A carbon-sink in a sacred forest: Biologically-driven calcite formation in highly weathered soils in Northern Togo (West Africa)

Soil organic matter (OM) is a source of fertility for food provisioning and means climate mitigation. A high pedodiversity observed over very short distances due to both past present land use, such as in Western Africa (Northern Togo), makes this crucial issue. In particular, some small spots covered by sacred forests (forêts sacrées) cultural value area are extremely biodiverse, calcareous OM contrast with the non-calcareous, poor OM, overgrazed woody savannah agricultural surroundings. The objectives our work were understand process CaCO3 formation soil under highly biodiverse forest using morphological, micromorphological, chemical mineralogical analyses. results show degree weathering gneiss parent material, presence plinthite gravels, dominance 1:1 clays, swelling clays imperfectly drained soils, low content. palygorskite, although traces, suggests drier intervals consistent context extreme wet dry conditions region. rich soils forest, bio-calcification takes place form needles, micrite hypocoatings around biopores calcified cells. Oribatid excrements associated calcite soil, indicating that litter recycling has played an important role calcite. We hypothesize biological activity releasing CO2, HCO3– precipitation Ca2+ released recycled plagioclases, lead different forms secondary calcium carbonate soils. oxalate content vegetation formation, possibly via oxalate-carbonate pathway, may also have these material not calcareous, meaning lithogenic carbonates, thus making them carbon sink. characteristics indicate potential development yields sequestration relevant global change policies.