杭州湖滨景区古樟树不同立地土壤性状分析

Soil properties of ancient Cinnamomum camphora at different sites in the lakeside scenic area of Hangzhou

针对湖滨景区立地环境地下水位高,人为干扰大等特点,对古樟树Cinnamomum camphora树冠投影下的土壤进行理化性质及养分的测定。结果表明:古樟树生长地土壤pH 6.57～7.58,略偏碱性;土壤容重为0.75～1.28g·cm-3,土质较为疏松;土壤有机质为16.1～78.8 g·kg-1,养分属于中等偏上水平。土壤的全氮、全磷、全钾、碱解氮、速效磷、速效钾之间呈显著正相关(P<0.05),与交换性钙、交换性镁呈负相关,与微量元素之间的相关性不显著。三潭绿地的土壤性状优于环湖绿地、草坪、树池中的土壤性状,更利于古樟树的生长;用陶粒、树皮作为覆盖的树池,其土壤性状优于用草皮覆盖的树池土壤,但生长于树池中的古樟树人为干扰系数大,变异系数大于用草皮覆盖的树池。其中,pH值偏高可能对古樟树的生长造成一定的影响。因此,优先选择树皮、木片等有机覆盖物覆盖树池,避免在树冠投影线范围内铺设草皮和播草籽,减少景区改造后混杂在土壤中的水泥、石灰、砖块等碱性物质,有利于平衡土壤酸碱度,提高土壤的通气、保水和保肥性。

Soil physical and chemical properties as well as nutrient contents under ancient Cinnamomum camphora crown projections were studied at the lakeside scenic area of Hangzhou,where a high water table and strong human disturbance were found,using a correlation analysis.Results showed that soil pH was partially alkaline varying from 6.57 to 7.58;soil bulk density was loose varying from 0.75 to 1.28 g·cm-3;organic matter content varied from 16.1 to 78.8 g·kg-1;and overall the soil nutrient levels were above average.A strong positive correlation（P0.05） among soil total N,total P,total K,hydrolysable N,and available P were found.Additionally,a negative correlation was found between soil exchangeable Ca and exchangeable Mg（P0.05）,but there was no correlation among different microelements.Soil properties in the green space of the Three Pools Mirroring the Moon Scenic Area were superior to the green space,lawn,and tree ponds at Round Lake which was more beneficial to the growth of ancient C.camphora trees.In tree ponds,soil properties with ceramic and bark mulch were superior to turf grass or seeded grass as mulch;however,the human activities that readily disturbed ancient C.camphora growing in tree ponds meant that the coefficient of variation with ceramic and bark mulch was higher than with grass mulch.The higher pH would be harmful to the growth of Cinnamomum camphora.Therefore,the balance of soil pH,aeration,water and fertilizer conservation will be improved by covering the tree pool with organic mulch such as bark and wood chips,avoiding laying sod and seeding within the projection region of the crown,and reducing the alkaline substances such as soil cement,lime and bricks mixed in the soil after the transformation in the scenic spots.