Abstract:The dynamics of bio\|available nitrogen in soils of pine\|broadleaf mixed forest in Dinghushan Biosphere Reserve were studied using the ion exchange resin bag method.The total available nitrogen (NO\-3\+-\|N+NH\-4\+-\|N) in different seasons ranged from 18.87 to 93.20μg/d·g dry resin and showed significantly seasonal variation depending on different components of available nitrogen and at different depth of soil.It was the highest in the spring season.The available nitrogen in soil was mostly composed of am...