It helps conserve precious natural resources. Earth’s many unique ecosystems are made the way they are for specific reasons, and they are not renewable. Any chance we have to avoid damaging it, we should take.
You can take part in conservationist tourist activities by first avoiding support of any programs that hurt the land or animals; for instance, the majority of zoos and any landscaped parks or recreation areas that have torn down natural resources in order to find their space. There are tours and parks that enable the original land to be preserved and enjoyed, so you should look for those.