More RAM will always help and more processor speed as well.
You need to isolate some of the items that are taking the time to rendering. Try rendering just the trees or just the grass... then turn on and off shadows. Minimize the amount of lights in your scene for these tests as well.
Once you find the object(s) that are taking most of the time to render, play with their settings, again with everything else turned off. Trees in the foreground will need the detail, but the trees in the background will NOT need as much detail. I sometimes turn off the shadows for every other tree in my background, not many can tell the difference.
Robert J. Garand
ArchiCAD USA 28-Build 3110 USA FULL
Windows 11 Prof (64 bit) - Intel i9-14900K CPU 3.20 GHz - 64 GB RAM - NVIDIA RTX 5000 Ada Generation