Thanks for looking.
I like the rocks and it color variation. I would try to work on the veggies a bit :)
The overall view is good. Agree about the trees. Don't know what model you used. Maybe try to increase their diffuse color to the maximum to see if you could make them lighter. Once you do that, consider some color variance (some dry) in the population.
Thanks for the suggestions.
You're welcome. One other thing, Jo Meder had put up a recent file on 'clumping' of populations. You might search that file and try it. It is fairly simple to use. One other thing re your image would be to close the spacing a bit on your tree population.