Abstract:
Based on the analysis of the variations in air temperature, precipitation, and sunshine hour in last 40 years in Taihu Lake region, a statistical analysis was made on the relationships between the climatic change and the occurrence time, frequency, and grade of cyanobacterial bloom in Taihu Lake. In the study region, the overall climate change trend from 1961 to 2007 was that the mean annual air temperature increased by 0.35 ℃·10a^-1, annual total precipitation increased by 31.33 mm·10 a^-1, and annual total sunshine duration decreased by 69.00 h·10 a^-1. The turning points of the variations in air temperature, precipitation, and sunshine hour were in 1989, 1979, and 1999, respectively. In 2000-2007, the climate changed exceptionally, which was mainly manifested in the rapid increase of air temperature (about 3.7 times of that in 1961-2007 and more obviously in May and October), the decrease of precipitation (about 178.10 mm·10 a^-1 less than that in 1961-2007), and the increase of sunshine hour (244.23 h·10 a^-1 more than that in 1961-2007). The increasing speed of climate warming provided thermal advantages for cyanobacteria growth, and the decreasing precipitation worsened the water quality and made the cyanobacterial bloom occurred more quickly. The increasing sunshine provided ample illumination to cyanobacteria growth. The climate trend of elevated air temperature, decreasing precipitation, and increasing sunshine hour was corresponded to the more frequencies of cyanobacterial bloom occurrence in Taihu Lake, leading to the appearance of cyanobacterial bloom in the Lake more and more seriously.

Key words: Succession, Tropical secondary forest, Soil arthropod communities, Structure and diversity