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The Effects of Atmospheric CO2 Enrichment on Seed Germination
Marty, C. and BassiriRad, H. 2014. Seed germination and rising atmospheric CO2 concentration: a meta-analysis of parental and direct effects. New Phytologist 202: 401-414.

The authors write that "early life-history traits such as germination success and speed of germination have a marked influence on population and community dynamics," citing the work of Harper (1977), Grime et al. (1981), Garwood (1983), Fenner (1985), Menges (1991), Baskin and Baskin (1998), Leishman et al. (1999), Clauss and Venable (2000), Radford and Cousens (2000) and Edwards et al. (2001). However, they indicate that "despite this central role of intergenerational dynamics, we know very little about responses of reproductive success and seed germination to parental CO2 enrichment (Steinger et al., 2000)."

What was done
Hoping to shed more light on the subject, Marty and BassiriRad employed "a meta-analytic approach to summarize literature results of seed germination characteristics in response to parental CO2 enrichment (eCO2)," while also analyzing "the direct effects of eCO2 on germination components," based on data that "came from 29 original research papers encompassing 64 species and 116 observations."

What was learned
The two researchers report that "across all studies, parental eCO2 increased subsequent germination by 9%," and that "despite a considerable interspecific variability," they found "a positive correlation between germination success and seed mass responses to parental eCO2," with the response being "significantly higher in trees than in other life forms."

What it means
In light of the results of their several analyses, Marty and BassiriRad conclude "it is reasonable to speculate that, if parental eCO2 significantly affects regeneration success, and if such effects are species- and genotype-specific, the potential for ecological and evolutionary consequences is immense."

Baskin, C .C. and Baskin, J.M. 1998. Seeds: Ecology, Biogeography, and Evolution of Dormancy and Germination. Academic Press, New York, New York, USA.

Clauss, M. and Venable, D. 2000. Seed germination in desert annuals: an empirical test of adaptive bet hedging. The American Naturalist 155: 168-186.

Edwards, G.R., Clark, H. and Newton, P.C.D. 2001. The effects of elevated CO2 on seed production and seedling recruitment in a sheep-grazed pasture. Oecologia 127: 383-394.

Fenner, M. 1985. Seed Ecology. Springer-Verlag, New York, New York, USA.

Garwood, N. 1983. Seed germination in a seasonal tropical forest in Panama: a community study. Ecological Monographs 53: 159-181.

Grime, A.J.P., Mason, G., Curtis, A.V., Rodman, J. and Band, S.R. 1981. A comparative study of germination characteristics in a local flora. Journal of Ecology 69: 1017-1059.

Harper, J.L. 1977. Population Biology of Plants. Academic Press, London, United Kingdom.

Leishman, M.R., Sanbrooke, K.J. and Woodfin, R.M. 1999. The effects of elevated CO2 and light environment on growth and reproductive performance of four annual species. New Phytologist 144: 455-462.

Menges, E.S. 1991. Seed germination percentage increases with population size in a fragmented prairie species. Conservation Biology 5: 158-164.

Radford, I.J. and Cousens, R.D. 2000. Invasiveness and comparative life-history traits of exotic and indigenous Senecio species in Australia. Oecologia 125: 531-542.

Steinger, T., Gall, R. and Schmid, B. 2000. Maternal and direct effects of elevated CO2 on seed provisioning, germination and seedling growth in Bromus erectus. Oecologia 123: 475-480.

Reviewed 27 August 2014