How does rising atmospheric CO2 affect marine organisms?

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Shade Tolerance in Woody Species: Does It Enhance or Hinder Growth Response to Elevated CO2?
Kerstiens, G.  2001.  Meta-analysis of the interaction between shade-tolerance, light environment and growth response of woody species to elevated CO2Acta Oecologica 22: 61-69.

What was done
The author conducted a literature review of 24 studies that reported 74 woody-plant growth responses to elevated CO2.  Data were analyzed and grouped according to whether the studied species were deemed to be shade-tolerant or shade-intolerant.  Evaluations were based on growth response to a doubling (700 ppm vs. 350 ppm) of the atmospheric CO2 concentration.

What was learned
Elevated CO2 increased the relative growth response of shade-tolerant woody species by an average of 51%, while it increased the relative growth response of shade-intolerant species by approximately 18%.  Thus, although typically exhibiting slower growth rates, shade-tolerant species exhibited greater CO2-induced increases in biomass than more rapidly growing shade-intolerant species.

What it means
As the CO2 concentration of the air increases, shade-tolerant woody plants will likely increase their biomass by close to three-fold more, on a percentage basis, than shade-intolerant species.  This advantage should provide for greater seedling survival and establishment of shade-tolerant plants in the types of low-light environments that prevail on forests floors beneath tall and dense forest canopies.

Reviewed 20 February 2002