Effects of SO2, NO2, and O3 on population development and morphological and physiological parameters of native herb layer species in a beech forest

Air Pollution tolerance indices (apti) of some plants around Otorogun Gas Plant in Delta State, Nigeria.

“…Air pollution can be defined as the human introduction into the atmosphere of chemicals, particulate matter or biological materials that cause harm or discomfort to humans, or other living organism or damage the environment (Anonymous 2008) Air pollution is a major problem arising mainly from industrialization (Odilora, et al 2006). Air pollutions can directly affect plants via leaves or indirectly via soil acidification (Steubing, et al 1989). It has also been reported that when exposed to air pollutants, most plant experience physiological changes before exhibiting visible damage to leaves (Dohmen, et al 1990).…”

Air pollution tolerance index of selected plants in industrial and urban areas of Vellore district

“…Chlorophyll pigments exist in highly organized state, and under stress, they may undergo several photochemical reactions, such as oxidation, reduction and reversible bleaching (Puckett et al,1973).The total chlorophyll contents of the selected plants at College farm recorded high values when compared to Arcot and Ranipet samples (Table 1,2 &3). The air pollution can directly affects the plants via leaves and the photosynthetic pigments are the most likely to be damaged (Steubing et al,1989;Singh et al,1990 andSandelius et al .,1995).The ascorbic acid, a stress reducing factor, associated with particular environmental conditions was also analyzed from the selected plants and the plants from College farm recorded low ascorbic acid content when compared to Arcot and Ranipet. The present investigation revealed a great deal of variation in the levels of Ascorbic acid content among the three different study areas.…”

Action of Pollutants Individually and in Combination

“…Although the authors provide stomatal density data only for A. ursinum, and there are no data for transpiration rates of H. helix, it seems reasonable to suggest that intrinsically low stomatal conductances of ivy may have conferred considerable resistance on this species by reducing the uptake of pollutants. As was stated by Steubing et al (1989), "population development integrates all biochemical and physiological effects of pollution (and is, in addition, affected by competition)." Continuing our theme of interrelationships between physiological responses, we conclude this section by considering the potential role of "chemical signalling" within plants .…”

“…Processes such as stomatal behavior, photosynthesis, biomass accumulation, and root:shoot partitioning should be quantified for each plant species over extended time periods to allow any changes in community structure to be related to interor intraspecific variations in critical physiological processes. An example of such an approach is the study by Steubing et al (1989) of the effects of S02' N0 2 , and 0 3 on herb layer species in a beech forest in Germany. They showed interspecific variations in responses to the pollution regimes, which translated into alterations in community structure.…”