I've noticed that since the addition of "better" forest generation some months ago, load times seem to have increased a lot on the devices I usually play (A toaster laptop and an android tablet) and the issue has only gotten worse and worse as time passes.

Right now my current guesses for which trees are increasing cpu/gpu load are the big masses of trees that are generated on the borders of the maps, which I've highlighted in the next picture.

These stretch over those two sides of the entire map, and since (my guess again) each tree sprite has to be rendered 1 by 1 each time the map is loaded, they only end up causing performance issues on lower end devices and probably over a wide range of, new and old,  android devices as well.

Of course, there's probably other factors that could be adding up to these performance issues but it's just that I started noticing an exponential increase in load times right after the last forest generation code update.

Hey - there's an option called "Fast World Map" that turns off all of that. The mass of trees is actually just a single sprite, so it's doubtful it's causing any real lag as such.  We did increase the number of single trees, but turning on fast world map will remove all reflections and shadows, drastically decreasing the number of sprites.