So after much thinking, my first plan was to plant a tree next to my home, in replacement of another one that died and has been removed. This way, I just replace what has come to be missing.
I then decided to wait for december 5th to plant the first tree, in honor of His Majesty the King of Thailand, Bhumibol Adulyadej, who relentlessly repeats how important it is to plant trees for everybody's health, wealth and spirit. I also decided to plant that first tree as close as possible to the heart of the King's birthday celebrations.
This is how I found myself digging a (very small) hole in the ground, amidst a crowd of bemused Thais, all of them wearing pink shirts, smiling and kidding me around. They pretty much understood my purpose and the symbolic date without need for explanations, and took turns for a series of pictures with me and the newly planted tree. Just too bad i didn't bring my camera, or thought of getting a copy...
The first tree planted (Dipterocarpus), after one week
My wife and I bought bottles of water (forgot to bring some), watered the tree, planted a flag next to it, and that was it ! Since then, it got 2 liters of water almost every days of this past week, and looks great ! We came back yesterday with another same tree, to fill the available spot right next to it.
only 40 cm high, but already looking forward to reach the sky !
I now wish to continue this fun and useful activity, and have already noticed some suitable spots for more trees ! :D