摘要
以生长于内蒙古浑善达克沙地上的特有种———褐沙蒿种群为对象,对处于植被演替不同阶段(流动沙地、半流动沙地、半固定沙地和固定沙地生境)的褐沙蒿种群生长状态和及其生境特征进行了观测。结果表明,随着沙地表层的逐步固定,土层0~5cm的土壤含水量在逐渐增加,雨后各样地内土壤含水量的最大值都出现在0~5cm表土层;土壤有机质、全氮含量在各样地间差异极为显著,并表现出随着沙地的固定逐渐增加的趋势。褐沙蒿基株数、构件的枝条数在各演替阶段间虽无显著的差异,但随土壤基质的改变,反映种群生态功能的特征,如冠幅、生物量、生殖配额等特征在各样地间却有显著差异,且表现出随着沙地的固定而下降的趋势。在此基础上尝试性地提出了褐沙蒿种群综合活力指数(CVI),试图以一个综合的指标来表示褐沙蒿种群在不同衰退阶段生长状态上的差异。分析表明,随着沙地的逐步固定,褐沙蒿种群综合活力指数在各演替阶段差异极为显著,其值从流动沙地的0.63显著下降到固定沙地的0.38,并与土壤有机质含量、全氮量之间表现出显著的负相关性。
Artemisia intramongolica is an important semi-shrub in the Hunshandake Sandy land and it has degraded significantly in the desert succession series from shifting to fixed sandy land.In order to find out the vital reasons of its degradation,the bioecological features and its habitat characteristics of A.intramongolica were studied in shifting,semi-shifting,semi-fixed and fixed sandy lands.The results showed that there was no significant difference in soil moisture among the different plots and the layers of soil before raining period.With the sandy land fixation,the soil moisture in 0~5 cm surface layer increased gradually.After raining period,though the soil moisture among plots had no significant difference,the maximum of soil moisture all occured in 0~5 cm surface layer.The contents of soil organic material and total nitrogen in plots were significantly different,which showed increase trend with the sandy land fixing.Though there was no significant difference among ramets and modules,the characteristics which reflected the ecological functions of population,such as canopy extension,biomass and reproductive allocation,were significantly different in plots and showed decline trend with the sandy land fixing.On this condition,the compositive vigour index (CVI) for A.intramongolica population was put forward to analyze the correlation between its characteristics and soil factors.It showed that with the sandy land fixing,there were significant difference between CVI of different succession stages.Its value decreased from 0.63 of shifting sandy land to 0.38 of the fixed,which negatively correlated with the contents of soil organic material and total nitrogen.
出处
《生态学杂志》
CAS
CSCD
北大核心
2005年第5期497-502,共6页
Chinese Journal of Ecology
基金
国家自然科学基金项目(30260022)
内蒙古自治区自然科学基金项目(20010905-12)
国家自然科学基金重点资助项目(30330120)。
关键词
褐沙蒿
种群
综合活力指数
Artemisia intramongolica,Population characteristics,compositive vigour index.