云南省中部3种森林土壤含水率、容重和细根重及其垂直分布

SOIL MOISTURE CONTENT,BULK DENSITY AND FINE ROOT WEIGHT AS WELL AS THEIR VERTICAL DISTRIBUTION IN SOILS OF THREE FOREST TYPES IN THE CENTRAL YUNNAN PROVINCE

根据27个土壤剖面的405个土壤样品,研究云南中部地区华山松林、旱冬瓜林、云南松林的土壤含水率、容重和细根重及其垂直分布特征.结果表明:3种森林100 cm深土壤的平均含水率分别是(28.79±11.98)％、(24.66 ±9.89)％、(14.11±5.84)％,差异极显著;平均容重分别是(1.14±0.20) g/em3、(1.26±0.18)g/cm3、(1.42±0.12)g/cm3,差异极显著;平均细根重分别为(0.1956±0.2144) g/100 cm3、(0.0706±0.1066)g/100 cm3、(0.1381±0.2989) g/100 cm3,在0.05水平上差异显著.华山松林林下土壤的物理性质最好,旱冬瓜林次之,云南松林最差.3种森林里,随着土壤深度增加,土壤含水率增加,土壤容重和土壤细根重减少.华山松林与云南松林平均容重与平均细根重均显著负相关,旱冬瓜林平均含水率与平均容重显著负相关.华山松林下土壤细根量最大,0 ～ 20 cm层根系占根系总重量的83％.

Based on the 405 soil samples from 27 soil plane surfaces,it was studied the moisture content,soil bulk density,fine root w eight as w ell as their vertical distribution in soils of forests dominated respectively by Pinus armandi,Alnus nepalensis and Pinus yunnanensis. The results indicated that,w ithin 100 cm depth in soils of the three forests,the average moisture content w ere( 28. 79 ± 11. 98) %,( 24. 66 ± 9. 89) %,( 14. 11 ±5. 84) %,respectively; the average soil bulk density w ere( 1. 14 ± 0. 20) g / cm3,( 1. 26 ± 0. 18) g /cm3,( 1. 42 ± 0. 12) g /cm3respectively; and the average fine root w eight w ere( 0. 1956 ± 0. 2144) g /100 cm3,( 0. 0706 ±0. 1066) g /100cm3,( 0. 1381 ± 0. 2989) g /100 cm3,respectively. Soil moisture content increased w hile soil bulk density and fine root w eight decreased from the surface to depth of soils in the 3 studied forests. The best physical properties of soil is Pinus armandi,the second is Alnus nepalensis and the w orst is Pinus yunnanensis. It w as also found the negative correlations of soil bulk density and soil fine root w eight of Pinus yunnanensis forests and Pinus armandi forests,and the negative correlations of soil moisture content and soil bulk density in Alnus nepalensis forests. Eighty three percent of soil fine root w ere found in the 0- 20 cm surface soils of Pinus armandi forests.