Here's another interesting factoid supporting the notion that environmentalists and religious groups have more in common than the former sometimes acknowledge: Globally, religious groups own 5-10% of the world's forests and influence much more.
That hook leads into what I find to be a hugely interesting program coming out of the Biodiversity Institute at Oxford University, The Religious Forest Sites map (below). It's being compiled in partnership with the Alliance of Religions and Conservation and the World Database on Sacred Natural Sites.(In interest of full disclosure, I'm an advisor for The Bhumi Project, which is also backed by the Alliance of Religions and Conservation, as well as the Oxford Centre for Hindu Studies, but I have to say the work of ARC covers a lot of ground and this partnership was totally new to me.)
Currently the map is a bit thin in spots, with the great body of documented sacred forests being in Italy, Ethiopia, southern India, and Japan. Crowd-sourcing is a component of the project though, so if you've got a sacred forest that isn't already included, there's a form on the site to do so.
Some description on the work being done in South Asia, and the ecological implications, via The Guardian:
[Dr Sonil Bhagwat] has found that some regions of India feature one sacred forest for every 300 hectares. The biodiversity in these groves in also very rich. For example, in the state of Karnataka in southern India, he came across the "poison arrow tree" and rare plantations of fig. There are now under threat. In the sacred groves of the Kodagu district, nearly one-third of the macrofungi are not thought to exist anywhere else in the world. Bhagwat believes that mapping these forest will strengthen the legal rights of the religious communities who run the groves: "Where data is available about the boundaries of these forests, it will hopefully give the local communities an instrument to help argue that these are the sites that they have traditionally been protecting for a long time. They are sites which have lasted through several generations.
Read more: Save our sacred woodlands