Treated as one level higher when casting spells?

[ericpants]

Gnomes with the racial trait pyromaniac are treated as one level higher when casting spells with the fire descriptor. What exactly does this entail? Does it raise the DC, damage, duration, or area of effect for fire spells cast?

[Quandary]

When does spell DC ever depend on your character level? It doesn't.
Some spells' damage, duration, or area depends on Caster Level. That's what this modifies.
But's it's particular to each spells' parameters, not every spell's damage/duration/area scales with Caster Level.
Other effects besides those listed can also scale with Caster Level, it depends on the spell... but that's what this effects.
I have no idea why this rule was worded in such a non-standard way, instead of as a bonus to Caster Level.

[Bizbag]

It also means you get a +1 bonus to your CL check to defeat spell resistance if your spell is a [fire] spell.

[Nefreet]

And concentration checks.