(Arboricultural-styled) 'Fact of the Day'

[Kveldssanger]

17/09/15. Fact #34.

 

Bit of a different one today as well - a photo and a description.

 

So I was out picking some of the blueberries and apples from the garden, and something caught my eye in the twilight...

 

(Here are all the images in HD (not shrunk to fit here - they're great photos, if I may say so) - Calliteara pudibunda (Pale Tussock) - Album on Imgur)

 

 

...a pale tussock (Calliteara pudibunda) caterpillar!

 

So I thought I'd share a bit of info on the species...

 

Turns out they are "fairly common" across England and Wales in terms of distribution and abundance (they seem to have limited spread around the Midlands and from there hardly proceed further north), and the female form is larger than the male at the moth stage - the moth can be identified by the very furry legs that protrude outwards in front of the main body.

 

The species is associated with many small deciduous trees and shrubs (this one I found on a Malus sp.), and was in fact a pest of hop (Humulus lupulus) when it was once grown frequently. I bet beer lovers were furious...

 

...and don't touch them, as (like many caterpillars) they induce undesirable reactions. Coming into contact with the poisonous hairs or spines may cause skin rashes - or even a hypersensitivity reaction.

 

Sources:

 

An overview of the moth and its habitat.

 

Health issues associate with skin-to-caterpillar contact.

Distribution map of the species.

Edited September 17, 2015 by Kveldssanger

[Kveldssanger]

Will look to get a fact up tomorrow from one of my books that has a chapter on woodland management and conservation in Białowieża National Park. It's the only (?) forest within Europe that has never been extensively managed, if I recall correctly. It is used as a reference point for 'what could have been' if other forests (and associated ecosystems) were left to manage themselves.

[Eddy_t]

17/09/15. Fact #34.

 

Bit of a different one today as well - a photo and a description.

 

So I was out picking some of the blueberries and apples from the garden, and something caught my eye in the twilight...

 

(Here are all the images in HD (not shrunk to fit here - they're great photos, if I may say so) - Calliteara pudibunda (Pale Tussock) - Album on Imgur)

 

 

...a pale tussock (Calliteara pudibunda) caterpillar!

 

So I thought I'd share a bit of info on the species...

 

Turns out they are "fairly common" across England and Wales in terms of distribution and abundance (they seem to have limited spread around the Midlands and from there hardly proceed further north), and the female form is larger than the male at the moth stage - the moth can be identified by the very furry legs that protrude outwards in front of the main body.

 

The species is associated with many small deciduous trees and shrubs (this one I found on a Malus sp.), and was in fact a pest of hop (Humulus lupulus) when it was once grown frequently. I bet beer lovers were furious...

 

...and don't touch them, as (like many caterpillars) they induce undesirable reactions. Coming into contact with the poisonous hairs or spines may cause skin rashes - or even a hypersensitivity reaction.

 

Sources:

 

An overview of the moth and its habitat.

 

Health issues associate with skin-to-caterpillar contact.

Distribution map of the species.

 

 

I had a similar caterpillar outside my home a few months ago

A rusty tussock moth apparently, funny looking little things!

[Kveldssanger]

They are incredible. Their detail is astounding.

[Kveldssanger]

18/09/15. Fact #35.

 

Białowieża National Park is one of the very few areas within Europe that still retains an entirely extant ungulate assemblage - European bison, red deer, roe deer, moose, and wild boar, in addition to the wolf and lynx, all roam the forests. At times, livestock have also grazed the forests, though no grazing is present currently.

 

The uniqueness of the National Park, which still retains species otherwise hunted to extinction in other regions, is scientifically intriguing. Białowieża provides for what 'could have been' if other forests were also left to their own devices, and man did not hunt species (sometimes to extinction) or introduce species for a given reason.

 

Białowieża currently has very few forest gaps - less than 5% is open grassland or sedge / reed marsh along the riparian strips. Tree regeneration is a continuous process beneath the canopy of old stands, and also within canopy gaps. The browsing of ungulates, contrary to Vera's view of old forests being a mosaic of open to closed canopy stands, has had little lasting impact upon species composition or stand 'openness'.

 

Seedling recruitment is however impacted by ungulate browsing, as is concluded by studies that have spanned around 70 years. Seedling recruitment of more palatable tree species was of course lower given the ungulate browsing, though the 'landscape of fear' created by the presence of wolf and lynx ultimately altered ungulate browsing habit that in turn was of benefit to seedling recruitment on the whole.

 

Source: Latalowa, M., Zimny, M., Jedrzejewska, B., & Samolijk, T. (2015) Białowieża Primeval Forest: a 2000-year interplay of environmental and cultural forces in Europe’s best preserved temperate woodlandIn Kirby, K. & Watkins, C. (eds.) Europe's Changing Woods and Forests: From Wildwood to Managed Landscapes. UK: CABI.

[Kveldssanger]

19/09/15. Fact #36.

 

Reproductive growth in plants is driven largely by the environment - light intensity, light duration, temperature, water supply, and other climatic factors will have significant impact upon fruit quality, yield, blossoming, bud dormancy (activation), pollen formation, and more.

 

For this fact, I am going to focus solely on flowers.

 

In the rawest sense, each sequential event (petal opening, anthesis, stigmatic secretion, pollen germination, growth of pollen tubes, maturation of embryo sacs, fusion of polar nuclei, double fertilisation, petal fall, and ovary growth - yes, there are a lot of them!) of the flowering process within plants is regulated by temperature. Where temperatures are low therefore, the process is slowed - this may have an impact upon fruit set.

 

Before flowers can begin to form, the buds must be exposed to the cold (adequate amount of cold varies on the species, though at 7.2 degrees Celsius between 50-1,150 hours may be necessary for different peach cultivars alone), and then be exposed to progressively-increasing temperatures. Of course, this doesn't apply for all species, however.

 

Source: Kozlowski, T. & Pallardy, S. (1997) Chapter 6: Environmental Regulation of Reproductive Growth. In Growth Control in Woody Plants. UK: Academic Press.

[Kveldssanger]

For those interested, I heard back from the Forestry Commission (Ken Adams) regarding P. nigra var. betulifolia cultivation. He had some great points, and linked me to his website on the Water Poplar.

 

See here. It's a great read.

 

BLACK POPLARS IN UK

[tree-fancier123]

that Polish forest park is pretty special, not heard of it before - some monster trees in there

 

'Patriarch' oak

[Kveldssanger]

That is a grand oak! I'm looking to go to the Carpathians in the coming years, though the Bialowezia National Park is also very tempting.

 

I am in the process of reading 'Plant Sensing & Communication', of which I am certain there will be many wonderful facts to share.

 

A very basic one for today, as I'm only on page 11 (!).

 

21/09/15. Fact #37.

 

Plants detect light when their receptor molecules (chlorophyll, xanthophyll (xantho = yellow), carotenoids, cyanophyll (cyan = blue)) absorb solar electromagnetic radiation (light). Such receptor molecules will only absorb the light if the light wavelength matches the wavelength requires to 'activate' the receptor molecule; otherwise, the molecule will not 'excite' and not 'oscillate' in a higher state. For example, chlorophyll will absorb red wavelengths and reflect green ones.

 

And thus was borne the reason for many different leaf pigmentations! The wider the range of pigments, the more light of different wavelengths that can be used.

 

Source: Karban, R. (2015) Plant Sensing & Communication. USA: The University of Chicago Press.

 

If you want to check out the wavelengths of the different pigments, they can be found online readily. They're in my notes somewhere, but I cannot find them at this moment.

Edited September 21, 2015 by Kveldssanger

[Kveldssanger]

Gotta' add this from the same source:

 

Plants mainly absorb red wavelengths. However, as the sun sets (dusk), the ratio of red:far-red wavelengths skews more towards far-red. As a result, plants will temporarily change their sensitivity to far-red light, by means of the Circadian clock, in order to still efficiently photosynthesise.