Soil erosion and water retention varies with plantation type and age

Soil erosion control and water retention is a major ecological function of plantations and may be affected by both plantation type and age. In this study, we investigated both surface runoff and sediment load under different plantations in southern China for six years (2008-2013) in order to illustrate the influence of plantation type and age on water retention and soil erosion. Our results showed that mature plantations functioned better than young plantations in terms of soil erosion control and runoff reduction, which reduced runoff and soil erosion by 64.5 ± 6.2% and 72.2 ± 7.9% more than young plantations, respectively. Our study indicated that plantations play a beneficial role in controlling soil erosion and reducing water loss, and this effect is more pronounced with plantation age. Both runoff coefficient and sediment load were least under Eucalyptus spp. either in young or mature plantations, suggesting that Eucalyptus spp. is better adapted for water retention and soil conservation compared to other plant species. Correlation analysis showed that herb species and herb Margalef index were the top two factors affecting the surface runoff and sediment load in young plantations but litter storage and tree Shannon index were the top two affecting factors in mature plantations. This shift was consistent with the decreasing trend of herbs and increasing trend of litter storage with the time of vegetation restoration.