Magic of the Land( Races of the Wild, p. 152)
Your intimate understanding of the natural world allows you to imbue your spells with life-giving magical power from the land itself.
When in a natural setting, you can draw on the power of the land to imbue your spells with healing power. For the purpose of this feat, a natural setting is defined as any location not within a community and not a constructed area. "Natural setting" includes unworked caverns, but not crafted dungeons and the like. To use the feat, you must succeed on a Knowledge (nature) check (DC 15 + spell level), made as a free action while casting a spell. You can't take 10 on this check. If you succeed, each target of your spell is healed of 2 points of damage per spell level, in addition to the spell's normal effects. If the spell doesn't have a target entry, this feat has no effect. This healing power is positive energy, so an undead creature instead takes 2 points of damage per spell level. An unwilling creature can attempt a Will save (at the spell's normal save DC) to negate this effect. If the skill check fails, the prepared spell or spell slot is lost. You cannot use this feat on any spell with an alignment descriptor, nor with any necromancy spell. The natural world favors balance in all things, and thus does not support specific alignment-based magic, nor can its life-giving power be used to enhance the magic of death.