The island where I live is a national park and despite being expensive to get to has around 200,000 visitors a year and the main activity is hiking in the mountains. Other national parks, like this one, have the problem of too many visitors and have had to prepare plans to protect the nature from the effects of over-tourism.
Now as I'm sure you're aware there aren't that many residences with gardens, but the ones that do have them, are invariably taken care of well. There are professional gardeners who do this but it is usual to only use a professional once a year as they are expensive, the rest of the time it's the owner who does it.
The status of Yakushima as a National Park and then as a UNESCO site was due to the efforts of one local man who galvanised support across Japan. It is a national crime to damage some trees here now. It was also due to the efforts of a small community in the north part that giant turtle beaches are now protected. In another thread I mentioned a cousin of my wife's who was a local politician in Chiba and who started a campaign to stop the destruction of small community parks and encouraged the planting of more trees. These are just a few examples of people fighting back and there are many more.