To second Zizka: I like the idea of varying the foliage but the way you're doing it with your latest tree variations, with such a marked division is pretty unnatural; as is it had been dipped in paint. As per the photo ref. you've picked out try doing so more irregularly and organically as ageing leaves might.
There are a lot more ways you could mix it up beyond a simple palette change though: how about varying the amount
of leaves, perhaps having some trunks almost bare; that's kinda the crux of the season after all
. You could even branch out into a proper mixed woodland really for a really good variety of shapes, sizes and colours both of the tree and leaves themselves: you seem to be starting to treat all the foliage (trees, bushes, new cliff edge grass) with a very similar texture.
New rock-face looks ok but be careful not to overwork it; the previous edits look great partly for the lack of detailing in some places. Quickly as reference to the problem of alternate interpretation before: The big tonal difference is certainly the main issue but other continuities/interactions would help too eg. bits of rock jutting out into or overlapping the grass underneath, climbing plants etc. with an origin in the lower level.
The older stand-alone rocks look pretty odd next to the new cliff, they might be from different games. Why not apply some of the cliff improvements thataway?
The start you've made on the water looks very tropical. I'd think about going darker, murker and put more emphasis on the surface and the plants there (duckweed, lillies, rushes, irises) in respect to the latitudes and light levels of the season.
Heh, apologies for the massive, wordy post, I'd been meaning to for a while