Alculate nep before the outbreak and identify the most appropriate conclusion about whether the forest was a carbon sink or a carbon source. calculate nep before the outbreak and identify the most appropriate conclusion about whether the forest was a carbon sink or a carbon source. before the outbreak, the forest was a carbon sink because nep was less than 0. before the outbreak, the forest was a carbon sink because nep was greater than 0. before the outbreak, the forest was a carbon source because nep was less than 0. before the outbreak, the forest was a carbon source because nep was greater than 0.