Birch versus Oak : Who drops leaves first and why.

Below 2 pictures of the same 2 trees are taken by me in my garden recently but with a month in between and they clearly show that a birch (left tree) drops it leaves earlier than an oak (right tree) . But why?

If you do the same in spring you will notice that the birch is a bit later than the oak with forming new leaves. The reason of both differences is that a birch's natural region is the northern hemisphere whereas an oak (there are 600 species) is also seen on the northern hemisphere but not the coldest regions like the birch.

Birch family name is betula

Range of Betula

So the birch cannot afford to wait too long to drop it's leaves as winter comes in quickly and same for the spring; making leaves too early is risky in the nordics as winter can last very long. The tree apparantly does not know that the region where I live is more moderate, it just drops it leaves as programmed in it's "genes".

that's all faulks

Goldrooster