Many states in India have what are called sacred groves or gardens of the gods. In Kerala they are typically called "Kaavu" for various deities - mostly old tribal deities, goddesses predominantly. In this age when creating gargantuan and mostly ugly places for worship seems to be in vogue, its good to understand how these old gardens (which I find to be the true spiritual abodes) performed a critical ecological function. Most of these groves had evergreen forest patches around, that were left uncut and undisturbed due to the fear and/or respect for the god/goddess believed to be living inside.
The most important ecosystem service that forest patches like "kaavu" provide is water. They are the points of origin for streams that later join to form rivers. They provide oxygen and sequester carbon, control the micro climate and help precipitate rains (or atleast used to). With ever increasing urbanisation, most of these have now become concretised temples with 1-2 large trees left standing as the last beacon of once beautiful evergreen forest.
I have been chatting up with people living close to these sacred groves and they say their wells are never dry even in peak summer, they wake up listening to myriad birds and the air is always cool and fresh. I wish these are prioritised over constructing ever larger, newer temples. No god would want to sit in your concrete mansions - they'd rather dance and make love in these sacred groves, truly the garden of gods. I asked mine and she concurs :-)