Miombo conversion to monoculture tree plantations: Changes in soil properties

Abstract

Monoculture plantations replacing native woodlands are increasingly common globally. In Mozambique, vast miombo* woodlands have been replaced by single‐species plantations. Studies on the effect of replacing native woodlands by single‐species tree plantations on soil properties are abundant; however, those focused specifically on the replacement of miombo and considering a longer time since replacement and covering different growth stages are scarce. This article aimed at assessing the effects of the conversion of miombo to monoculture on soil properties and studying the effect of species planted, plantation age, and rotation on soil capacity to store carbon (C) and nitrogen (N). Plantations established in soils formerly covered by miombo were compared to the remaining original miombo with regard to soil properties. The effect of species planted, plantation age, and rotation on soil properties was examined using the three‐way ANOVA, followed by Tukey's test. Miombo conversion to plantations led to an increase of up to 66% of soil organic C (SOC) and 77% of total N (STN) and a decrease in soil bulk density (BD) of up to 16%. The replacement of the first‐ by second‐rotation plantations led to a decrease of up to 38% in SOC and STN and an increase of up to 32% in BD. BD decreased with plantation age; SOC and STN stocks tended to increase: 60 years after the replacement of miombo by plantations, SOC and STN increased by up to 88%. Changes in soil properties due to the replacement of miombo by monoculture were mainly driven by the species planted. * a sparse open deciduous woodland characteristic of dry parts of eastern Africa