Since the dawn of history, human societies have ascribed sacred status to certain places. Areas such as ancestral burial grounds, temples and churchyards have been given protection through taboo and religious belief. As many of these places have been carefully managed for many years an interesting side effect has occurred—the sites often retain more of their natural condition than surrounding areas used for farming or human habitation. As a result, they are often called “sacred natural sites”.
Today, as many other natural habitats have become degraded, researchers worldwide are increasingly interested in the role of these sites in biodiversity conservation. Most of the world’s belief systems, including Christianity, give places sacred status. In Mediterranean Europe, for instance, the grounds of churches—with their associated ancient trees—have become important sacred natural sites.
One of the best examples is in the mountainous region of Epirus in northwestern Greece. In the municipalities of Zagori and Konitsa almost every village has one or more sacred grove. These places have been protected through religious belief systems for hundreds of years.
The groves are either protective forests that lie uphill from the village, or groups of mature trees surrounding outlying churches, monuments or other works of religious art. Activities such as the cutting of trees or livestock grazing have been either prohibited or strictly regulated in these places (and disobeying these prohibitions sometimes led to excommunication).
We have recently been studying these Greek sacred natural sites as part of our SAGE (SAcred Groves of Epirus) project. Our team wanted to find out, using a rigorous research approach, whether these sites are more biodiverse than other forest areas, and, if so, what lessons conservationists could learn from this.
To do this, our international and multidisciplinary group has recently completed the world’s first replicated systematic investigation into the claims that areas conserved as sacred natural sites are more biodiverse for different types of plant and animal.
For our recently published study, we selected eight SNS in Epirus that covered a wide range of environmental conditions. Each was closely matched with a nearby non-sacred “control” forest which had been managed conventionally—sometimes through natural regeneration. We then conducted a detailed inventory in each site, of eight different groups of organisms. These ranged from fungi and lichens, through herbaceous and woody plants to nematodes, insects, bats and passerine birds.
We found that sacred natural sites do indeed have a small but persistent biodiversity advantage. This is expressed in a number of ways, most clearly through the existence of more distinct communities of species among the sacred groves than in the control sites (this phenomenon is known as beta diversity).
The group with the most notably higher biodiversity in the sacred natural sites than in control sites were the fungi. These often grow in dead wood or old trees, which usually get removed in conventionally managed forests. Of the species of passerine birds (a group that includes many songbirds) that are designated as having special conservation importance at a European level,