1) How do pollutants stress plants? Analyses of plant performance on pollution gradients in Harjavalta (SW Finland) and Kola (NW Russia) offer data from large-scale, unintentional experiments. We have especially tried to find general measures to quantify plant stress, e.g.by chemical analyses and by monitoring fluctuating asymmetry of leaves.
Relevant literature:
Kozlov, M. V., Haukioja, E., Bakhtiarov, A. V. and Stroganov, D. V. 1995. Heavy metals in birch leaves around a nickel-copper smelter at Monchegorsk, Northwestern Russia. - Environ. Pollut. 90: 291-299
Kozlov, M. V., Wilsey, B. J., Koricheva, J. and Haukioja, E. 1996. Fluctuating asymmetry of birch leaves increases under pollution impact. J. Appl. Ecol. 33: 1489 1495.
Koricheva, J., Roy, S., Vranjic, J. A., Haukioja, E., Hughes, P. R. and Hänninen, O. 1997. Antioxidant responses to simulated acid rain and heavy metal deposition in birch seedlings. Environ. Pollut. 95: 249 258.
Zvereva, E. L., Kozlov, M. V. and Haukioja, E. 1997. Stress responses of Salix borealis to pollution and defoliation. J. Appl. Ecol. 34: 1387-1396.
Loponen, J., Ossipov, V., Koricheva, J., Haukioja, E. and Pihlaja, K. 1997. Low molecular mass phenolics in foliage of Betula pubescens Ehr. in relation to aerial pollution. - Chemosphere 34: 687 697.
Loponen, J., Ossipov, V., Lempa, K., Haukioja, E. and Pihlaja, K. 1998. Concentrations and among-compound correlations of individual phenolics in white birch leaves under air pollution stress. - Chemosphere 37: 1445-1456.
Saikkonen, K., Koivunen, S., Vuorisalo, T. and Mutikainen, P. 1998. Interactive effects of reproductive manipulation and growth limiting heavy metal pollution on resource allocation in Potentilla anserina L. Ecology 79: 1620-1629.
Kozlov MV, Haukioja E, Bakhtiarov AV, Stroganov DV, Ziminac SN
(2000) Root versus canopy uptake of heavy metals by birch in an industrially
polluted area: contrasting behaviour of nickel and copper. Environ.Pollut. 107:
413-420.
2) Recovery potential. A large projects to study possibilities of plants to recover after decrease in pollution levels is under way with plant physiologists (factors relating to photosynthesis) and organic chemists (factors relating to mec hanisms of DNA damage and repair) from Harjavalta and from Kola peninsula. The project includes field studies at both the areas, as well as laboratory work based on cloned birch materials from the sites. Reduction of emissions in Harjavalta gives possibil its to utilize field data, too.
Kozlov MV, Haukioja E (1999) Performance of birch seedlings replanted in heavily polluted industrial barrens of the Kola peninsula, NW Russia.
Restor.Ecol. 7:145-154
2) General aspects of plant stress on invertebrate herbivores Plant stress is assumed to change plants more palatable for herbivores. However, literature analyses about effects of abiotic stresses on woody plants revealed no general stress effects, except that sucking insects perform better on stressed plants. Our gradient analyses have indicated that increased fluctuating asymmetry of leaves was a consequence, but not the cause, of insect defoliations.
Relevant literature:
Koricheva, J. and Haukioja, E. 1994. The relationship between abundance and performance of Eriocrania miners in the field: effects of the scale and larval traits studied. - J. Anim. Ecol. 63: 714-726.
Zvereva, E. L., Kozlov, M. and Neuvonen, S. 1995. Decrease in feeding niche breadth of Melasoma lapponica (Coleoptera: Chrysomelidae) with increase in pollution. - Oecologia 104: 323-329;
Zvereva, E. L. and Kozlov, M. V. 1996. Avoidance of willows from moderately polluted area by leaf beetle, Melasoma lapponica: effects of emission or induced resistance? - Entomol. exp. appl. 79: 355-362.
Zvereva, E. L., Kozlov, M. V., Niemelä, P. and Haukioja, E. 1997. Delayed induced resistance and increase in leaf fluctuating asymmetry as responses of Salix borealis to insect herbivory. -Oecologia 109: 368-373
Koricheva, J., Larsson, S. and Haukioja, E. 1998. Insect performance on experimentally stressed woody plants: a meta analysis. -Annu. Rev. Ent. 43: 195-216.
Kozlov MV, Haukioja E, Kovnatsky EF 1999 Uptake and excretion of nickel and copper by leaf mining larvae of Eriocrania semipurpurella (Lepidoptera: Eriocraniidae) feeding on contaminated birch foliage. Environ.Pollut. 108: 303-310.