辽西北部主要绿化树种对粉尘污染的生理响应研究

为探究乡土和外来树种对城市不同污染环境的适应性，选取阜新市工业区、道路、矿区和公园绿地共有的10种树种作为研究对象，采用洗脱法测定了各树种单位叶面积滞尘量，并测定了叶片滞尘前后生理指标的变化，探讨不同种树叶片滞尘效应，以及叶片滞尘后对植物生理活动的影响。结果表明：(1)在4个功能区的不同树种单位叶面积滞尘量均不同，其中新疆杨单位叶面积滞尘量都较高、均值为1.45 g/m²，银杏单位叶面积滞尘量都较低、均值仅有0.92 g/m²。(2)叶片滞尘之后生理指标分析显示，叶片SPAD值呈显著下降趋势，渗透调节物质(脯氨酸、可溶性蛋白、可溶性糖)含量和细胞膜透性(MDA、Rec)均呈上升趋势，而抗氧化酶活性(SOD和POD)呈下降趋势但下降率不明显。(3)银杏和五角枫滞尘量与各生理指标之间有显著相关关系，更适合从生理方面检测城市粉尘污染环境指示物。(4)4个功能区不同树种滞尘能力与抗尘能力聚类分析显示，新疆杨、紫丁香、山皂荚和臭椿的滞尘能力和抗尘能力均较强；阜新市外来树种新疆杨、紫叶李、臭椿等的滞尘和抗尘能力均与乡土树种相当。研究认为，在长期粉尘污染胁迫下，各绿化树种可能通过提高渗透调节物质含量和抗氧化酶的活性等来缓解粉尘污染的伤害，外来树种与乡土树种同样在各污染环境中表现出较强的适应能力；在不造成生物入侵危害的前提下应该积极引进能够有效滞尘和治沙防风的外来树种。

Physiological Response of Main Greening Tree Species to Dust Pollution in Northwest of Liaoning Province

To explore the native and exotic species of adaptability to different environmental pollution in the city, in this study, we selected 10 tree species in the industrial area, road, mining area and park green space of Fuxin City as the research objects. We measured the dust retention per leaf area of tree species and the changes of physiological indexes of leaves before and after dust retention by the elution method, and discussed the dust detention effect of leaves in different trees and the influence of leaves on physiological activities of plants after the dust detention effect. The results indicate that: (1) different tree species have different dust retention per unit area. The dust retention of Populus bolleana was 1.45 g/m² which is higher than that of others and Ginkgo biloba was only 0.92 g/m2 which is lower than that of others in all 10 tree species. (2) SPAD value of leaves showed a significant downward trend, contents of osmotic regulatory substances (proline, soluble protein, soluble sugar) and membrane permeability (MDA, Rec) showed an upward trend, while activities of antioxidant enzymes (SOD and POD) showed a downward trend, but the rate of decline was not obvious. (3) There was a significant correlation between the amount of dust held by G. biloba and Acer mono. It was more suitable to detect the indicators of urban dust pollution from the physiological aspect. (4) According to the clustering analysis of dust retention and dust resistance of different tree species in four functional areas, the dust retention and dust resistance of P. bolleana, Syringa oblata, Gleditsia japonica and Ailanthus altissima were both strong.The dust retention and dust resistance of foreign tree species in Fuxin City were similar to that of native tree species. Therefore, under the long term dust pollution stress, each tree species may alleviate the damage of dust pollution by increasing the contents of osmotic regulation substances and the activities of antioxidant enzymes. The foreign tree species and native tree species both show strong adaptability and are not sensitive to environmental pollution. Therefore, it is a strong guarantee for the safe and healthy development of urban landscape in arid areas to introduce foreign tree species which can effectively hold dust and control sand and prevent wind without causing biological invasion.