Hi Ekka
Thank you for the response.
We live in central London, Dartmouth Park a cross the road from Hampstaed heath ( fantastic trees ), and a few blocks away from Higate cemetry where amongst others, Karl Marx is burried. All the houses in the area were built between 1820 and 1880, on what is typically London clay ( most the Thames valley has this substructure ) As the climate changes, we had a rather dramatic drought last year, and a hose pipe ban for several months, the clay has been drying out more excessivly and causing more cases of subsidence. Everything I have read on this matter ( most coimprehensive is a 2004 report by Cambridge University ) says that a tree whould need to be dramatically cut back over 50% to make any real difference to the amount of water it extracts ( they suggest 70%) This corrolates with what you have said above. This is really dramatic for a tree and would need to be done regularly to keep its water usage low.
This is why I am keen to find a tree which inherently uses less water. Thanks for the point about fruit trees, makes a lot of sense.
I was also thinking about a false Acacia. It does not have a heavy canopy, and again I assume that because it originated in the savanas of Africa it would inherently not need or use too much water.
I'm very keen to hear more on this topic.
best regards
Royi |