Abstract:

The appropriate utilization of enclosure is a crucial strategy for ecological management and population recovery in desert steppe ecosystems. Limited research has been conducted on the impact of enclosure on the pollination efficiency of Ammopiptanthus mongolicus. Floral traits and insect pollination play important roles in the sexual reproduction of terrestrial plant communities， exerting significant influence on pollination success. To elucidate the mechanism underlying floral traits' impact on pollination efficiency， we conducted observations on floral traits， pollinator visitation frequency and behavior， as well as female fitness of A. mongolicus in both enclosed and natural habitats. Our results revealed that the number of open flowers in the enclosed habitat was significantly higher than that in the natural habitat， with Apis mellifera being the predominant visitor. The pollen limitation index was higher in the natural habitat， indicating a more severe pollen limitation within this population. Additionally， a notable positive correlation was observed between the number of open flowers and pollinator visitation frequency， and increased pollinator visitation frequency significantly enhanced female fitness. Our founding suggested that plant populations within enclosed habitats exhibit floral traits adapted to insect pollination， leading to a higher number of open flowers which can elevate pollinator visitation frequency and subsequently enhance the pollination efficiency of A. mongolicus. Enclosure treatment proves beneficial for enhancing sexual reproduction efficiency of A. mongolicus in desert steppe.

Key words: enclosure, floral straits, pollen limitation, pollinator visitation frequency, female fitness