Accumulation of SOC in relatively undisturbed tropical mountain foothills under climate change scenarios: The case of Uluguru Mountain, Tanzania

Soil nutrients form an important part of agro-ecosystems in various landscapes, including mountainous areas. Most foothills in tropical mountains are heterogeneous in terms of the accumulation of soil nutrients due climatic location and ecological endowments. Since most mountain foothills have potential for the provision of environmental services, it is imperative to assess the salient soil nutrients including carbon in order to determine the amount. This study assessed the accumulation of soil organic carbon (SOC) in the relatively undisturbed foothills of Uluguru Mountains whose geology indicates that they were formed during cretaceous age (i.e. ≈50 million years ago). The study also determined the trends of rainfall and temperature because these elements of climate have important influence on carbon accumulation. In conducting this study, we sampled Kiroka Village (in Kiroka Ward) because it is found at the foothills of the Uluguru Mountain and most of its parts are relatively undisturbed. In this place, sixteen soil sampling points were established within one hectare and these points involved two soil depths (i.e. 0-20 cm and 20-40 cm) and two locations (i.e. lowland and upland). The Walkley–Black Method was used for SOC analysis while Mann–Kendall Test was employed for climate data analysis. The results exhibit that there have been significant variations in SOC accumulation under the two soil depths and locations. In the lowland areas, SOC was 1.1 and 0.43 MgC ha −1 for the depths 0–20 cm and 20–40, respectively. Besides, in upland areas, SOC was 0.38 and 0.31 MgC ha −1 for the depths 0–20 cm and 20–40, respectively. Most cereal crops require a considerable amount of SOC in the soil that ranges between 0.5 and 2 MgC ha −1 . Additionally, the mean annual rainfall and temperature patterns from 1980 to 2020 declined and intensified at R 2 = 0.15 and 0.19, respectively. Therefore, these results inform environmental experts, climate practitioners and other relevant stakeholders to endorse suitable and sustainable environmental management methods in the mountainous areas.