Although the phenology of tropical plants has attracted much attention, its response to climate change is generally unclear because of the lack of long-term phenological records. With phonological data (1973-199) of tropical plants in Xishuangbanna Tropical Botanical Garden (XTBG, 21◦41’N, 101◦25’E), Prof. Zhang Yiping and his students conducted a study regarding the inter-annual phenological trends in tropical plants in Xishuangbanna.
In their study, the researchers analyzed the phenological data to test the hypothesis that the warming climate has led to consistent changes in the phenology of tropical plants as it has performed in temperate species. With the phenological records of more than 15 years, four phenological events (budburst, growing season, flowering and flowering duration) were studied of 21 deciduous tree species from five families (Bignoniaceae, Combretaceae, Dipterocarpaceae, Mimosaceae and Papilionaceae) were studied.
During the study period, 14 species (67%) showed consistent trends in phenology and the regional temperature increase appeared to be one of the major forces that caused those changes, which agreed with their hypothesis. Seven species (33%) presented delaying trends in budburst (average 1.4 d y−1) and such trend was more likely to be presented in those that started budburst earlier in the dry season. Four species (19%) showed trends of extension in growing season (average of 3.5 d y−1).Flowering duration of five species (24%) was shortened by average 2.1 d y−1 which was most likely to be the result of the decline in sunshine duration during the rainy season.
Although the study periods were slightly different among species, the results demonstrated the fact that the phenology of tropical plants has been affected by climate change significantly but the reaction has been somewhat different from temperate plants.
The study entitled “Phenological response of tropical plants to regional climate change in Xishuangbanna, south-western China” has been published in Journal of Tropical Ecology, 29 (2): 161-172, DOI: 10.1017/S0266467413000114
