This dataset contains data from a field experiments described in the paper: “Hou, Q., Zhao, X., Pang, X., Duan, M., Ehmet, N., Shao, W., & Sun, K. (2022). Why flowers close at noon? A case study of an alpine species Gentianopsis paludosa (Gentianaceae). Ecology and Evolution, 12, e8490. https://doi.org/10.1002/ece3.8490”.

The experiment investigates the effects of temperature (T), relative humidity (RH), and illumination intensity (II) on G. paludosa's flower closure, and monitored the environmental changes inside and outside of the flowers, aiming to test the effect of floral closure on the stability of microenvironment inside the flower. Finally, the temporal petal closure is artificially interrupted and investigated its effects on reproductive fitness.

In the first experiment, the floral movements of G. paludosa and microenvironmental climate conditions were monitored in the full bloom stage in the field.

In the second experiment, to tested whether changed environmental conditions could influence floral movement, and, which environmental factors could influence floral movement, the following experiments were carried out. Firstly, to test whether changed ambient conditions would stimulate closing or re-opening respectively, conducted the following 9 treatments from then on, and recorded the corolla width per half-hour: (1) closing T; (2) opening T; (3) blooming T; (4) closing II; (5) opening II; (6) blooming II; (7) closing RH; (8) opening RH; (9) blooming RH. Secondly, the following treatments were conducted to explore whether changed environmental conditions would delay the floral closure: (1) blooming T; (2) blooming II; (3) blooming RH. Thirdly, the 2-factor-combined treatments on full-blooming period and closed period flowers were conducted to test the effect of 2-factor-combined on flower closure.

In the third experiment, the temperature and relative humidity inside and outside the flower were tested to explore whether floral closure provide a stable microenvironment condition inside the flower.

In the fourth experiment, the effect of floral closure on seed production was tested in the field. 4 treatments were conducted when flowers opened: (1) compulsive openness; (2) forced closure; (3) delayed closure; (4) control group.

Main results of the experiments are that (1) high/low temperature contributed more to the flower closure than low RH, while illumination intensity had no significant effect on it; (2) the medium temperature, relative humidity and illumination intensity (environmental conditions at 10:00) did not delay flower closure when flowers at pre-closing period or stimulate reopen when flowers full closed; (3) floral closure provided a stable temperature condition and a higher RH condition inside the flower.; (4) compulsive opening and delayed closure of flowers decreased the seed-set ratio while no effect was found when flowers were forced to close..

The dataset was collected during a field study at the Alpine Meadow Ecosystem Scientific Research Station of Lanzhou University at Gannan and has been processed by paired-samples t test and ANOVA (SPSS 13.0) to produce a MS accepted for publication in Ecology and Evolution.