Abstract:

The population dynamic and quantitative characteristics of Haloxylon ammodendron in Gurbantunggut desert was analyzed based on a theory of population dynamics and spectral analysis. The results showed that the survival curve of H. ammodendron populations tended to be the type of Deevey-Ⅲ. The mortality rate of H. ammodendron was high at early stage and low at late stage. There existed 2-4 death peaks in the population life process. Spectral analysis showed the natural regeneration process of H . ammodendron population was expressed in fluctuation of the number distribution of trees in different age grades. The quantitative fluctuation of H . ammodendron population exhibited in large cycles within each which there were at least two small cycles. The influences of these cycles dropped with the diminishment of cycle length, and the effect of fundamental wave was more distinct. The fundamental wave was mainly affected by environmental factors, to a less degree by its biological characteristics. Upscaling process of spectrograph in different habitat showed that the small scale changed prominently, while the large scale was relative steady. Therefore, the sampling area of H. ammodendron population fluctuation in Gurbantunggut desert was 4 400－5 600 m² in relative environmental condition, and 4 400－9 200 m² in otherwise condition.

Key words: Haloxylon ammodendron, population dynamics, spectral analysis, scaling analysis