The Effects of Acidic pH on Photosynthesis

• All green plants create energy from the sun from the process of photosynthesis.detail de feuille image by choucashoot from Fotolia.com
  
  Photosynthesis is the process by which green plants convert light into energy within individual cells. This energy is stored within the leaves of the plant and serves as food for secondary consumers. Abnormal pH values can make a difference in a plant's ability to conduct photosynthesis. This is of significance, in view of acid rain due to pollution in many parts of the United States and its subsequent effect on trees and other plant life.
  
  

Lower Oxygen Output

• Photosynthesis releases oxygen as a byproduct even as humans release carbon dioxide. Acid pH results in less oxygen production from plants.Tiges image by St??phanie Detroy from Fotolia.com
  
  In a published research paper by honors students Sara Schrock, Alex Vallar and Jan Weaver entitled "The effect of acidic conditions on photosynthesis in two aquatic plants," the researchers state that acid rain has been demonstrated to have long-term effects on terrestrial vegetation.
  
  They designed an experiment documenting that observation, which involved lowering the pH in a test tube that contained a neutral solution and aqueous plants, Cabomba carolinia and Elodea, by using acetic acid (vinegar). They discovered that the oxygen output of the samples with the acidic pH was significantly lower than that of the control group with a neutral pH. Oxygen is a biproduct of photosynthesis.
  
  

Carbon Dioxide Concentrations Decline

• Carbon dioxide concentrations also decline in the process of photosynthesis due to acidic pH, according to a study by D.L. Qiu, X.H. Liu and S.Z. Guo entitled "Effects of Simulated Acid Rain on Longan Photosynthesis," as reported in ISHS Acta Horticulturae and the International Symposium on Litchi and Longan. The researchers tested the effects of acid pH (lower than 3.5 in this study) on longan fruit trees (longan trees are native to China).
  
  

Increase of Stomatal Conductance and Dark Respiration

• Acid rain can disrupt the delicate balance of nature and can lead to higher carbon dioxide concentrations in the atmosphere.forest image by Andrey Rakhmatullin from Fotolia.com
  
  Stomatal conductance (Cs), which is defined as the rate of passage of water vapor or carbon dioxide through the stomata, or the small pores of the plant, increased when the leaves were treated with artificial acid rain. Dark respiration, where carbon dioxide is expired by the plant rather than oxygen, also increased with the reduced pH.