关键词: 苹果连作障碍, 土壤微生物, 残次苹果发酵产物, 土壤养分

Abstract: The microclimate regulation ability of plants is of great significance for improving the comfort of living environment in urban public spaces. Taking the parks and plazas in Nanjing City as the research objects, we analyzed the differences of temperature, humidity and thermal comfort (measured by temperature-humidity index) regulating ability of five structural types of communities (including single-layer grassland, evergreen single-layer woodland, evergreen tree-grass composite woodland, deciduous singlelayer woodland, and deciduous tree-grass composite woodland) in winter and summer by field measurement. The results showed that in summer, all communities had significant or extremely significant cooling and humidification effects (P<0.05 orP<0.01), but there was no significant difference among the four woodland types in their cooling and thermal comfort regulating ability. The effects of regulating temperature, humidity and thermal comfort of four woodland types were significantly or extremely significantly higher than those of the grassland (P<0.05 or P<0.01). In winter, the evergreen single-layer tree woodland or evergreen tree-grass composite woodland worsened the thermal comfort with significant cooling effect (P<0.05 or P<0.01), while the grassland and deciduous woodlands had no significant effect on microclimate. Except for the significant interaction between the deciduous tree and the understory in cooling effect in summer (P<0.05), the understory and the tree layer had no significant interaction in terms of other microclimate regulation effects. Our results suggested that the proportion of deciduous woodland could be increased to improve thermal comfort in cold winter and hot summer regions.

Key words: residual apple fermentation product, soil microorganism, apple replant disease, soil nutrient