锰矿区重金属污染土壤对栾树和杜英光合作用的影响

Effect of heavy metal polluted soil of Manganese Mine on photosynthesis in Koelreuteria paniculata and Elaeocarpus decipens

采用湘潭锰矿区重金属污染土壤进行盆栽试验,设计了5个方案(对照CK:100%自然土;W1:25%矿区废弃地土壤+75%自然土;W2:50%矿区废弃地土壤+50%自然土;W3:75%矿区废弃地土壤+25%自然土;W4:100%矿区废弃地土壤),对比研究了锰矿区重金属污染土壤对栾树Koelreuteria paniculata、杜英Elaeocarpus decipens光合生理特性的影响。结果表明:(1)7月份杜英的净光合速率平均值高于栾树。(2)不同处理(W1、W2、W3、W4)下,栾树净光合速率日均值分别是对照区的66%、87%、106%、117%,杜英分别是对照区的73%、83%、72.7%、57%。(3)栾树的气孔导度日变化幅度的大小顺序为CK>W3>W4>W2>W1,杜英为CK>W3>W2>W4>W1,4种处理降低了其日变化幅度;栾树胞间CO2浓度日变化幅度大小顺序为W4>W1>CK>W3>W2,杜英为W1>W2>W4>CK>W3;4种处理减少了2树种蒸腾速率日变化幅度,且对应处理组的杜英最大值均高于栾树。

This paper focused on the impacts of photosynthetic physiological characteristics of Koelreuteria paniculata and Elaeocarpus decipens potted in heavy metal polluted soil from the slag wastelands of Xiangtan Manganese Mine by comparative study,five treatments were designed（CK：100% untreated soil;W1：75% untreated soil＋25%slag wasteland soil;W2：50% untreated soil＋ 50%slag wasteland soil;W3：25% untreated soil＋75% slag wasteland soil;W4：100% slag wasteland soil）.The results show that：（1） The average net photosynthetic rate（Pn） of Elaeocarpus decipens was higher than that of Koelreuteria paniculata in July;（2） For Koelreuteria paniculata,under four treatments,the average rates of（Pn）were 66%,87%,106%,117% compared to the contrast.While for Elaeocarpus decipens,the average rates of（Pn）were 73%,83%,72.7%,57% compared to the contrast.（3） the range of diurnal variations of（Gs）reduces,the order of the range of diurnal variation of Koelreuteria paniculata was CK〉 W3〉 W4 〉W2 〉W1,and Elaeocarpus decipens was CK〉 W3〉 W2〉 W4 〉W1.The order for the range of diurnal variation of intercellular CO2 concentration（Ci） of Koelreuteria paniculata from high to low was W4〉 W1〉 CK 〉W3〉 W2,while the order of Elaeocarpus decipens was W1〉W2〉W4〉CK〉W3.Four treatments reduced the range of diurnal variation of Tr,for each corresponding treatments,the maximum value of（Tr）of Elaeocarpus decipens was higher than that of Koelreuteria paniculata.