Dynamic life table and survival analysis of Artemisia scoparia in the desert steppe of Yanchi County, Ningxia

Three soil types, including sandy soil, residual soil of weathered bedrock, and sierozem were used to equip a device to control rainfall and monitor the growth and survival of Artemisia scoparia for two consecutive years. The results showed that the survival curve of A. scoparia populations was similar to that of a Deevey type I curve, having a convex shape. From the interannual perspective, there was a significant difference in the number of A. scoparia between years. The number of A. scoparia in 2018 was higher than that in 2017. The number of populations reached the peak in July. According to soil type, the survival rate and cumulative survival rate of A. scoparia populations in the sierozem habitat were higher than those in the sandy soil and residual soil of weathered bedrock. Regarding the amount of rainfall, in sandy soil, the standardized survival of populations in increased rainfall treatment was higher than that in normal and decreased rainfall treatments in 2017, but the opposite was true in 2018. The standardized survival of populations in the increased rainfall treatments was lower in weathered bedrock and sierozem habitats. These results were mainly caused by precipitation and intraspecific competition. In conclusion, the survival number of A. scoparia populations was higher in the sierozem habitat. Furthermore, precipitation affected the survival of A. scoparia to a certain degree. In years with more rainfall, the intraspecific competition of the A. scoparia population increased, which reduced the population survival.