Complex sentence: They have this rules against interacting and adopting foreign ideas, technology, and way of life, and also set of taboos such as not to cut the trees or harm the forest creatures in order to conserve their natural ecosystem.
Split into simpler sentences: They have this rules against interacting to outsiders and adopting foreign ideas, technology, and way of life. They also setted of taboos such as not to cut the trees or harm the forest creatures in order to conserve their natural ecosystem.