Characteristics of soil erosion of different plant communities converted from slope cropland in the hilly-gully region of the Loess Plateau
[Background]The severe condition of soil and water loss in the Loess Plateau has resulted in critical agricultural and environmental problems.Vegetation restoration plays an essential role in controlling the soil erosion in the Loess Plateau.Yet there were few researches on analyzing the characteristics of soil erosion of different plant communities converted from slope cropland in the region.[Methods] The research was conducted between 2012 and 2015.Based on the succession of local plants,10 plant communities on abandoned slope croplands in 4 watersheds of Ansai County were selected and were classified in 4 groups:naturally restored herbage community (Artemisia scoparia,Stipa bungeana,Bothriochloa ischaemun,Artemisia gmelinii,and Artemisia giraldii),naturally restored shrub community (Sophora viciifolia),artificially established shrub community (Caragana intermedia and Hippophae rhamnoides) and artificially established arbor community (Robinia psendoacacia and Populus simonii).Totally 45 plots were selected and in each of these communities 3-6 plots were selected,in each plot 3 quadrats were placed as repetition.Annual soil erosion intensity was monitored by erosion pins placed in these plots.Characteristics of soil erosion of different plant communities were analyzed with ANOVA,combined with the hydrologic years divided by the characteristics of rainfall.Gray theory was used to determine the influence of potential indices caused soil erosion.[Results] Rainfall in research area was distributed unevenly,and rainfall erosivity was the driver factor causing the differences of soil erosion intensity of plant communities in different years.The ability of controlling soil erosion depended on the species of plant community:naturally restored shrub community (1 285.36 t/km2) ＞ naturally restored herbage community (2 152.65 t/km2) ＞ artificially established shrub community (2 320.50 t/km2) ＞ artificially established arbor community(2 661.14 t/km2).The soil erosion intensity of Robinia psendoacacia was the largest (3 875.02 t/km2) among these plant communities.Gray correlation analysis revealed that the rainfall and slope gradient had more impact on soil erosion than coverage in all communities.In shrub and arbor communities,the effect of slope gradient ＞ rainfall,but in herbage communities,rainfall ＞ slope gradient.When mentioned coverage,in natural restored community,cover of litters ＞ vegetation cover;and in artificially established community,vegetation cover ＞ cover of litters.[Conclusions] Under current status of vegetation,effects of precipitation on soil erosion reduced effectively in undisturbed plant communities.Natural vegetation should be restored initially with trees and shrubs introduced by human at proper time and place.Meanwhile,the undergrowth vegetation and litters in forest communities should be promoted earlier and protected,meanwhile human disturbances should be reduced as more as possible.
soil erosionplant communitieserosion pingrey correlation analysishilly-gully loess region
国家科技期刊平台
NSTL
万方数据
维普
