Different types of trees affect how much carbon is stored in the soil depending on the soil's age and previous use. Coniferous trees store more carbon in older forest soils, while broadleaf trees store more carbon in younger post-mining soils. In agricultural soils, both types of trees store similar amounts of carbon. The pH and clay content of the soil also play a role in carbon storage. In soils with high pH, more carbon is stored under broadleaf trees. In post-mining soils, carbon storage is lower when the leaf litter has a high carbon to nitrogen ratio. Overall, the type of tree and soil characteristics influence how much carbon is stored in the soil during reforestation and afforestation efforts.