Many say that these trees do not allow vegetation growth in the areas beneath them, because of certain chemicals they release from their roots, although I have never been 100% sure about this.
What do you think about them (+ve and -ve)?
I wish to hear some of your toughts, or actual facts about their effect on our ecosystems.
When I bought the new camera (mid Dec) I went to wied il-kbir, Qormi to try it out. I parked near a house at the valley which had a large Datura plant and took my first photos on it. The owner, an old man of about 65yrs, came to talk with me and spent some 45mins in our discussion.
He was a wise person full of experience, and he was telling me that he loved plants and trees (not as much as the feast of Saint George) and also told me that he planted those 5 or 6 eucalyptus in front of his house, opposite side of the valley.
I remember what one of our diploma in Agric lecturers said to us about the-ve effect of these trees on surrounding flora that Keith (co-student!) mentioned in the post. So I told him immediately that it was not a good idea because of this -ve thing.
He soon replied that this is quite a fallacy and invited me to go under the trees and seee with my eyes. Actually there where several herbaceous plants (Crucifers in particular) and also a conifer close to them that he claimed that he also planted. So in practice he was right.
Than I remember well that he added "look how beautiful trees they are, tall, evergreen, full of birds, and lots of shade in summer" He could also have added that they prevented soil erosion due to running water of this large valley.
I had no words of wisdom to reply back, and so I had to tell him that he is right!
So Keith, I have also my little skeptics about how bad these trees are in maltese environment. Afterall it is better to have an alien tree rather than none at all.
If you want to visit this place tell me.
I am sure that the other members have something to add.
I also have regularly encountered vegetation under these trees, and thats why I was suspisious.
I think that maybe the lack of vegetation in some cases is due to the huge span of the tree and the shade it creates, which in turn may not allow small plants to survive.
Secondly it is also true that they prevent or retard the growth of plants around them. This is because the dead, fallen leaves that fall on the ground slowly give off certain chemicals that interfere with the growth of other plants. It is this leaf litter rather than the plant itself that retards plant growth.This does not mean that absolutely nothing can grow under eucalyptus. After all some of the fast growing opportunist plants can grow on almost any type of terrain.
This is one of the ways in which Eucalyptus trees minimise competition from other trees in their native habitats.
The point is that when we are planning to make new tree zones (forrests) we should not opt for Eucalyptus and other aliens but on the other hand I dont like to see authorities cutting down these large trees without replacing them with something else or put small teeny-weeny trees like olives that grows slowly and would not have the effect of a large tree as eucalyptus.
Conifers would be good but expensive.
Better a tree than none in our semi-desert land.
so 10x Robcar for giving me the correct answer.
I also agree with Stephen that these trees should not be cut down or burnt ( again suggestions from an expert,) but should be left to grow as they are.
The least that could be done to decrease Eucalyptus, is that the sowing of these trees outside should be banned by the authorities.
Instead Maltese indigenous trees should be sown.
The hunters asociation would have to promote this campaign I think, because they have planted 99% of the Eucalypts out there!
Notwithstanding, in Sicily i had the opportunity to see the roots of Euc. trees due to exposure by erosion, and they are impressive - easily 20 meters RADIUS from the tree, just under the surface. So it will also compete heavily for water.
In an island like malta where eucalyptus and pines are beingt planted even inside the last natural Tetraclinis forests you should be very choosy about what you plant. In a few decades you are going to have more than enough forests in Malta but by than it will be to late to correct most mistakes. A diverse garrigue might be just one or two feet tall but it takes a much longer period to develop than a forest.an olive tree might grow slower than some other species but some maltese olive forests house a great diversity of wild plants. (I will show you some next spring).
However I agree on Sdrako's point.
Forests is inversely proportional to biodiversity of herbaceaous plants especially the small ones.
Are you coming in Spring! Great... BTW I passed a good word at mepa for you