There will now be two 'groups' of timed duration realm spells.
'Normal' and 'sustained'
Normal spells will last their full duration unless dispelled or dismissed, even if the source/temple requirement to cast them is no longer met. By extension it allows many unit-affecting spells to be cast, and then the units can freely move beyond the magical network without the spell ending.
Sustained spells, however, require a constant supply of magical energy to be effective, and ends immediately if the source/temple requirement isn't met. There are fewer spells in this category; the various ley ward/trap spells are in this category.
