Soil water infiltration in Pinus tabuliformis plantation in the Ziwuling

MA Wenchang; SUN Yubo; LIN Fei; LUO Chengjiang; WANG Dengjie; QIAO Bin

doi:10.13522/j.cnki.ggps.2024399

Abstract：[Objective]Soil water infiltration is critical for moisture retention,vegetation growth and long-term ecosystem stability,particularly in ecologically fragile areas like the Loess Plateau.Pinus tabuliformis is a key species used in regional reforestation and plays a vital role in soil hydrological processes.This paper investigates soil water infiltration in P.tabuliformis plantations with different stand densities in the Ziwuling region of the Loess Plateau.[Method]Field experiments were conducted in August 2023 at the Lianjiabian Forest Farm,Heshui County,Gansu Province.Five stand densities,2 222,3 200,4 802,6 250 and 7 503 plants/hm2,were selected.Soil water infiltration in each stand was measured using the double-ring infiltrometer method.Five models were evaluated for their ability to simulate water infiltration:the General Infiltration Model,the Jiang Dingsheng Model,the Horton Model,the Philip Model,and the Kostiakov Model.[Result]① With increasing stand density,the initial infiltration rate,steady infiltration rate,average infiltration rate and cumulative infiltration showed unimodal trends,all peaking at stand density of 4 802 plants/hm2;their corresponding average values were 18.27 mm/min,11.31 mm/min,13.57 mm/min,and 143.45 cm,respectively.② Cumulative infiltration under different stand density ranked(from high to low)in the order of 4 802＞6 250＞7 503＞3 200＞2 222 plants/hm2.③ Overall,soil infiltration capacity,based on all indicators,ranked with stand density in the order of 4 802＞6 250＞3 200＞7 503＞2 222 plants/hm2.④ The R2 value of the general infiltration model,the Jiang Dingsheng model,the Horton model,the Philip model and the Kostiakov model was 0.985,0.966,0.951,0.867 and 0.760,respectively.[Conclusion]Among all stand densities of Pinus tabuliformis plantations,the density 4 802 plants/hm2 had the highest water infiltration capacity,showing superior water conservation potential.The general infiltration model proved to be the most suitable for simulating soil water infiltration processes in this region.