Sacred forests are found all over the world; they are not restricted to any religion or belief system. They are wooded areas linked to deep feelings of significance for local communities from a religious, spiritual, and practical perspective. Examples include the magnificent network of “church forests” found in Ethiopia, which preserve small pockets of old-growth vegetation in a matrix of intensive agricultural landscape, or the forests surrounding monastic communities in Europe, which are examples of long-lasting and effective religious land stewardships.
Sacred forests have also played a key role in biodiversity conservation. They have been described as “the oldest protection system for habitats on the planet”, preserving many natural habitats from overexploitation for centuries. This long-lasting protection has allowed local communities to benefit from various services the forests provide, especially in times of dire need. Such services include water supply, erosion control, and retreat areas. Given the importance of sacred forests for our society, it is important to understand how social and ecological processes have interacted in their formation; this remains a research question worth investigating so as to provide guidelines for conservation managers. It is especially relevant in an age of drastic demographic change, as has occurred widely in rural areas of the Northern Mediterranean.
Is the special religious protection applied to sacred forests reflected in their species composition and structure? Might different prohibition regimes give rise to different types of forest? In Greece, an international and multidisciplinary team led by the Ecology Lab at the University of Ioannina has tried to answer these questions by studying a network of sacred forests in the region of Epirus. Sacred forests have existed in the area since the Ottoman period (1479–1912) and take the form of small forest patches embedded in former active agricultural landscapes. In the northern part of the region, almost every village has a sacred forest nearby where Orthodox religious norms for hundreds of years preserved areas of forest through the times when forests were scarce in the area.
By studying the tree composition and structures of several such sites using species rank–abundance curves, dissimilarity indices and cluster analyses, the team of researchers has shown that the composition and structure of these sacred forests today is strongly dependent on past forest prohibition regimes (such as control of grazing, limited wood extraction, etc.) as well as environmental factors. Researchers were able to classify the forests’ vegetation into four main woody plant groups, with diverse vegetation structure and floristic composition, associated with variations in site environment, management, and prohibition regimes. When the forests’ vegetation was characterized by low-canopy trees and shrubby understorey, researchers found a significant association to higher levels of human disturbances, e.g. active grazing. Conversely, high-canopy forests with a tall understorey are generally associated with places that have limited anthropogenic pressure. This key finding indicates the strong role that traditional religious regimes and local management practices have had in shaping tree species diversity and structure in Greek sacred forests.
Our results show that the maintenance, and in some cases revival of traditional management regimes, is an important component for preserving sacred forests. As islands of mature trees, they have a significant conservation value but these are increasingly threatened e.g. by forest fires. Therefore, innovative integrated management to conserve both cultural and ecological values should be initiated, focusing on retaining and managing large-sized trees through reinstating former management practices (e.g. low-intensity grazing) and also management of the boundary zone and the surrounding matrix to reduce fire risk due to the growth of flammable vegetation. As well as the direct benefits for landscape-scale biodiversity, it would bring additional social payoffs (e.g. reinvigorated community involvement in maintenance of sacred forests), supporting local history and folklore.
This is of particular relevance today, as sacred forests in Greece have been included in the UNESCO National Inventory of Intangible Cultural Heritage. Acting now would support local communities in keeping cultural and traditional practices alive in the face of growing globalization.