Point well-taken. Sorry if I offended. I was being catty.
I actually ONLY shoot with a DSLR. I've got a Nikon D7000 that goes right next to my ultralight hammock and my $300 sleeping bag :) it's funny trimming ounces by cutting off tags and then putting a 2lb camera in your bag, but that's my life.
At any rate, the entry level DSLR's like the Nikon D3100 are pretty terrible. I think their "niche" in the market is to let hobbyists play around with DSLR features, which goes a long way to image quality but for an amateur, is probably just going to result in disappointing pictures. By disappointing, I mean that it'll likely be on par with a point-and-shoot and look rather generic, when you might expect to have "Nature" magazine shots when you put your card into your computer.
A more expensive DSLR, like a D7000 or even a D5100/5200 is going to do a lot of the work for you and produce consistently good to great images using a kit lens and the "Auto" setting, which for casual backpack photography is great.
You have to pay out the $1500+ just to get that system, and it's still an absolute brick.
Enter the Micro 4/3 format. You get all the potential for image quality of the D3100 or D5100, since you can mess with aperture, shutter speed, color correction, white balance, etc. PLUS you can purchase zoom lenses and expand your shooting capabilities substantially. And it weighs half of what a DSLR weighs, and packs in a smaller bag.
So, Micro 4/3 is what I really believe to be the ideal format for UL backpack photography. I sometimes ponder trading out my DSLR for one. But no, I'm in love with my Nikon, I could never stray.
P.S. A good photo-editing software and the ~2 hours it takes to master the basics of it will go MUCH farther, dollar for dollar, than a camera upgrade. I would take a $200 camera and PS Lightroom ($150) over a $350 camera every single time. If you're a student or professor, PS Lightroom is $75.