The sabbatical year
Exodus 23:10-11 (NAB)

For six years you may sow your land and gather in its produce. But the seventh year you shall let the land lie untilled and unharvested, that the poor among you may eat of it and the beasts of the field may eat what the poor leave. So also shall you do in regard to your vineyard and your olive grove.

Leviticus 25:2b-7 (NAB)

Speak to the Israelites and tell them: When you enter the land that I am giving you, let the land, too, keep a sabbath for the LORD. For six years you may sow your field, and for six years prune your vineyard, gathering in their produce. But during the seventh year the land shall have a complete rest, a sabbath for the LORD, when you may neither sow your field nor prune your vineyard. The aftergrowth of your harvest you shall not reap, nor shall you pick the grapes of your untrimmed vines in this year of sabbath rest for the land. While the land has its sabbath, all its produce will be food equally for you yourself and for your male and female slaves, for your hired help and the tenants who live with you, and likewise for your livestock and for the wild animals on your land.

Against wanton destruction
Deuteronomy 20:19-20 (NRSV)

If you besiege a town for a long time, making war against it in order to take it, you must not destroy its trees by wielding an axe against them. Although you may take food from them, you must not cut them down. Are trees in the field human beings that they should come under siege from you? You may destroy only the trees that you know do not produce food; you may cut them down for use in building siege-works against the town that makes war with you, until it falls.

Protecting species
Deuteronomy 22:6-7 (NIV)

If you come across a bird's nest beside the road, either in a tree or on the ground, and the mother is sitting on the young or on the eggs, do not take the mother with the young. You may take the young, but be sure to let the mother go, so that it may go well with you and you may have a long life.

Precaution
Deuteronomy 22:8 (JPS)

When you build a new house, you shall make a parapet for your roof, so that you do not bring blood guilt on your house if anyone should fall from it.