Hi there,
Let me jump in with a few suggestions, BUT, I have to say, I really love your work so far!
The flowers are much better now for distribution and colours. Check some real life examples for how they grow.
For the tree, lots of barks out there (guess choose something oak-ish), my take would be AmbientCG, PolyHaven or CGBookcase.
I’m not sure, but the mountain may be a bit better with more crackled, peaky, edgy complexity at the top. Since foliate covers the bottom, you may not need to re-do all, if you used a normal or position thingie, use it as a mask and add more noise over the top with whatever texture you like
For the grass? My very quick setup. What is the idea? More varied grass, based on the texture of the ground.
I don’t say it is the best solution, but it works
You add noise, or whatever you like to the plane, just make sure you use Position for coordinates.
Then copy this whole thing (I could not make attribute work), so copy this into the instance shader setup. You can also tweak the shades of the colour ramp, just keep the shapes and scale the same. (Pic 1-2)
Then mix (multiply most probably) this, with your own particle setup. Random per island adds even more extra. (Pic 2)
You can always pop in a map range to control the effect with the TO Min-Max.
Result? Random grass but controlled by the ground’s texture. Meaning you can create green vs yellow grass, or so. You can go much further with similar applications, but I stopped here (long day )
I used geo nodes for scattering (Pic 3), but no rotation or whatsoever, very basic, so make sure to check the videos down below
Also, I still love particles, I have some problems with geo-nodes, namely the compatibility with shader nodes, if it comes to landscape texture tweaks in the shader, and all that. Also procedural displacement is not a big friend of scattering stuff Anyways, lots of great tutorials, check out Ryan here, for a great geo-node tutorial (weight-painting approach):
Also, check out Blender Dude for more:
https://www.youtube.com/channel/UCeDY5-JV9q6PDl_TcOUVk5g
Cheers!