Agroforestry practices for woody species diversity and woody biomass carbon stock enhancement in northwestern Tigray, Ethiopia

Agroforestry plays an indispensable role in biodiversity conservation and ecosystem services. However, research on the ecological roles of different agroforestry practices in northwestern Tigray remains limited. This study to investigate the role of three agroforestry practices: homestead, parkland and woodlot in enhancing biodiversity and woody biomass carbon stock. A total of 68 sample plots representing 37 plots of parkland, 25 homestead, and 6 woodlots, were established from the purposively selected sites and households. 38 woody species from 22 families and 36 genera were recorded. Among these species, 26% were recorded in homestead, while 36.8% shared between homestead and parkland, and 18.4% across all land use types. Indigenous species accounted for 57.9%, with exotics represented 36.84% and invasive species 5.26%. The highest species diversity was found in homestead (H' = 1.36), with significant variation among agroforestry types (p = 0.011). The total woody biomass were 32.36 ± 5.26, 17.74 ± 7.71 and 4.62 ± 0.76 Mg C ha–1 in homestead, woodlot and parkland agroforestry respectively. Cordia africana and Faidherbia albida and Ziziphus spina -christi were dominant in homestead and parkland agroforestry land use, whereas Eucalyptus camaldulensis and Acacia lahai dominated in the woodlots. Population structure analysis revealed low seedling regeneration in parklands due to agricultural disturbances. Woodlots in the study area are mostly established in productive farmlands thereby increasing competition with food production. Despite the competition of woodlots with agricultural crops for the productive lands, the findings generally indicate that homestead agroforestry is effective in enhancing ecological sustainability and mitigate climate change impacts. Thus, promoting agroforestry and proper woodlot establishment through engaging communities are essential for fostering community well-being and ensuring sustainable conservation of biodiversity.