Potato (Solanum tuberosum) is an indispensable commodity, mainly cultivated by high-altitude mountain households, that sustains and supports the livelihood of an overwhelming 51% of the Bhutanese population. The popularity of potato cultivation among Bhutanese farmers can be attributed to the crop’s adaptability to a wide range of agroclimatic conditions such as a rainfed crop, high productivity, an assured market, and a reliable source of income for the farming families. We hypothesize that the changing climate would make the livelihood associated with potato cultivation in Bhutan more vulnerable. We tested this hypothesis to identify the sources of vulnerability of smallholder farming households using the Livelihood Vulnerability Index (LVI) and LVI-IPCC (Intergovernmental Panel on Climate Change) approaches in six potato growing districts of Bhutan: Bumthang, Chukha, Gasa, Mongar, Tashigang, and Wangdue. Primary data were generated through a semi structured sample survey of 240 households on the seven major livelihood components of sociodemographic profiles, livelihood strategies, social networks, health, food, water, natural disasters, and climate variability. The results showed that the LVI (range 0.302 to 0.375) and LVI-IPCC (range −0.005 to 0.030) differed significantly (p < 0.001) across the districts. The districts of Tashigang and Mongar were less vulnerable than the other four districts by the LVI approach, whereas Bumthang was also revealed to be less vulnerable using the LVI-IPCC approach. The degree of vulnerability in a district differed according to their level of exposure and adaptive capacity to the climate change impacts of the potato farming household. The results are expected to serve as empirical evidence for designing a future course of actions to mitigate the negative impacts.

Purpose: Earthworms play a critical role in soil ecosystem functions through the cycling of organic matter and nutrients. However, some land uses or environmental conditions are more favorable habitats for them than others. Thus, the objectives of this study were to evaluate the prevalence of earthworm density and its relationship to land uses and soil properties. Methods: The study was conducted in three districts (Wangdue Phodrang, Chhukha and Dagana) in Bhutan in three land uses (organic fields - OrgF, conventional fields - ConF and natural vegetation - NatV) under three altitudes (high-, mid- and low-altitudes) and three soil depths. Results: Overall, earthworm density at high-altitude was significantly (P < 0.001) higher than that at mid- and low-altitude sites. Further, across altitudes and soil depths, OrgF sites had a significantly (P < 0.001) higher earthworm density (120 earthworms m^− 2) compared to that in the NatV (56 earthworms m^− 2) and ConF (43 earthworms m^− 2) sites, and the density decreased significantly (P < 0.001) and successively with the increase in soil depth. The coefficient of determination (R² ≥ 0.51; P < 0.001) showed a positive and moderate relationship between the earthworm density with soil organic C and total N in OrgF sites, but the relationship was weak (R² ≤ 0.22) in the ConF or none in the NatV sites. Conclusions: Substituting chemical fertilizers with organic manures could increase earthworm density by enhancing soil health through the cycling of organic materials and nutrients in the soil. The findings demonstrate empirical evidence for earthworm prevalence in different land use types across altitudinal gradients and provide valuable decision-making insights to land users and policymakers alike.