PARENT SESSION
Contributed Oral Session 59: Bacterial Communities and Diversity
Tuesday, August 9, 1:30 PM - 5:00 PM, Meeting Room 515 A, Level 5, Palais des congrès de Montréal
Meta-analysis of plant species richness in the vicinity of point polluters: Are pollution effects always detrimental?
Asikainen, Eija*,1, 1 Section of Ecology, Department of Biology, University of Turku, Turku, Finland
ABSTRACT- Although effects of air pollution on plants are widely studied, both at the level of community and individual species, the general pattern have not emerged yet, and sources of variation remain almost unexplored. We conducted a meta-analysis of published information on the impact of point polluters on plant species richness and diversity. We were interested in comparison of the effects on different plant groups in different regions, as well as in exploration of factors potentially explaining variation in responses. Primarily studies are highly biased: only one from nearly 100 studies was done in southern hemisphere; 66% of studies were conducted in boreal forests and 23% in temperate forests, while other biomes remain practically unexplored. Most of the studies were restricted to field layer, only 35% involved all vascular plants. Almost half of the studies were conducted in Russia and published in Russian, which naturally restricts their availability for the international scientific community. Although, as expected, diversity clearly decreased with increase of pollution, the pattern was not uniform among the plant groups; in some situations pollution effects were even beneficial. In general, we found no publication bias related to the results of primary studies since studies with small sample sizes included more variation than studies based on larger samples. However, we found bias related to publication policy, i.e., negative correlation between effect size and the year of publication. In other words, positive effects of air pollution to plant species richness have been started to publish only recently.
Key words: Air pollution, Meta-analysis, Plant species richness