Phenological basis of determining tourism seasons for ornamental plants in central and eastern China

Many plants have high ornamental value during specific phenophases, and plant phenology correlates highly with seasonal vegetation landscape. Determination of the span and spatiotemporal patterns of the tourism season for ornamental plants could provide tourism administrators and the tourists themselves with a theoretical basis for making travel arrangements. Based on data derived from on-the-ground observations of three phenophases, specifically first leafing date, full flowering date, and end of leaf coloring date, and corresponding meteorological data at 12 sites in China, we divided the tourism season into its starting date, peak (best date) and end date for ornamental plants by computing frequency distributions of these phenophases. We also determined how the peak of this tourism season changed during the course of the past 50 years. We found that: (1) The peak of the tourism season ranged from March 16 (in Guilin) to May 5 (in Harbin) for first leafing, from April 3 (in Kunming) to May 24 (in Mudanjiang) for full flowering, and from October 1 (in Mudanjiang) to November 30 (in Shanghai) for leaf coloring. As might be expected, the peaks of both the first leafing and full flowering tourism seasons were positively associated with latitude, while for leaf coloring it was negatively correlated with latitude. (2) The ideal tourism season for first leafing and full flowering advanced by more than 0.16 days/year over the past 50 years in Beijing and Xi'an, while the peak of the tourism season for leaf coloring became significantly delayed (by 0.16 days/year in Beijing and 0.21 days/year in Xi'an). (3) The tourism season was significantly associated with temperature across related phenological observation sites. The ideal time for first leafing and full flowering was determined to have advanced, respectively, by 4.02 days and 4.04 days per 1 degrees C increase in the spring (March-May) temperature. From September to November, the best time for leaf coloring correlated significantly and positively with average temperature, and the spatial sensitivity was 2.98 days/degrees C.