Better Forests

Added shrubs. They are generally rare except in forests severely stunted by cold and/or altitude.

Better Forests now affects swamps; they vary in height and density, and sometimes have dead trees, occasionally only dead trees.

Added Swamp Willow

Fewer Beehives on evergreens

Fixed a bug blocking sapling generation

Reduced stunting with altitude for Grove and Acacia trees.

Fixed a bug with biome-specific height changes

Fixed a memory leak and improved performance