求翻译：本文以土壤容量及孔隙度俄日土壤压实指标，以南京市绿化树种香樟、红叶石楠和白玉兰幼苗为材料，通过模拟土壤压实，探讨土壤压实对幼苗水利结构特征的影响，探讨对水分吸收、运输策略及其机理，为选择耐土壤压实的城市绿化树种提供理论依据。是什么意思？

This capacity of soil and soil compaction indexes in porosity between Russia and Japan, Nanjing greening tree species cinnamomum camphora, photinia and seedlings of Michelia Alba for the material, by simulating soil compaction, discussion on effect of compaction on soil structure characteristics of seedlings water, moisture absorption, transport policy and mechanism discussion on, for select urban afforestation tree species to provide theoretical basis of soil compaction resistance.