Sulfur dioxide effects on net photosynthesis and cumulative carbon dioxide fixation in red spruce stands.

摘要

he general objective of this thesis is to quantify the effects of ;Rates of net photosynthesis and stomatal conductance of twigs were measured under field conditions before and after twig detachment on clear midsummer days. It was found that these variables did not change significantly within 6 minutes after twig detachment. Thereafter, the rate of net photosynthesis and stomatal conductance decreased.;Foliage of mature red spruce trees was exposed to ;Net photosynthesis and dark respiration of foliage on red spruce trees downwind from a coal-burning power plant were determined. Sulfur dioxide effects on needle surface wax, foliage elemental concentrations and surficial elemental distribution were also noted. It was found that rates of net photosynthesis of current-year foliage were not significantly affected by low rates of ;A canopy-level model was developed to calculate cumulative ;This research provides a bridge to quantify the effects of