, as different EMF species will have different carbon demands. Therefore, if the host tree is under stress, perhaps due to herbivory or other reason, EMM growth may suffer. This was found to be the case with EMF species in symbiosis with pinyon pines. Where the host pines were being predated upon by scale insects, EMM growths were poorer - particularly in EMF species that are more carbon-demanding.

 

Sources:

 

Ekblad, A., Wallander, H., Godbold, D., Cruz, C., Johnson, D., Baldrian, P., Björk, R., Epron, D., Kieliszewska-Rokicka, B., Kjøller, R., & Kraigher, H. (2013) The production and turnover of extramatrical mycelium of ectomycorrhizal fungi in forest soils: role in carbon cycling. Plant and Soil. 366 (1-2). p1-27.

 

Korkama, T., Fritze, H., Pakkanen, A. and Pennanen, T. (2007) Interactions between extraradical ectomycorrhizal mycelia, microbes associated with the mycelia and growth rate of Norway spruce (Picea abies) clones. New Phytologist. 173 (4). p798-807.

 

Wallander, H. & Ekblad, A. (2015) The importance of ectomycorrhizal networks for nutrient retention and carbon sequestration in forest ecosystems. In Horton, T. (ed.) Mycorrhizal Networks. The Netherlands: Springer.

[Kveldssanger]

20/12/15. Fact #104.

 

Drawing attention back to fact 2 about branch failures in wind storms, I am following up with root failures in wind storms.

 

Interestingly, though perhaps expectedly, similar wind speeds are required to initiate windthrow as a result of the failure of roots, during a survey on 113 trees following Hurricane Fran in 1996 (74 of whcih were windthrown). When wind speeds exceed 50-60mp/h, roots even with only minor defects have a significantly higher chance of failing. Where defects are more severe, it will require a lower wind speed to induce failure, or even perhaps gravity in itself will induce the failure.

 

The study did also highlight that where high winds follow heavy periods of rainfall, the risk of windthrow increases. Risk increases yet further if the tree has a full foliage crown and the soil drains poorly in the locality to the tree's rooting environment.

 

Source: Smiley, E., Martin, T., & Fraedrich, B. (1998) Tree root failures. In. Neely, D. & Watson, G. (eds.) The Landscape Below Ground II. USA: International Society of Arboriculture.