硬覆盖对城市街路行道树土壤呼吸的影响

【作者】 邹丽敏；

【导师】 袁星； 丁蕴铮；

【作者基本信息】 东北师范大学 ， 环境科学， 2004， 硕士

【摘要】 本文应用静态气室法对硬覆盖条件下街路行道树的土壤呼吸进行了测定，研究了硬覆盖对行道树立地土壤的理化性质、土壤温度和微生物含量的改变，及对土壤呼吸带来的影响。结果表明：街路硬覆盖的铺设使街路行道树立地土壤的层次和结构发生变化、容重加大、孔隙变少、有机质含量变低，但对N，P，K含量影响不大；硬覆盖使其下的土壤微生物含量减少，降低了微生物对土壤中营养物质的生物化学转化过程，进而危及树木所需多种营养物质的供应；硬覆盖能使相同气候条件下的土壤温度变高，在夏季形成对地表根系和树干的高温灼烧，秋季突然降温时，由于巨大的温差使得植物细胞无法适应，形成胞间和胞内结冰，造成细胞膜的破裂，进而死亡；硬覆盖能在大气和土壤间形成气体交换屏障，使土壤呼吸产生的大量CO2积聚在硬覆盖层以下，使街路行道树长期生长在高浓度CO2的土壤中，胁迫根系进行厌氧呼吸，终产物（乳酸，主要是乙醇）将导致根系生长停止，使耗能的离子运输受阻，根系的透水性下降，进而使透过受伤（垂死）根系的溶液质流紊乱，最终导致树木的死亡。根据研究结果提出了改善街路树立地土壤环境的建议：在街路铺设时，尽量减少硬覆盖，加大裸地面积，给每株行道树留下足够其生长需要的土壤空间；在条件允许情况下，将硬覆盖改成<WP=4>透气铺装或软覆盖；必要时在地下埋设通气管道，安装透气井等装置；合理改良土壤、补充水分和养分，为行道树正常生长建立良好的土壤条件。更多还原

【Abstract】 The respiration of the crust－covered soil under the trees along the People’s Street in Changchun city was measured using captive test in this paper. The chemical and physics qualities, temperature, the changing of microbes’ content of the crust covered soil and the influence to the respiration of the soil were studied. The result showed as following：The arrangement and the structure of the soil were changed by the crust－covered paving. It made the capacity of soil bigger， the hole smaller and the organic materials less，however it had little influence on the content of the N，P，K in the soil. The content of the microbes in the soil was decreased and the process of the translation between the biology and chemistry of nutriments was hindered by the crust－covered paving. It is very harmful for the providing of the nutriments to the trees growing.The crust－covered paving would lead to the higher temperature of the soil under the same conditions and burn the root in the surface layer and stock when under the summer high temperature. Plant cells could not adapt to the great temperature change for the freezing between the cells and in the cells which would lead to the break of cell membrane and in the end lead to the death of the trees when the autumn is coming.The air exchange between the air and the soil would be hindered by the crust－covered paving. It increased the concentration of CO2 in the soil. With the stress of high concentration of CO2 for a long time， the roots had to respire under anaerobic condition. Ultimate products （lactic acid, mainly ethanol）would prevent the growth of the roots and the transit of the consume iron. The infiltration of the roots would <WP=6>decrease and finally，the trees would die. The improvement methods to the soil conditions under the crust－covered paving were put forward as following：The area of the crust－covered soil should be decreased and the area of the uncovered soil should be increased so that there is enough soil capacity for the trees’ growing. If condition permitted, the paving which can make the breath freely or soft covered paving should be used instead of the crust－covered soil. The pipeline or the well to make soil breathe freely should be put under the ground if necessary. The methods of improving the soil conditions and supplying water and nutriment to soil should be adapted in order to improve conditions for the trees growing.更多还原