Runoff and sediment characteristics of forestland with Panax notoginseng cultivation under natural rainfall conditions
[Background]Soil and water loss is a major issue affecting the ecological environment of our country.The planting of Panax notoginseng(PNS)is a rapidly developing new planting pattern.However,most of the current studies are aimed at improving the yield and quality of PNS.The effects on runoff,sediment yield are rarely assessed,and the effect mechanism are still unclear.[Methods]The present study was carried out at the forestland with PNS cultivation in Xiaodaohe forest farm in Boshang town,Lincang city,Yunnan province as the research area,and taken the natural forest land as the control,forestland with PNS cultivation as the research object.The runoff plots in 5°,15° and 20° were established and the runoff and sediment yield under natural rainfall conditions were observed for the rainfall events during the PNS growing season of 2-year-old and 3-year-old in the rainy season in 2022.Scientific methods were used to collect the samples after the rainfall,and SPSS software was used to analyze the significance and correlation of the data.[Results]1)The runoff and sediment yield from forestland with PNS cultivation increased by 64.48％and 148.56％respectively,compared with natural forest land.The runoff,sediment yield were 43.64％and 34.43％higher in 2-year-old than that in 3-year-old forestland with PNS cultivation.2)The runoff and sediment yield from forestland with PNS cultivation increased with the increasing of slope gradient and showed positive(R2＞0.93)exponential relationships with the slope gradient.3)The runoff,sediment yield correlated significantly with rainfall eigenvalues and there was a linear positive correlation between runoff,sediment yield and rainfall,rainfall erosive(R2＞0.32)in forestland with PNS cultivation.And the runoff,sediment yield significantly positively correlated with forest litters,soil organic matter content,porosity and infiltration rate,but significantly and negatively correlated with soil bulk density.[Conclusions]The PNS cultivation under forest induced a significant increase in the runoff and sediment yield due to alterations in above-ground litter,soil infiltration and soil constructure.However,the maximum sediment yield was only 36.76 t/(km2·a)on the 20° slope of PNS plantation for two years,which was still classified as slight erosion.The sediment yield amount was far lower than the allowable sediment yield amount of 500 t/(km2·a)in the rocky mountain area of southwest China.The results may provide theoretical reference and data support for the sustainable development to understory Chinese medicinal materials plantation.
Panax notoginseng cultivated under forestrunoff and sediment yieldslope gradientrainfall eigenvaluessoil physicochemical properties
万方数据
维普
