Algeh gave a great summary of the kinds of forests you find out here. I'll go ahead and echo the sentiments on forest fires being a pretty significant danger. There is a neat little oddity you could toss into your world. High elevations are kind of part and parcel with this area, and a neat thing happens at the point where elevation and conditions are no longer conducive to tree growth. You get an area called the Tree Line, and at high elevations, you can wind up with very old pine trees that are shorter than you are. It's really kind of cool to see.

And I'll also echo the sentiment that traditional sight-based navigation becomes incredibly difficult. Without something like a compass, getting lost is super easy between the limited sight-lines, lack of landmarks, and canopy cover obscuring the stars.

Also, you could consider the effect that a non-native invasive species could have, and how that might change the environment. Invasive plant species (like Russian Olives here) tend to move in and choke out the native plant life, which could lead to drastic ecosystem changes. Something like the Japanese Pine Beetle could have a tremendous impact on all sorts of things (for us, it has a strong tendency to affect the way forest fires work). And that's just stuff that target native plant life. Something more fantastic like alien plant life from a meteor strike could have even stranger effects.