机械运输对伊朗北部山林陡峭集材道土壤的干扰(英文)

调查了集材道坡度和运输量对2个土层(0-10和10-20cm)干扰。试验共设置4个运输水平(2,7,12和20次)、2个坡度(<20%和>20%)和2个土层深度(0-10和10-20cm)。结果表明,集材机运输、纵向坡度和土壤深度对集材道土壤容重都有显著影响。不同运输水平与对照条件下的土壤容重存在显著差异。不同坡度、不同土壤深度的平均土壤容积密度随着运输水平增加而显著增加,运输量为12次时土壤容积密度最大,但当运输量在12～20次之间时,土壤容积密度没有显著差异。交通运输与土壤深度之间存在显著的相互作用(F0.05,3=0.109,p<0.001)。不同交通运输条件下,2个坡度的集材道土壤含水量以及2个土壤深度的土壤含水量之间均存在显著差异p<0.001)。虽然集材机运输和坡度都会影响土壤水分含量,但是,两者之间并没有显著相互作用。

Effect of Compaction on Physical and Micromorphological Properties of Forest Soils

The objective of this research was to assess the effect of skidding machinery on soil physical and micromorphological properties. The different positions (control or non-traffic areas, left wheel track, right wheel track and log track) and two soil depths (0 - 10 and 10 - 20 cm) in three repetitions were investigated. The results showed that average soil dry bulk density in four positions and two soil depths were significantly different. Comparison of average total porosity percentage and soil saturated hydraulic conductivity revealed that there were significant differences in four positions and two soil depths. Soil thin section studies using Image Tool software showed that in compacted samples there was an increase in the number of vughs voids and channels voids were in low occurrence. Micromorphological studies showed that soil compaction caused void size to decrease. In compacted samples voids bigger than 10 μm were very rare and dominant voids size was 2 μm. In compacted samples soil structure were damaged and aggregates were compressed. Also soil matrix was compressed and microstructure was massive. Results from this study confirmed that skidding machinery had a significant effect on soil physical and morphological properties. These changes causes soil and environmental degradation due to reduction in water infiltration increasing soil erosion risk.