Current status of tree species diversity at Abu Gadaf Natural Forest Reserve, Blue Nile Region – Sudan

Tree species diversity and distribution in forests, agroforests and other land uses have been continuously providing food and food-associated materials, medicinal, and livestock fodder, as well as multiple ecological services to human beings. However, unsustainable utilization of forest resources coupled with biotic and abiotic disturbances interrupt forest resources sustainability and ecological processes. A study was conducted in Abu Gadaf Natural Forest Reserve (AGNFR) in 2018 to assess the current status of tree species diversity and use, by surveying 554 sample circular plots (each having 35.7 m radius) with 0.5% sampling intensity distributed systematically throughout the reserve. We found a total of 32 tree species in the AGNFR that belonged to 16 families. The highest tree species frequency, occurrences and density recorded by Combretum hartmannianum followed by Lannea fruticosa and Anogeissus leiocarpus respectively. The highest Importance Value Index (IVI) was recorded by Combretum hartmannianum (51.28). The highest DBH of trees were reported in the range of 10–19.9 cm followed by 20–29.9 cm, additionally the Shannon diversity index and Simpson dominance index were 1.01 and 0.14, respectively and density was 48 tree/ha. Majority of the tree species was found unsustainably harvested affecting their regeneration potential. Different kinds of anthropogenic disturbances including forest fires were rampant in the reserve causing dwindling tree diversity. The study provides baseline information on tree species diversity, and distribution pattern for effective management and conservation of the forest reserve. A preservation action plan may be needed immediately to protect the vulnerable species, particularly those with high ecosystem service value. © The Author(s) under exclusive licence to Society for Plant Research 2024.