Hi.
1) Does damage reduction of bear form stack with other passive DRs? For example, if I am a half elf barbarian dilettante, I have 3 DR at all times.
If I am Nature's Warrior, I get +7 DR in bear form. Will it be 10, or does bear DR overwrite barbarian's DR?
2) Does the Nature's Warrior DR stack with the capstone DR? Capstone gives 10 DR in bear form, prestige class gives 7 and 4 (first and second level). Will it be 21?

"Druid: Prestige Enhancement

Druid Nature's Warrior 1 (lvl 6 druid, 4 ap, requires druid bestial nature 1 / druid vengeful hunter 1, requires one of druid aggravate/druid shifting rake) You are a warrior of nature, in touch with the wild beast within you. Your melee and ranged attacks deal an extra 1d6 sneak attack against enemies with less then 50% health, and you gain an extra 2 DR when blocking. While in any wolf form, you gain 1d6 sneak attack bonus. While in any bear form, you gain a 7 bonus to physical resistance.
Druid Nature's Warrior 2 (lvl 12 druid, 2 ap, requires druid nature's warrior / druid bestial nature 2 / druid vengeful hunter 2, requires one of druid fatal harrier/druid reaving roar) You are a warrior of nature, in touch with the wild beast within you. Your melee and ranged attacks deal an extra 1d6 sneak attack against enemies with less then 50% health, for a total of 2d6, and you gain an extra 2 DR when blocking, for a total of 4. While in any wolf form, you gain an additional 1d6 sneak attack bonus. While in any bear form, you gain a 4 bonus to physical resistance.

Capstone Enhancements

Hierophant (lvl 20 druid, 2 ap) You are wise and skilled in the art of wielding divine magic to conjure aid and transmute the world around you. You gain +2 wisdom, and +1 DC, caster level and max caster level to your conjuration an transmutation spells. If you take hierophant, you cannot take the natural adept enhancement.

Natural adept (lvl 20 druid, 2 ap) You have mastered the art of wielding divine magic in animal form, and using it to empower your body in physical combat. While in animal form, the cooldown penalty for non-animal form spells is reduced from 2.5 times the usual length to 1.5. You also gain 2d6 addition sneak attack dice while in wolf form, and 10 physical resistance rating while in bear form. If you take natural adept, you cannot take the hierophant enhancement. "