Distribution and depth of edge influence on surface soil moisture in field-forest boundary in arid valley of upper reaches of Minjiang River

To study distribution and depth of edge influence on surface soil moisture in field-forest boundary in arid valley of upper reaches of Minjiang River, typical pepper-forest boundary was selected in arid valley of upper reaches of Minjiang River, China. Moisture content in 0-15 cm surface soil was determined with time domain reflecmentory (TDR) during drought and after rain. The aims were to describe soil moisture distribution along transect gradient and the variety in pepper field and forest. And moving split-window techniques (MSWT) was employed to determine the depth of edge influence. The results show: surface soil moisture content was lower and exhibited a high degree of variability along transect gradient. It displayed the change of 'V' figure from forest to boundary and to pepper field, but the fluctuation of 'W' wave in interior forest and interior pepper field. The variability of moisture content was less between days during drought, but it descended after rain day by day. The depth of edge influence on moisture content was 14 m and 8 m after rain and during drought, respectively.