Pollen of giant ragweed (GR), an annual non-native invasive weed, causes serious respiratory allergies in some humans and animals. Chemical control of GR in grassland can produce toxic side effects in herbs and livestock. This paper discusses methods used to prevent infestation and to control this species by analyzing the soil seed bank (SSB) and limiting the invasiveness of GR.

By studying GR distributed in grassland of the Yili Valley, Xinjiang, China, this paper compares the spatial and temporal changes of seed density along with seed germination, dormancy, and death at different times after invasion and in different soil layers. The study analyzed population characteristics over time, seed fate, and control methods for this species with the goal of reducing the of SSB density of GR.

The SSB of GR in grassland occurs mainly in the 0–5 cm soil layer but also to depths of 15 cm. Seed density in the SSB decreased by 68.1% to 82.01% from the seed maturity period to the early non-fertile period. >98.7% of the seeds rotten, eaten, germinated, dispersed or died within one year after being produced. The seed germination rate of the SBB decreased with an increasing number of years after invasion. When stored for 1 or 4 years, seed germination rates fell by 40%, during which time seed mortality increased by almost 40%. When GR was completely eradicated for 2 consecutive years, the SSB and population densities decreased by >99%.

The vast majority of GR seeds germinated or died within one year; long term dry storage also significantly decreased the germination rate. Newly produced seeds are the main source of seeds in the SSB; seeds have a strong ability to germinate. Therefore, thoroughly eradicating GR plants for several years before the seeds can mature provides an effective control method in grasslands.