北京戒台寺古油松生长衰退与土壤条件关系初步研究

该文对潭柘寺风景区戒台寺的部分古油松的土壤条件进行了研究. 研究发现古松周围土壤各层都缺乏有机质、全氮和速效磷；不缺乏速效钾、有效铁、有效铜、有效锌. 土壤的总孔隙度适中，但毛管孔隙度太高，而非毛管孔隙度太低，多为1.1%～6.4%，小于10%的最低限. 土壤的表层水分含量偏高达25%，超出其适宜范围15%～17%，易造成古树烂根；土壤的渗水性能较低，不利于排水. 土壤各层均为碱性，不利于古树生长；土壤表层钠离子含量大于100 mg/kg，对古树根系生长有毒害作用；土壤的还原性物质总量在表层0～34 cm以下较高，大于1.5%，不利于古树根系通气. 建议科学监测古树生长环境以及调查研究土壤理化性质、土壤水分变化、机械损伤程度和环境污染物的积累等诸因素，并控制在允许的指标内. 

Relationship between soil conditions and declining growth rate of aged Pinus tabulaeformis at Jietai Temple of Beijing.

The relationship between soil conditions and the low growth rate of famous aged Pinus tabulaeformis in Jietai Temple was studied. Results showed that these famous aged pine trees grew on soils containing low organic matter, total nitrogen and readily available phosphorus but with enough available potassium, iron, copper and zinc. A suitable total soil porosity but with high capillary porosity and very low non-capillary porosity of 1.1%--6.4% was found for tree growth. High soil moisture in topsoil (25%) along with a very low permeability may lead to oxygen shortage in the roots. Soil pH was higher than 8 in all layers. In topsoil, water-soluble sodium was higher than 100 mg/kg which may be toxic to the pine trees, and easily reducible materials were higher than 1.5% which may put the roots in a reduction condition. Suggestion was made to scientifically monitor the habit of the old pine trees and to investigate the chemical and physical properties of soil, soil moisture, mechanical harm and environmental pollutants so as to control them in the suitable ranges.