Does chaining yourself up to a tree really save trees, does it really stall any kind of growth in the ever increasing deforestation on a global scale ?

No, but torching the dead trees they clear-cut helps.
Cutting down a few trees of your own and block a road, that helps.
Putting a rail-road derailing devise down where they transport it out helps, or simply cutting it.
Making the companies pocket scream and torching their cars or businesses helps.
Making the owners/decision makers scared by harassing them and smashing their car helps.

Voting does fucking nothing.
Stop telling yourself it does. It doesn't.
We wouldn't be allowed to vote if it mattered at all.