温度变化对天山云杉凋落物3,4-二羟基苯乙酮自毒作用的影响

目的]在全球气候变暖背景下,检验“自毒作用对天山云杉天然更新障碍温度效应假设”,为应对气候变化的天山云杉林保育与可持续经营提供科学依据.方法]以天山云杉生长季(5～8月)天然林地表层(1 ～5 cm)土壤昼(光同期)夜(暗同期)平均温度(12℃,4℃)为基准,采用智能环境模拟温度变化对天山云杉凋落物3,4-二羟基苯乙酮(DHAP)自毒作用的影响.结果]温度≥(14℃,6℃),DHAP处理液浓度≥7.5mM时,显著或极显著抑制天山云杉种子萌发,并对幼苗生长表现出显著的抑制作用.结论]温度升高会增强DHAP的活性,降低其产生自毒效应的临界浓度,使天山云杉天然更新更易受到自毒作用的影响.

Effects of Temperature Change on 3,4 - Dihydroxyacetophenone Autotoxicity of Picea Schrenkiana Needle Litters

Objective]The purpose of this research was to provide scientific basis for Picea schrenkiana Fisch.et Mey.forest conservation and sustainable management to combat climate change under the background of global warming,which might be important to test the assumption that autotoxicity has temperature effects on natural regeneration barriers of P.schrenkiana.Method]The average temperatures of day(photoperiod) of the surface soil(1 - 5 cm) and night(dark period) of P.schrenkiana natural woodland in growing season (May to Aug.) was set as benchmark,and the method of intelligent environment was used to simulates the effects of temperature change on 3,4 - dihydroxyacetophenone(DHAP) autotoxicity of needle litters from P. schrenkiana.Result]While the temperature was≥(12℃,4℃),and the concentration of DHAP was≥7.5 mM,significant or remarkably significant inhibition on P.schrenkiana seed germination was displayed,which presents significant inhibition on seedling growth.Conclusion]Temperature increasing will enhance the activity of DHAP,reduce the critical concentration and inhibit producing autotoxicity by itself,which has deep influence on natural regeneration of P.schrenkianay.