You asked specifically about forestry in Sebastopol. No. But, from Sebastopol it is a short trip (20 minutes or so) to reach the beach, the redwoods, or Santa Rosa.
I love Sebastopol. Especially if you're looking for that "small town" feeling. However, it is not a cheap place to live. The independent grocery stores are fabulous, but you might as well be shopping at Whole Foods, the prices are about the same. There is a Safeway and an Albertsons in town, or else you have to head into Santa Rosa for more choices. There is a great local produce stand, and Farmer's Market every week during the warm season.
Organic is a way of life in Sebastopol, there are vegetarian restaurants, and nobody would look twice at someone babywearing or breastfeeding.
On the other hand, Petaluma isn't going to be much, if any cheaper. About half of Petaluma (W of 101) is "small town charm" and the other half (E of 101) is mainstream America. Petaluma is much bigger than Sebastopol, they don't have the local ordinances controlling growth that Sebastopol has, and it is further to drive to get to the redwoods, or the beach. It is closer to San Francisco and Marin, though (if that makes a difference to you). There will be less AP "options" in Petaluma than there will be in Sebastopol, because so much of it is mainstream.
If you're looking at renting, rent in either place is going to be pretty comparable. To buy, they'll probably be pretty comparable as well. That is to say, very expensive.
Which one you wind up in may need to depend on the work situation, as in where will work be, how long a drive, how heavy of traffic (cause traffic is awful in SoCo), how many backroads are available, etc.
If the commute isn't an issue, but the cost is, you may want to look into Guerneville or Cazadero. It is cheaper (although not cheap), it's further out, smack in the middle of the redwoods (I made an offer on a house there once, 2/3 of an acre, all redwoods, the back porch extended out to within an inch of a giant redwood, beautiful), the Russian River is right there, tons of nature. The big problem with Guerneville is that floods are not uncommon, which can mean closed roads, and always ask about flooding before signing on the dotted line.
If you have any more specific questions, feel free to PM me.