Impact of Simulated Acid Rains on Nitrogenase Activity in Peltigera Aphthosa and P. Polydactyla

1985 ◽  
Vol 17 (1) ◽  
pp. 27-31 ◽  
Author(s):  
R. P. Fritz-Sheridan
Keyword(s):  
Nitrogen Fixation ◽  
Acid Rain ◽  
North American ◽  
Nitrogenase Activity ◽  
Simulated Acid Rain ◽  
Complete Inhibition ◽  
Simulated Rain

AbstractTwo ubiquitous diazotrophic North American lichens, Peltigera aphthosa and P. polydaclyla, were subjected to simulated acid rain. Both lichens exhibited a 50% reduction in nitrogen fixation at pH 5, 80% reduction at pH 4 and complete inhibition at pH 2. Nitrogen fixation was zero after 20 days exposure to simulated rain at pH 3 and zero after fourdays at pH 2.

Influence of simulated acid rain on the flowering dogwood (Cornusflorida) leaf surface

1994 ◽  
Vol 24 (5) ◽  
pp. 1058-1062 ◽  
Author(s):  
Daniel A. Brown ◽  
Mark T. Windham ◽  
Robert L. Anderson ◽  
Robert N. Trigiano
Keyword(s):  
United States ◽  
Acid Rain ◽  
Leaf Surface ◽  
Simulated Acid Rain ◽  
Eastern United States ◽  
Flowering Dogwood ◽  
Simulated Rain ◽  
Decreasing Ph ◽  
One Year ◽  
Scanning Electron

Acidic rainfall has the potential to influence anthracnose incidence and severity in flowering dogwood (Cornusflorida L.) of the eastern United States. One-year-old, nursery-grown flowering dogwood seedlings were exposed to 1 cm of simulated rain 10 times over a 42-day period in 1990. Simulated rains were composed of a mixture of salts typical of ambient rainfall in the eastern United States and pH was adjusted to 5.5, 4.5, 3.5, and 2.5 with sulfuric and nitric acids. Samples were cut from the leaf tip, margin, and midvein of rain-treated trees and prepared for scanning electron microscopy. Cuticular cracking, desiccation, and erosion of trichome surfaces was observed in response to acid rain treatment. Increased degradation of dogwood trichomes was observed with decreasing pH for all samples. Cuticular erosion due to acid rain has the potential to predispose dogwoods in the eastern United States to anthracnose caused by Disculadestructiva sp.nov. (Red.) and an unnamed Discula sp.

Effects of ozone and acid rain on white pine (Pinus strobus) seedlings grown in five soils. II. Mycorrhizal infection

1988 ◽  
Vol 66 (8) ◽  
pp. 1510-1516 ◽  
Author(s):  
Hans F. Stroo ◽  
Peter B. Reich ◽  
Anna W. Schoettle ◽  
Robert G. Amundson
Keyword(s):  
Acid Rain ◽  
Nitrogen Concentration ◽  
Pinus Strobus ◽  
Simulated Acid Rain ◽  
Mycorrhizal Infection ◽  
White Pine ◽  
Available Nitrogen ◽  
Mycorrhizal Roots ◽  
Simulated Rain ◽  
Highly Correlated

Mycorrhizal infection of white pine (Pinus strobus L.) seedlings was measured after 4 months of exposure to simulated acid rain and ozone, applied either alone or in combination. Increasing rain acidity consistently reduced the number of mycorrhizal short roots. In general, infection decreased linearly versus rain pH. Plants exposed to simulated rain at pH 3.0 had approximately 20% fewer mycorrhizal roots than plants exposed to pH 5.6 rain. The decrease in the number of mycorrhizal roots was a result of decreases both in the number of short roots available for infection and in the percentage of roots infected. Ozone had no effect on mycorrhizal infection if applied 3 alternate days/week at concentrations ranging from 0.02 to 0.14 ppm. However, there were significant changes in infection in plants exposed to ozone for 5 days/week. There was no evidence for an interaction between the two pollutants. Percent mycorrhizal infection was highly correlated with seedling nitrogen concentration across all soil types and rain treatments. These observations suggest that increases in available nitrogen may have been largely responsible for the observed effects of acid rain on mycorrhizae.

Effects of simulated acid rain on needle wettability and rain retention by two Sitka spruce (Piceasitchensis) clones

1991 ◽  
Vol 21 (5) ◽  
pp. 694-697 ◽  
Author(s):  
K. E. Percy ◽  
E. A. Baker
Keyword(s):  
Contact Angle ◽  
Ion Exchange ◽  
Acid Rain ◽  
Surface Properties ◽  
Sitka Spruce ◽  
Contact Angles ◽  
Simulated Acid Rain ◽  
Sodium Fluorescein ◽  
Simulated Rain

The effect of simulated rain acidity (pH 2.6, 3.4, 4.2, and 5.6) on wettability and rain retention was investigated for elongating needles on stecklings of two Sitka spruce (Piceasitchensis) (Bong.) Carr) clones over an 11-week period. There were highly significant differences in contact angle between pH treatments, clones, and sample dates. Contact angles on needles of both clones exposed at pH ≤ 4.2 were significantly smaller than those on needles exposed at pH 5.6. Needles from both clones exposed to simulated rain at pH ≤ 4.2 retained significantly more simulated rain containing sodium fluorescein. These changes to needle surface properties following realistic exposure to simulated acid rain could have important consequences for processes occurring at the phylloplane, such as ion exchange.

Effect of Simulated Acid Rain on Gas Exchanges of Three Compositae Invasive Plants

2013 ◽  
Vol 48 (2) ◽  
pp. 160-167
Author(s):  
Song Liying ◽  
Ke Zhanhong ◽  
Sun Lanlan ◽  
Peng Changlian
Keyword(s):  
Acid Rain ◽  
Invasive Plants ◽  
Simulated Acid Rain ◽  
Gas Exchanges
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