Emergy synthesis of dry afromontane forest ecosystem services in Tigray, Ethiopia

Abstract Dry forests play a significant role in carbon sequestration and storage, biodiversity conservation and soil moisture regulation. The indirect ecosystem services provided by the forests are often undervalued due to the lack of a proper valuation system. Traditionally, the economic valuation of forests has primarily focused on direct use values, which only represent a fraction of the real value of forest ecosystem services. This study aims to assess the values of woody species diversity, carbon stock, and soil moisture using emergy valuation method. In addition, it seeks to evaluate forest sustainability and compare emergy based values among the different forest types in Hugumbirda dry Afromontane Forest in Tigray, Ethiopia. The forest was stratified into Mixed Natural Forest (MNF), Mixed Plantation (MP), Juniperus procera Plantation (JP), and Cupressus lusitanica Plantation (CP) forest types. Then, data on woody species diversity and carbon stock estimation were collected from 60 randomly selected 20 m * 20 m plots. A total of 300 soil samples were collected from these plots for soil moisture content determination. Woody species richness was calculated using diversity indices, and carbon stock was estimated using an allometric equation specifically developed for dry Afromontane forests in the study region. Sustainability was assessed using emergy indices and ratios. The results showed significant differences ( P  < 0.05) in carbon stock, soil moisture content, and species richness emergy among the forest types. The MP forest type showed a significantly higher ( P  < 0.05) emergy of carbon stock compared to the other forest types. The MNF showed significantly higher ( P  < 0.05) emergy of moisture content than the MP and CP forest types. The emergy of species richness, cumulative emergy, and emdollars of the MNF were significantly higher than the other three forest types ( P  < 0.05). These findings highlight that MNF type demonstrates better tree species richness, indicating strong potential for their sustainability and ecological resilience. Therefore, conserving mixed natural forests is recommended to enhance biodiversity, ecosystem resilience, and sustainable resource value for long-term environmental and community benefits.