2024年2月28日 星期三
重庆市阔柄杜鹃种群特征及其与环境因子的关系
Population characteristics of Rhododendron platypodum and its relationship with environmental factors in Chongqing City
2022年 第31卷 第1期 页码[61-68]    下载全文[1.1MB]  
摘要

采用典型样方调查法,调查重庆东南部金佛山、赵云山和白马山中阔柄杜鹃(Rhododendron platypodum Diels)的种群特征及其环境因子,并对二者的关系进行分析。结果表明:阔柄杜鹃种群分布于海拔1 709~2 152 m,样方间生境差异较大,在坡度陡峭、阳坡、树冠和地表透光率高、土层厚且有枯枝落叶层覆盖的生境有较多分布;阔柄杜鹃种群成年植株和幼苗密度较低,平均值分别为1 373.7和252.6 hm-2,基径和成年植株株高较小,平均值分别为12.0 cm和2.2 m,开花株比率较高,平均值为75.8%,但枝条开花率较低,平均值为22.1%。阔柄杜鹃种群个体数随径级增加总体呈先增加后减少的变化趋势,径级结构完整。阔柄杜鹃的种群存活曲线符合Deevey-Ⅰ型曲线,种群早期的个体死亡率较低,绝大多数个体能活到其生理寿命。阔柄杜鹃种群特征与环境因子关系复杂,可用直线、二次三项式和三次四项式描述,较高的树冠和地表透光率以及土层厚且有苔藓覆盖土壤能够显著促进阔柄杜鹃幼苗更新及开花。阔柄杜鹃种群分布的生境特殊,成年植株及幼苗密度较低,易于濒危,在管理中应加强生境保护及合理促进幼苗更新。

Abstract

The population characteristics and environmental factors of Rhododendron platypodum Diels in Jinfo Mountain, Zhaoyun Mountain, and Baima Mountain of Southeast Chongqing were investigated by using typical plot survey method, and the relationships between them were analyzed. The results show that R. platypodum populations distribute at the elevation of 1 709-2 152 m, and the habitats among quadrats are quite different and more populations are distributed in the habitats with steep slope, sunny aspect, high canopy and surface transmittance, and thick soil covered with litter. The densities of adult plants and seedlings of R. platypodum populations are low, with the means of 1 373.7 and 252.6 hm-2 respectively; the basal diameter and adult plant height are small, with the means of 12.0 cm and 2.2 m respectively; the percentage of flowering plants is high, with the mean of 75.8%, but the percentage of flowering branches is low, with the mean of 22.1%. With the increase of diameter class, the individual numbers of R. platypodum populations show a tendency to first increase and then decrease in general, and the structure of diameter class is complete. The survival curve of R. platypodum populations is in accordance with the Deevey-Ⅰ type curve, the early mortality rates of the individuals in the populations are low, and most of them can live to the physiological life span of the species. The relationships between population characteristics and environmental factors are complicate, which can be described by linear, quadratic trinomial, and cubic tetranomial, higher canopy and surface transmittance and thick soil covered with moss can significantly promote seedling regeneration and flowering of R. platypodum. The habitats in which R. platypodum populations are distributed are special, and the densities of adult plants and seedlings are low, making it is easy to be endangered. Therefore, habitat protection should be strengthened and seedling regeneration should be promoted reasonably in the management of R. platypodum populations.

关键词阔柄杜鹃; 种群静态生命表; 存活曲线; 种群结构; 环境因子
Key wordsRhododendron platypodum Diels; population static life table; survival curve; population structure; environmental factor
作者王梓卓1, 马立辉1,2, 王海洋1
所在单位1. 西南大学园艺园林学院, 重庆 400716; 2. 重庆市林业科学研究院, 重庆 400036
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基金项目重庆市科技兴林攻关类项目(2018-14)