古树根境土壤改良及复壮效果评价——以重庆市铜梁区黄葛古树为例

The Evaluation on Soil Improvement and Rejuvenation Effect of the Ancient Trees--Taking Ancient Ficus virens in Tongliang District of Chongqing as an Example

通过拆除硬质铺装和原石板树池,更换根系土壤等复壮保护措施,对重庆市铜梁区龙都路2号院内2株黄葛古树进行复壮保护。为评价古树复壮效果,以光合作用速率、新生梢生长量和叶绿素相对含量(SPAD),并结合树体外部形态变化为评价指标,于2018—2020年进行跟踪调查。结果表明,2株古树生长势有明显改善。复壮后,2株黄葛古树CO2日同化量均呈持续增长趋势,增幅在72.58%~141.87%;2株古树新生梢枝条长度、叶片数量、干物质量、叶面积以及SPAD均显著增加。在跟踪调查期间,叶片未出现提前落叶、枝条干枯等现象,树体生长势趋于正常水平。根际土壤改良是直接有效的古树复壮保护方法,能从根本上改善古树生产效能,提高叶片光合速率、SPAD和新梢生长量等表征生长能力指标,这些指标可对古树复壮效果作出指示性评价。

Two ancient trees of Ficus virens Ait.var.sublanceolata(Miq.)Corner were rejuvenated and protected by removing hard pavement,original slate tree pool and changing root soil.To evaluate the rejuvenation effect of ancient trees,this study took photosynthetic rate,growth of new shoots and relative chlorophyll content(SPAD),and combined with the external morphological changes of trees as evaluation indexes to conduct follow-up investigation from 2018-2020.The results showed that the growth potential of the two ancient trees had been significantly improved.After rejuvenation,the daily CO2 assimilation amount of the two ancient trees showed a trend of continuous increase,ranging from 72.58%to 141.87%.The length of new shoots,the number of leaves,the dry matter mass,the leaf area and SPAD of the two ancient trees increased significantly.During the follow-up investigation,there were no early deciduous leaves or dried branches,and the growth potential of the trees tended to a normal level.Rhizosphere soil improvement is a direct and effective method for rejuvenation of ancient trees.It can fundamentally improve the production efficiency of ancient trees,improve the photosynthetic rate of leaves,relative content of chlorophyll and growth of new shoots,which can make an indicative evaluation for the rejuvenation effect of ancient trees.