Flower production
In the permanent plots, flowering of 81 species (62% of all species) was recorded throughout the survey periods in which 21 species were categorized as bee-visited type, 53 species were fly-visited type, and 7 species were other type. Both the number of flowering species and diversity index (H’ ) were small in the early season and large in the middle season (Table 1). This trend was more apparent in bee-visited species in which H’ values ranged from 0.3–3.3, while seasonal changes in fly-visited species were moderate in which H’ values ranged from 2.3–3.4. The NMDS result conducted for all species showed that variation in floral compositions across the survey periods was largely explained by seasonal difference (effect size,R 2 = 0.75), while yearly variation was negligibly small (Fig. S2). Similar trends were detected when NMDS was performed for bee-visited species and fly-visited species separately, although the effect size of bee-visited species (R 2 = 0.86) was larger than that of fly-visited species (R 2 = 0.68). These results indicate that seasonal progress and species transition of flowering plants are more apparent in bee-visited plants than in fly-visited plants.
The number of flowers per plot highly varied among plots across seasons in both bee-visited and fly-visited species (Fig. 3). The GLMM result showed that flower production in the early season was significantly smaller than that of the middle and late seasons (Table 2). Significant negative interactions were detected between fly-visited species and season, suggesting that the seasonal changes in flower production were moderate in fly-visited species compared to bee-visited species (Fig. 3).