[permaculture] "thirsty " trees....

Scott Hitchins ScottH at wcig.org.au
Wed Sep 4 02:21:15 EDT 2002

Hi all, I just thought I'd throw this into the discussion: Rainfall caused by trees is not just a matter of transpiration:  My understanding is that trees are also responsible for the production of organic particles which are of a suitable size to act as nuclei for the formation of raindrops, i.e.. It doesn't rain in a deforested region because there is nothing suspended in the atmosphere for the water vapour to coalesce around and hence become heavy enough to fall to the ground.  I seem to remember Lord Bill referring to this in his Big Book, and giving an example of this going to extremes in Kenya, where the stomping of dried tea leaves on tea plantations (to compress for shipping) was resulting in torrential rains destroying the plantations, simply because of the large quantity of particles stirred-up by this activity.-This is why silver(nitrate?oxide?)is used for cloud-seeding: the particles are just the right size; i.e. its a physical rather than chemical property that desired. 
Scott Hitchins

-----Original Message-----
From: lfl at intrex.net [mailto:lfl at intrex.net]
Sent: Wednesday, 4 September 2002 5:53 PM
To: permaculture at lists.ibiblio.org
Subject: Re: [permaculture] "thirsty " trees....

lfl at intrex.net wrote:

> Maybe this is proof that terrain cleared of plant life brings drought.
> Plants, especially trees and understory transpire (evapotranspiration)
> and give off moisture to the atmosphere. They shade the ground and prevent
> moisture loss from that source. Moisture begets plants which beget biomass
> and nutrients which beget more plants and a diverse, stable ecosystem.
> This system helps to prevent soil erosion, nutrient loss and 
> demineralization.

See this website for an experiment in reforestation to increase rainfall.
Why does is rain so much in the tropical rain__forests__?

Reforestation finances drinking water.

lfl at intrex.net

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