关键词: 丛枝菌根真菌, 重金属, 耐性, 功能差异

Abstract: The design and construction of sunlight greenhouse need to balance the stability and cost, which are mainly affected by the snow load (the maximum snow depth and snow pressure). In this paper, based on the observation data of snow depth collected from 179 weather stations from 1981 to 2010, the maximum snow depth and pressure for recurrence intervals of 5, 10, 20 and 30 years in Northeast China were calculated using the extreme value type I distribution function, and their distribution characteristics were analyzed. The maximum sustainable snow depth and snow pressure were determined based on the type of sunlight greenhouse structure and the characteristics of snowproof coverings. The critical indexes of snow pressure and snow depth for sunlight greenhouse collapsing were concluded. The results showed that the maximum snow depth and snow pressure increased from west to east in Northeast China. The maximum snow depth and snow pressure were higher in the eastern and northern Heilongjiang and eastern Jilin, being over 50 cm and 0.45 kN·m^-2, respectively. The maximum snow depth and snow pressure were low in the southwestern Heilongjiang, western Jilin, and western and southern Liaoning, with values of less than 30 cm and 0.25 kN·m^-2, respectively. Snowinduced disaster index for sunlight greenhouse varied depending on snow type and slope of greenhouse, and the snow depth that induced sunlight greenhouse collapsing was bigger for pure snow than for snowwater mixture. The snow depth of blizzard disaster increased with the slope angle of sunlight greenhouse increased from 30 to 40 degree. It could be concluded that south and west areas of Northeast China are more suitable for the development of sunlight greenhouse than north and east areas based on disaster index, snow depth and snow pressure, and light and heat conditions.

Key words: arbuscular mycorrhizal fungi, heavy metal, tolerance, functional difference.