杨树低产林成因及对策--以宿州市埇桥区祁县镇为例

Causes for Low-production Poplar Plantations and Coping Strategies --A Case Study of the Plantations in Qixian Township, Yongqiao District of Suzhou City

通过设立固定标准地对杨树的中幼林龄期和近熟林龄期生长情况进行调查分析，了解踊桥区祁县镇不同立地条件下杨树长势，判断林分立地条件对生长量影响的关键因子，并进行了标准地土壤剖面结构、理化性质和土壤养分含量对比，结论如下：影响杨树生长的关键因素是林地土层厚度，分析了杨树低产林形成原因是：土壤层浅、瘠薄、空隙度小、质地粘重。并提出相应对策：杨树低产林改造；加强中幼林抚育、进行土壤改良；发展林下经济改善土壤结构理化性质；营造复层林、间接改良土壤，提高林地综合利用率。

In this paper the growth situations of young, middle-aged and near-mature poplar plantations in the fixed sample plots were surveyed and analyzed in order to find out the poplar growth in different site conditions in Qixian Township, Yongqiao District, identify the key factors in site conditions that affect the stand growth. Contrastive analysis was made on the profile structures, physicochemical properties and nutrient contents of the soil in the sample plots. The conclusions were as follows： The key factor affecting the poplar growth was soil thickness. The causes for low-production poplar plantations were thin soil layer, infertility, low porosity and heavy texture of soil. The coping strategies include improving low-production poplar plantations, intensifying tending of young and middle-aged poplar plantations, improving soil, developing under-forest economy（under-forest growing and raising）, improving soil structures and physicochemical properties, improving soil indirectly by growing multi-storied poplar plantations （with lower, middle and upper canopies） and improving comprehensive forestland use efficiency.