喀斯特小流域植被-土壤系统钙的协变关系研究

分析和探讨了贵州花江峡谷查尔岩小流域不同生态系统中土壤和植物中总钙与不同存在形态钙的含量及其相互之间的关系。研究区土壤中,不仅总钙含量(平均1.8%)高,而且交换态钙含量(平均占总钙含量的50.9%)也很高,与土壤总钙含量显著正相关。植物总钙含量(平均在1.2%-3.2%之间)高,且在不同层次间有较大的差别,灌木层钙含量(平均2.3%)大于草本层(平均1.2%)。不同物种间钙含量变化也较大,在研究区所有物种中构树钙含量最高(平均3.2%)。植物中三种形态钙(水溶性钙、乙酸溶性钙、盐酸溶性钙)含量以水溶性钙含量最高,但并不随植物总钙含量的增加而增加,且在不同植被中含量相差较大。植物、土壤总钙及土壤交换态钙含量,都随着次生林、草灌、灌草、稀疏灌草的演替有增加的趋势。土壤-植被间钙含量的相关性分析表明,高钙的土壤环境是导致植物钙生物吸收系数高的主要原因。

Ca COVARIANT RELATION IN PLANT-SOIL SYSTEM IN A SMALL KARST CATCHMENT

Total and different forms of Ca contents and their relationships with soil and plant in different ecosystem of Chaeryan catchment was studied in Guizhou Huajiang gorge area.The results elucidated that both total Ca content(average 1.8%) was high and the exchangeable Ca content(average 50.9% of total Ca content) were high with significant positive correlation.The total Ca content(average 1.2% to 3.2%) in plant was high but existed relatively distinction among different layers.The total Ca content(average 2.3%) in shrub was higher than that in herbage(average 1.2%).The variation of total Ca content was evidently different among plant species,and the total Ca content in common papermulberry was the highest.The water soluble Ca content was higher than those in acetic acid and hydrochloric acid soluble Ca in plant.The water soluble content of Ca had no correlation with total Ca in plant.The total and exchangeable Ca in soil and the total Ca in plant increased with the plant succession from arbor trees,herbage-shrubs,shrubs-herbage to sparse shrub-herbage.The correlation analysis of total Ca content in soil and plant elucidated that high Ca bio-absorption coefficient in plant resulted from high Ca content in soil.