hello everyone, i am new to this forum, and this is my first post. please excuse my english (i am from Croatia).
willow is growing fast and likes wet soil.
but it does not burn hot. actually it burns out quite quick also.
ash can stand damp soil well also, but it has much better wood. for different uses. ash burns much better (good also for bows, carving and stuff).
but willow (and poplar and similar soft wood) grow faster than ash.
oak (Quercus robur) also loves swampy terrain, and has excellent wood (branches can be used for fire wood, and tree is a shame to burn). oak also grows slow.
in my country people widely use black locust for firewood. it grows quick, and burns very hot. also good for bow making, toolhandles and other stuff.
Black locust can stand dryer soil, but i have seen it in swampy areas also.
so that would be my first choice.
zora