Woody Species Diversity and Conservation Value of Ethiopian Orthodox Church Forests: A Systematic Review and Meta-Analysis

In the highlands of Ethiopia, a landscape that was once covered in dense, continuous forests has been transformed over the last century by farming and settlement. Today, the native trees are largely gone, replaced by open fields and scattered settlements. Yet, amidst this widespread change, small pockets of green have survived, hidden in plain sight around the country's ancient churches and monasteries. For centuries, the Ethiopian Orthodox Tewahido Church has protected these patches of land as sacred spaces, forbidding the cutting of trees within their boundaries. These "church forests" are not just religious sites; they are living islands of biodiversity, holding onto the last remnants of the region's original dry mountain forests. Scientists have long suspected that these groves are vital for saving native plants from extinction, but the evidence has been scattered across dozens of separate studies, each looking at a different forest or a different region. Without a way to bring all this information together, it has been difficult to understand the true scale of what these sacred groves are protecting.

A new study brings these scattered pieces of evidence together to tell a complete story. Researchers gathered data from fourteen different scientific studies that examined church forests across four major regions of Ethiopia. They focused specifically on woody plants—trees, shrubs, and climbing vines—because these are the backbone of the forest ecosystem. By combining the lists of plants found in each study, the team created a massive, unified record of what is actually growing in these protected spaces. They checked the names of every plant to ensure they were all identified correctly, removing any that were not woody or could not be clearly identified. This process allowed them to see the full picture of the plant life that has survived in these sacred groves, rather than just looking at isolated fragments.

The results reveal a landscape of surprising richness. The researchers compiled a list of 310 distinct woody species found across approximately 80 church forests. To put this in perspective, this collection represents about 12.5 percent of all the woody plant species estimated to exist in the entire country. Even more striking is the fact that these forests are home to nearly half of all the plant species that are found nowhere else on Earth. The vast majority of the plants, more than 90 percent, are native to Ethiopia, meaning they evolved there and belong to the local ecosystem. Only a small fraction are non-native species brought in from other places. This high proportion of native plants suggests that the traditional way the church manages these lands has been remarkably effective at keeping the original forest community intact.

When the researchers looked at the specific types of plants, they found that trees made up the largest group, followed by shrubs and climbing vines. The most common families of plants included the legume family, which is known for its nitrogen-fixing abilities, and the spurge family. Certain species appeared again and again across different forests, including the Ethiopian juniper and the African olive, both of which are iconic trees of the highland landscape. The study also showed that the number of different species in a single forest varies greatly depending on where it is located. Forests in the Amhara region tended to have the most variety, while those in the Tigrai region had fewer. This difference likely reflects the varying climate and the history of human pressure in those areas. On average, a single church forest was found to contain nearly 75 different woody species, a number much higher than what earlier, smaller studies had suggested.

The research also highlighted the difference between forests surrounding a single church and those surrounding a monastery. The monastery forests, which are often larger and older, tended to hold more species than the smaller church forests. This suggests that size and age play a role in how well these sites can protect biodiversity. While the study found that the forests are doing a good job of keeping native species alive, it also noted that in urban areas like Addis Ababa, the mix of plants includes more non-native species, likely because people have planted ornamental trees there. This points to a need for careful management in cities to ensure that the unique character of these sacred groves is preserved.

Ultimately, this work confirms that Ethiopian Orthodox Church forests are not just leftover patches of nature but are active, thriving centers of conservation. They are holding onto a significant portion of the country's plant heritage, protecting species that have disappeared from the surrounding countryside. The study argues that these sites should be formally recognized as priority areas for national conservation efforts. The traditional practices that have protected these forests for centuries are proving to be a powerful tool for saving biodiversity. By supporting these local management systems and filling in the gaps with new surveys in areas that have not yet been studied, Ethiopia can ensure that these green islands continue to serve as a refuge for its unique natural heritage.