Correlation between environmental conditions and Foliar chemical parameters in Ligustrum lucidum Ait. exposed to urban air pollutants

A diagnostic study was made ofLigustrum lucidumAit. in relation to atmospheric pollutants in Córdoba city, Argentina. The study area receives regional pollutants, and it was categorized by taking into account traffic level, industrial density, type of industry, position of the sample point in relation to the corner, treeless condition and topographic level. Dried weight/fresh weight ratio (DW/FW) and Specific Leaf Area (SLA) were calculated; and concentration of chlorophylls, carotenoids, total sulphur, soluble proteins, malondialdehyde and hydroperoxy conjugated dienes were determined for leaf samples. Malondialdehyde correlates positively with traffic density; foliar sulphur correlates negatively with type of industry; and, finally, DW/FW ratio and SLA correlates negatively with treeless conditions. On the other hand, the concentration of photosynthetic pigments correlates negatively with sulphur, hydroperoxy conjugated dienes, proteins, DW/FW ratio and SLA. Pollution-induced changes in one parameter alone may not be sufficient to draw a clear picture of the situation. An approximation to predict tree injury may be obtained by measuring sulphur content, SLA, hydroperoxy conjugated dienes, proteins, chlorophyll a and chlorophyll b. These parameters could be combined to obtain a general index of air pollution, as they are responsible for the major variability of the data.