Mediterranean natural forest living at elevated carbon dioxide : soil biological properties and plant biomass growth

The effects of elevated atmospheric carbon dioxide (CO sub(2)) on soil biological process in a natural Mediterranean forest ecosystem were studied. Annual production of new leaves and shoots and root mass produced per unit of soil were measured, as were soil biochemical parameters (microbial C biomass, microbial respiration, dehydrogenase, acid phosphatase, and others), inorganic nitrogen and soluble phosphorus, and CO sub(2) concentration inside open-top chambers enclosing clumps of woody vegetation. Seasonal patterns were observed in some parameters in response to climate, soil nutritional status, and plant physiology. Microbial responses to enriched CO sub(2) were observed only at the beginning of the study; the effects diminished with time-results that agree with those from other studies.