---

作 者 ：朴顺姬, 王振杰, 颜秀灵, 张斌才, 尹航

期 刊 ：植物生态学报 2006年 30卷 4期 页码：593-600

关键词：科尔沁沙地；差巴嘎蒿种群；生态位适宜度；

Keywords:Horqin sandy land, Artemisia halondendron population, Niche fitness,

摘 要 ：以生长在科尔沁沙地的差巴嘎蒿(Artemisia halodendron)为研究对象，对其在不同类型沙地上的综合活力指数和生态位适宜度进行计算，主要结论如下：1)在生长旺季，差巴嘎蒿种群综合活力指数随着沙地的固定显著下降。2)在同一生长季内，综合生态位适宜度表现为半固定沙地>固定沙地和流动沙地；水分生态位适宜度表现为流动沙地>半固定沙地>固定沙地。随着土壤含水量的变化，土壤水分的限制土层深度也有所不同：7月各类型沙地均为15～30 cm土层；8月随着雨水的下渗，限制土层也有所加深，为45～60 cm土层；9月除流动沙地为15～30 cm外，半固定沙地和固定沙地均为30～45 cm。3)在同一生长季内的不同生境上种群的限制因子(NFmin)不同：在流动沙地上为土壤有机质，而在半固定沙地和固定沙地上为土壤含水量，且土壤有机质和土壤水分的配置关系直接影响综合生态位适宜度值的高低。在一定范围
内，二者的比值可直接反映有机质对植物细根的有效性，同时种群通过调节细根生长状况来适应限制因子间的配置关系。

Abstract:Background and Aims Niche fitness of Artemisia halondendron population, that fixes shifting
and semi_fixed sandy soils in Horqin sandy land, rarely has been explored. This study
addresses 1) spatial and temporal differences in niche fitness and composite vigor and 2)
limiting factors of niche fitness in different habitats.
Methods Mathematical models were adapted to calculate composite vigor index (CVI) and niche
fitness values of a population of A. halondendron inhabiting shifting, semi_fixed, and
fixed sandy lands. Data on CVI and niche fitness were collected by measuring height, size
of canopy, branches, and biomass of individuals, as well as soil moisture content, nutrient
content, and bulk density.
Key Results CVI was remarkably low on fixed sandy land, indicating that the ecological
function of the population was weakened. Composite niche fitness values for different soils
during the growing season ranked: semi_fixed >fixed > shifting sandy land. Moisture fitness
values ranked: shifting > semi_fixed >fixed sandy land. As the soil moisture content
changed, the limiting layer also changed. It was 15-30 cm in the different sandy lands in
July, but with the infiltration of rain water, the layer deepened to 45-60 cm in August. In
September, it was 30-45 cm in semi_fixed and fixed sandy lands, but remained 15-30 cm in
shifting sandy land. The limiting factors in different habitats were different: soil
organic matter content was limiting on shifting sandy land and soil moisture content was
limiting on semi_fixed and fixed sandy l ands.
Conclusions This study indicated that soil moisture content and nutrient content affected
composite niche fitness. The relationship of soil moisture content and nutrient content
directly influences composite niche fitness. Their ratio could reflect the importance of
organic matter to fine roots, and the population could adapt to the ratio by adjusting the
growth of fine roots.

---