Some species of tree e.g. Silver Birch will not season properly unless split or de-barked, as the bark is very dense. Freshly felled wood should be cut, split and stacked in a well-ventilated shelter for at least two summers.
All species of wood have roughly the same energy content in proportion to their weight when fully seasoned.
What is the best wood to burn in your antique stove? – Free wood! Factory offcuts and waste wood are an excellent source of fuel, provided it is dry, seasoned and uncontaminated.
Green timber has a high moisture content and should not be burnt in your antique stove. Some species have a high normal moisture content, e.g. Elm, whereas others such as Ash, although initially lower in moisture content, still contain 50% water when green.