Abstract:

Based on the phenological and meteorological observation data of lilac from 10 stations of Heilongjiang meteorological observation network and the average distribution of phenological period, the variation trend of each phenological period and the influence of meteorological factors on phenological period in the past 30 years were analyzed to provide theoretical basis for scientific assessment of the impact of climate change on ecosystem and eco-tourism planning. The results showed that there were significant interannual changes in the phenological stage of lilacs in spring, the earliest and the latest dates of inflorescence in bud expanding stage, bud opening stage and leaf spreading stage differed by 18-25 days, and the trend of year after 2010 was advanced year by year. The duration of flowering was 14 days on average, the shortest was 9 days, and the longest was 18 days. In the phenological period of autumn, the difference between the beginning and the end of deciduous leaves was 15 and 12 days, and some years fluctuated greatly. The length of deciduous period averaged 16 days. The phenological period of spring was mainly related to the climatic factors in October and December of the previous year and the February-April of the current year, and the temperature in March and April was significantly negatively related. The temperature changes in this period determined the advance or delay of the phenological period, while the influence of precipitation and sunshine was relatively small in each period. The defoliation period was positively correlated with temperature and precipitation, but negatively correlated with sunshine. The results provide a basis for studying the ecological impact of regional climate change.

Key words: Lilac, phenology, climate change, Heilongjiang