The environment includes such things as terrain, flora, fauna, weather, and natural and arcane forces. All these elements - each aspect of the environment and each organism - form a tapestry known as the ecology. And like a tapestry of cloth, this one can suffer severe damage if a single thread is removed, no matter how ugly the thread.
a 32-page booklet containing the words of the inimitable Bara, feisty druid of the High Moor, describing the ecology of that region;
a 32-page booklet by the Lark of Suzail that gives her descriptions of the slithering inhabitants of the Serpent Hills; and
a brief booklet of tables to aid the Dungeon Master in determining random encounters for adventurers whose travels take them through these areas.
Those planning to explore these regions would be well advised to read the works herein to prepare themselves for the reptilian dangers of the Serpent Hills and the hazards of the High Moor - from its beasts to its protective druid itself!