Adaptability of landscape tree species response to climate change in Shanghai within the past 55 years

ObjectiveIn recent years, research on tree's adapting to climate change has become a hot topic in the world. So far there are few researches on adaptability of landscape tree species response to climate change in China. Based on temperature and precipitation data from 1961 to 2015 in Shanghai, climate adaptation of 40 landscape tree species was assessed quantitatively, and the potential impacts of climate change on their growth were analyzed in the future scenarios.

MethodThe SDM (Species distribution model) was used to collect the comprehensive geographical information of the target species worldwide, then the climatic data of all occurrences were extracted to identify their climate characters. The most suitable climatic characters were finally determined by the Euclidean Distance Method to calculate the differences between the optimal factors and state of Shanghai climate in different periods.

ResultIn the past 55 years, annual mean temperature (AMT) of Shanghai rose from 15.5 to 16.6℃. The increasing trend of temperature difference in the downtown was most prominent, but it did not reach a significant level. Annual mean precipitation (AMP) also went up from 1086.0 to 1198.9mm, and in humidity season, changes of average precipitation in overall city, among suburban areas, between urban and suburban areas all reached significant levels. According to annual mean biological temperature (ABT) and dry-wet index (HI), 40 target tree species can be categorized into 4 types: hot-dry climate type, warm-humid climate type, cool-dry climate type and cool-humid climate type. In the first 30 years, the climate conditions in suburbs are suitable for the growth of deciduous trees preferring cool-dry climate, followed by cool-humid tree species, and warm-humid tree species, then hot-dry climate type tree species. However, in the recent 30 years, the climate in the downtown has changed dramatically. The adaptability of the warm-humid tree species has taken the advantage, and the cool-humid tree species and the cool-dry tree species have declined in turn.

ConclusionIn the past 55 years, the characteristics of climate change in Shanghai can be summarized as temperature warming and precipitation increasing in the rainy season. Climate change has potential impacts on the adaptability of landscape tree species, and has changed the priority sequence for tree species selection.