Pretty sure its a type of pollard willow, judging by the thick bases of the trees. Not entirely sure about the bright green colour, this could just be the image or the newly developed leaves that formed, or a specific variety.
A pollard willow is a normal willow tree that is pruned back to a specific size each year, which gives this beautiful thick base and "tufts" of branches. Often used for basket and fence making, due to the springy young offshoots every year.
Salix Alba and sub-varieties are the main species used to do this in my area.