A field campaign was conducted from July 2021-July 2022 in Thetford Forest to collect data on nitrogen cycling processes in a chronosequence of plots in the conifer-to-broadleaf conversion process, including: mature pine, recently felled sites, sites planted 0-2 years ago, planted 5-8 years ago, planted 10-13 years ago, mature broadleaf. Soil solution and throughfall chemistry+volume was measured monthly, in situ nitrification was measured between July-August 2021, soil carbon and nitrogen stocks were measured in July 2021. Soil pH, bulk density and organic layer thickness were measured in 2022. Site names align with the stands detailed in the Forestry Commission's subcompartment database.