黔中石漠化区衰老退化与正常生长顶坛花椒根区土壤质量特征

Aging and degradation of rocky desertification in Qianzhong area and soil quality features of root zone of normal Zanthoxylum planispimum var. dintanensis

关键词:  衰老退化, 顶坛花椒, 根区土壤质量, 主成分分析, 黔中石漠化区

Key words:  aging and degradation, Zanthoxylum planispimum var. dintanensis, quality of root-zone soil, principal component analysis(PCA), rocky desertification in Qianzhong area

摘要:

为了探讨顶坛花椒(Zanthoxylum planispimum var. dintanensis)衰老退化的原因,实现林分稳定与可持续性经营,该文以开黄花为典型标志的衰老退化植株和正常生长的植株为研究对象,采用土壤农业化学和环境矿物学的方法,分析不同植株根区土壤矿质元素含量,评价土壤综合质量。结果表明:(1)正常生长植株根区土壤的C、P、K、S、Se、Sr、Mo、氧化物等总体水平显著高于衰老退化植株,总氮、速效磷、速效氮、Cu、Pb、Zn、Cr 无显著差异,其他元素的变化规律不明显。元素的有效态含量亦对植株生长产生影响。从植物营养需求角度看,大量、中量、微量元素均对土壤质量产生支配效应。(2)根区土壤质量指数表现为正常生长植株3最高、衰老退化植株1最低,说明土壤质量对顶坛花椒衰老退化具有影响。(3)顶坛花椒林分经营时,应培育良好的土壤结构,注重土壤养分的全面性和均衡性,关注矿质元素过低引起的亏缺效应。

Abstract:

In order to discuss the reason for aging and degradation of Zanthoxylum planispimum var. dintanensis, and to realize the stabilization of forest stand and sustainable management, we took aging degraded plants with typical symbol of yellow blooms and normally grown plants as the research objects and adopted soil agrochemistry and environmental mineralogy methods to analyze mineral element content in root-zone soil of different plants, to evaluate integrated soil quality and to reveal the mineral element mechanism of aging and degradation of Zanthoxylum planispimum var. dintanensis. The results were as follows:(1)C, P, K, S, Se, Sr, Mo and oxide in root-zone soil of normally grown plants were generally higher than the content in aging degraded plants, while total nitrogen, rapidly available phosphorus, available nitrogen, Cu, Pb, Zn and Cr had no significant difference, and other elements had no obvious change rule. It indicates that mine-ral elements are one of the causes of the aging and degradation of Zanthoxylum planispimum var. dintanensis. Available contents of elements also had an impact on plant growth, which indicates that we should improve availability of nutrients when managing the Zanthoxylum planispimum var. dintanensis. From the perspective of plant nutrition demand, all major, medium and micro elements had a dominant effect on soil quality. In the management of soil fertility, we should not only focus on a large number of elements.(2)Root-zone soil quality indexes manifested that the highest plant was No. 3 normally grown plant and the lowest plant was No. 1 aging degraded plant, suggesting that soil quality influences the aging and degradation of Zanthoxylum planispimum var. dintanensis. But the soil quality is not the only cause of aging degradation of Zanthoxylum planispimum var. dintanensis, and more comparative studies of soil microbes and plant hormones should be conducted.(3)When managing the Zanthoxylum planispimum var. dintanensis in forest stand, we should cultivate good soil structure, make sure the comprehensiveness and proportionality of soil nutrient, and pay attention to deficit effect caused by low mineral elements, and it is necessary to make sure the appropriate nutrient concentration and ratio to increase the absorption capacity of the plant.