花江喀斯特峡谷适生植物的抗旱特征 Ⅰ:顶坛花椒根系与土壤环境

以15株顶坛花椒作样本进行研究,对其根系的根深、根幅、根的直径、侧根的分布范围、叶重、吸收根的密度及重量等进行实地数据采集,从中得出喀斯特石漠化区顶坛花椒根系的生长特征。表明顶坛花椒根系界于散生根型与水平根型之间,根系水平分布远大于垂直分布,反映了根系的发达性及浅根性的特点。根系主要分布在0~35 cm的土层中,吸收根一般分布0~30 cm范围内。土壤环境决定了根系的生长分布特征,土壤容重、土壤水分与根系分布显著相关(P<0.05);垂直方向上,所调查样株根系集中分布于有机质高的土壤上层;水平方向,各根系分布与土壤养分多寡没有明显关系,而更多受制于小地形条件。

Drought-resistance characters of karst plant of adaptability in Huajiang karst gorge Ⅰ:Root system of Zanthoxylum planispinum var. dintanensis and its soil environment

The distribution of Zanthoxylum planispinum var.dintanensis in different soil environment in Huajiang gorge area was studied.Factors influencing the root growth and distribution were analyzed by 15 plant samples.The distributed types of the root system were between heartroot and flatroot.The horizontal roots were much longer than the vertical ones reflecting the characters of shallow and developed roots.The root distribution depth was 0~35 cm,while the general distribution depth of fine-root was 0~30cm.The soil environment showed strong influence to the type of roots.The correlation analysis showed root system distribution was significant to the bulk density and soil water content(P<0.05). The sample root system in vertical direction concentrated on humus and upper mineral soil layers,but roots in horizontal direction did not have remarkable relation to rich or poor nutrient in the same soil layer.In horizon,root distribution was more influenced by the small topographty.