(Arboricultural-styled) 'Fact of the Day'

[kev7937]

You certainly notice it if you take one down on a busy road

[Kveldssanger]

Got a massive line of 'em down by a railway bridge. Huge beasts, sitting in an area that floods even in late spring. Dreading the day they all spontaneously die.

[daltontrees]

Sounds about right.

 

See, the leyland is good for three things:

- birds

- pollution capture

- annoying neighbours

 

 

4 things You forgot garden centre sales.

[daltontrees]

I do agree with you, yes. I shall double-check statements like that from here-on-in.

 

Yes, but don't let it slow you down from posting daily. Us followers can do the double-checking. It might all stick in the memory better if it is read critically.

[daltontrees]

OK, checking the suspect figure about pollution filtering for a tree taking up 50,000 cu.m of air. The most polluted cities in the world have 100g/m3 of pollutants. That's 5,000kg of pollutants being filtered. 5 tonnes. A day?

 

So here's the follow-up question. If the tree was a cooker-hood, the filter would be bunged up within a few hours. If the tree absorbed 5kg of pollutants a day, it would put on 1.8 tonnes of weight extra every year, and would probably collapse. But it doesn't. where does that weight go?

 

I am taking the 50,000 cu.m. at face value.

[treeverine]

Just love this thread! Great facts too add to our knowledge base. Well done KV!!

[Gary Prentice]

As I understand the trees role in particulate capture, the particulates aren't filtered by the tree but adhere to the leaves/needles/twigs/bark etc. then are washed off and adsorbed into the underlying soil. They act as a filter that is continually being cleaned. I've seen some figures that showed, I think, that they are particularly good in this respect of 'capturing' the smaller sized particulates - those most harmful to health and can be located miles downwind of the source and still be affective.

[Kveldssanger]

OK, checking the suspect figure about pollution filtering for a tree taking up 50,000 cu.m of air. The most polluted cities in the world have 100g/m3 of pollutants. That's 5,000kg of pollutants being filtered. 5 tonnes. A day?

 

So here's the follow-up question. If the tree was a cooker-hood, the filter would be bunged up within a few hours. If the tree absorbed 5kg of pollutants a day, it would put on 1.8 tonnes of weight extra every year, and would probably collapse. But it doesn't. where does that weight go?

 

I am taking the 50,000 cu.m. at face value.

 

Would the air not be taken up for photosynthesis, and predominantly released back as waste products (oxygen primarily, though also VOCs)?

[Kveldssanger]

20/08/15. Fact #11.

 

A recent study that attempted to look at the impact of forest-based 'rehabilitation' for patients suffering from severe exhaustion disorder concluded that forest visits should be integrated into part of a wider rehabilitation programme, because of the benefits such visits provide in terms of, particularly, mental well-being.

 

All visits to the forest were two hours in duration. Patients reported that, once accustomed to the silence (which may have taken several visits), they felt at peace when alone in a forest setting, in addition to feeling safe and secure.

 

All 19 patients had their own desired places within the forest and agreed that the natural beauty of the forest was appealing, with the vibrant colours, natural sounds of the wind, birds, trees, and other animals was relaxing. Patients also began to look forward to their visits over time, and the visits provided the patients with time to reflect upon their lives and process their thoughts. Positive thinking was improved, as was mood.

 

Without wanting to drag on, the research project basically concluded that forest visits are very much beneficial, and whilst not a treatment that should be a stand-alone, when coupled with other methods of rehabilitation, access to green space / woodlands / forests is critical.

 

It's a nice succinct report, and I have linked it below as it's open access.

 

Source: Sonntag-Öström, E., Stenlund, T., Nordin, M., Lundell, Y., Ahlgren, C., Fjellman-Wiklund, A., Jarvholm, S., & Dolling, A. (2015) “Nature's effect on my mind”–Patients’ qualitative experiences of a forest-based rehabilitation programme. Urban Forestry & Urban Greening. 14 (3). p607-614.

[Kveldssanger]

20/08/15. Fact 11.5.

 

Reading Shigo's Modern Arboriculture and came across an interesting comment on p34, that I have paraphrased as follows:

 

Where a tree is stressed the use of chemicals to inhibit flowering and initiate fruit abortion and early abscission may be desirable. In species such as Ulmus americana, where seeds mature before leaves form, the inhibition of the reproductive process may reduce further stress in specimens that are already succumbing to the impacts of stress (for whatever reason).

 

I suppose the same could be suggested for Acer saccharinum, where the samaras ripen and fall in spring, and for particular Prunus species such as P. dulcis, P. avium, and other species that flower before bud break. This tactic could be used in particularly important specimens, perhaps?

 

Source: Shigo, A. (1991) Modern Arboriculture. USA: Shigo & Trees, Associates.