Impacts of household wealth status on woody species diversity and biomass carbon stocks in parkland agroforestry system of Northwestern Ethiopia

Parkland agroforestry has a long history in Ethiopia and supports sustainability, but there is little empirical data on how socioeconomic factors influence carbon stocks of scattered trees. This study assessed how wealth status affected woody species diversity and biomass carbon stock in northwestern Ethiopia. A multistage sampling procedure was used: the district was purposively selected for its well-established parkland agroforestry and high on-farm tree density, followed by random selection of two kebeles and simple random sampling of households, which were then classified into wealth categories based on wealth classification criteria. Tree biomass was assessed within 50 m × 100 m quadrats, and species diversity was calculated with the Shannon–Wiener index. Biomass and carbon stocks were estimated using allometric equations. Data were analyzed using one-way ANOVA, Tukey’s HSD test, and Pearson correlation analysis at p < 0.05. The result showed that species diversity differed by wealth class, with the highest H′ values (1.55 and 1.54) in rich households and the lowest (1.00 and 0.88) in poor households in sites 1 and 2, respectively. Biomass carbon stocks also varied, with rich households showing the highest biomass (16.57 and 19.18 t ha⁻¹) and carbon stock (8.28 and 9.59 t ha⁻¹), while poor households had the lowest. Pearson correlationanalysis revealed strong positive relationships between wealth rank and Shannon diversity ( r = 0.881, p < 0.05), above-ground carbon ( r = 0.885, p < 0.05), below-ground carbon ( r = 0.874, p < 0.05), and total biomass carbon stock ( r = 0.891, p < 0.05). Shannon diversity was also strongly correlated with above-ground carbon ( r = 0.959, p < 0.01), below-ground carbon ( r = 0.954, p < 0.01), and total biomass carbon stock r = 0.962, p < 0.01). The observed disparities likely reflect differences in landholding size, tree density, and tree size structure among household wealth categories rather than wealth status alone. Wealth status significantly influences biomass and carbon stock. Supporting lower-income households with resources and technical assistance can enhance tree density and carbon sequestration, promoting equitable and sustainable land use.