Trees and pollutionI Was walking through town earluer today

[Steven P]

So trees are brilliant for the environment, - havens for wildlife, insects, shelter, nests, give out oxygen, take in carbon dioxide

, sort of carbon neutral for building (better than concrete) and burning  - a big list.

 

Plant trees in the city centre, or along main roads and they suck in a lot of bad stuff leaving the air cleaner... where does all the bad stuff go to? Is it locked into the wood (so if I burn it later it is released into the atmosphere again) does it get converted to other things? Does it go through the tree and come out into the soil?

 

Thanks if anyone has any ideas

[Gary Prentice]

Airbourne particulates get trapped by the leaves and washed off to the floor when it rains.

 

Tree roots can adsorb some pollutants and, I think, these are retained within the tree. The process is called bioremediation and it’s more involved than that, but I’ve forgotten most of what I’ve read about it.

[Stubby]

Bit like a DPF then . Absorbs all the crap and then on the regen cycle lets it all out to the atmosphere ! ?

[Gary Prentice]

Only the good stuff (mostly) like oxygen Stubby.

 

Its amazing the shite that trees can bioremediate into less harmful chemicals. 

[spandit]

Sure I read somewhere that trees in towns can actually make pollution worse by impeding airflow. I'd still rather have more trees than fewer

[Stubby]

1 hour ago, Gary Prentice said:

Only the good stuff (mostly) like oxygen Stubby.

 

Its amazing the shite that trees can bioremediate into less harmful chemicals. 

I meant when you burn them .

[Stubby]

9 minutes ago, spandit said:

Sure I read somewhere that trees in towns can actually make pollution worse by impeding airflow. I'd still rather have more trees than fewer

Yep I read that on here too .

[peatff]

35 minutes ago, spandit said:

Sure I read somewhere that trees in towns can actually make pollution worse by impeding airflow. I'd still rather have more trees than fewer

 

Who told you that, Sheffield council ??

[openspaceman]

2 hours ago, Stubby said:

Bit like a DPF then . Absorbs all the crap and then on the regen cycle lets it all out to the atmosphere ! ?

The DPF traps fine particles which consist of soot and polycyclic aromatic carbons adsorbed onto them. When it regens, or indeed any time it is hot enough it turns the carbon into carbon dioxide and the PAHs into carbon dioxide and steam.

[Gary Prentice]

47 minutes ago, spandit said:

Sure I read somewhere that trees in towns can actually make pollution worse by impeding airflow. I'd still rather have more trees than fewer

You're right, by reducing airflow they can concentrate particulates close to the emitting source and raise levels. Buildings do the same and they don't trap particulates. But even when sited at distance from a pollution source, they act as effective filters and reduce pollution to the leeside of the canopy. Basically we need more trees properly chosen and sited, and more evergreen species than we currently use.

 

Keith Sacre was complaining that the average landscape architects palette of trees consisted of around a dozen species. There's (almost) always something suitable for any given situation. Did I mention that we need more trees?

45 minutes ago, Stubby said:

I meant when you burn them .

I think that they change the chemical formulae into less harmful stuff, so less of an issue when they are burnt. Tree are good  I've an article somewhere about using trees/tree pits for surface water runoff in I think Manhatten. The run-off is/was so polluted that it was affecting the river where it ended up. The solution was to run it through 'tanks' with trees and shrubs growing which cleaned it before it flowed onward into the Hudson. All kinds of shite like oil, brake dust and other stuff from vehicles.