Effects of stand density on biomass and soil physico-chemical properties of Pinus tabuliformis forest in the loess area of western Shanxi
[Objective]This study is in order to explore the effects of stand density on biomass and soil physicochemical properties in Pinus tabuliformis forests,for high-quality development and performance of the ecological service function.[Method]A 30-year-old P.tabuliformis forest in Caijiachuan watershed,Jixian County,Shanxi Province,was used as the research object,and the standard wood method was used to measure the biomass of individual plants and the overall biomass of the sample plots under the conditions of different densities,and the soil physicochemical properties were determined,so as to analyze the effects of stand density on the biomass of P.tabuliformis forest and soil physicochemical properties,and to determine their relationship by redundancy analysis(RDA)and Spearman's correlation analysis.[Result](1)The differences in stand biomass and total tree biomass between different densities were significant(P＜0.05),and with the increase of stand density,stand biomass gradually decreased,and the total tree biomass had a peak at a density of 1 750 plants·hm-2;(2)The physicochemical properties of soil in forests of different densities differed significantly(P＜0.05),with soil porosity being the highest at 1 750 plants·hm-2,reaching 52.38％,soil moisture content being the highest at 2 750 plants·hm-2,reaching 13.84％,and soil fertility being the best at a density of 1 750 plants hm-2;(3)RDA and Spearman's correlation analyses revealed that total soil porosity,organic carbon and quick-acting phosphorus were all highly significantly correlated with arbor biomass in the sample plots(P＜0.01),and below-ground biomass was significantly affected by soil water content(P＜0.05).[Conclusion]The stand density should be maintained at 1750 plants·hm-2 for the purpose of sequestering carbon and releasing oxygen and maintaining maximum productivity,and for the purpose of increasing the carbon sink capacity of the soil and improving fertility,and at 1 750-2 750 plants·hm-2 for the purpose of retaining soil and water and improving soil water retention properties.[Ch,4 fig.5 tab.40 ref.]
万方数据
维普
