Impact of simulated acid rain on microbial respiration, biomass, and metabolic quotient in a mature sugar maple (Acersaccharum) forest floor

1996 ◽  
Vol 26 (8) ◽  
pp. 1446-1453 ◽  
Author(s):  
Chandini M. Thirukkumaran ◽  
Ian K. Morrison

Effects of simulated acid rain on forest floor microbiological processes were investigated in an old-growth sugar maple (Acersaccharum Marsh.) woods at Turkey Lakes Watershed, northern Ontario, Canada. Sulphate and NO3− in ambient precipitation received on four replicate plots were augmented with additions of dilute (0.02 N) H2SO4 and HNO3, applied alone and in combination periodically during the growing seasons of 1993 and 1994. The equivalent load of SO42− applied in the present experiment was ca. 6 times that in ambient precipitation in the H2SO4-only treatment and half that in the combined treatment over the study period. In situ soil respiration measured during the summer and fall of 1994 showed no adverse effects of acid treatment. In the laboratory, soil microbial respiration, biomass (as determined by substrate-induced respiration), and microbial biomass carbon: organic carbon (Cmic/Corg ratios were significantly depressed in the L or FH layers of the forest floor when H2SO4 was applied alone or in combination with HNO3. No effects of HNO3 were detected when applied alone. Microbial respiration, substrate-induced respiration, and Cmic/Corg ratios were significantly correlated with forest floor pH. Microbial metabolic quotients (respiration:biomass ratios) were not adversely affected by any of the treatments. The observed deleterious effects of H2SO4 application under experimental conditions suggest the possibility of adverse effects in the field over the long-term.

2012 ◽  
Vol 610-613 ◽  
pp. 181-185 ◽  
Author(s):  
Xiao Hua Duan ◽  
Xiao Fei Hu ◽  
Fu Sheng Chen ◽  
Ze Yuan Deng

The effects of simulated acid rain and aluminum (Al) addition on growth and photosynthesis physiology of tea plants (Camellia sinensis L.) were studied with tea seedlings in a hydroculture experiment. Results showed that the growth of tea plant, chlorophyll content, and photosynthesis (Pn) of tea leaves were better in the treatments of suitable Al addition (10 mg/L and/or 20 mg/L) than the treatments without Al addition and higher Al addition (30 mg/L). The growth of tea plant increased with increasing acidity of acid rain, while the leaves of tea plant showed more chlorophyll content and higher Pn at the treatment of pH 4.0 than pH 5.0 and pH 3.0 acid solutions. The growth of tea plant, chlorophyll content and Pn were the best at the combined treatment of suitable Al addition (10~20 mg/L) and moderate acidity of acid rain (pH 4.0), while the slowest at the combined treatment of 30 mg/L Al and pH 3.0 acid rain. These results suggested that suitable Al and moderate acidity of acid rain are helpful to increase tea production by increasing photosynthesis capacity.


1990 ◽  
Vol 68 (10) ◽  
pp. 2292-2300 ◽  
Author(s):  
C. N. N'soukpoé-Kossi ◽  
R. Bélanger ◽  
S. Keilani ◽  
H. Proteau ◽  
P. Boivin ◽  
...  

Photoacoustic spectroscopy was used to monitor acid damage to photosynthesis by measuring photosynthetic O2 evolution in leaves from com and sugar maple plantlets. For 2 months the seedlings were treated with simulated acid rain either by spraying the leaves or by watering the soil at different pH levels. The results indicated a decline of photosynthetic oxygen evolution as the pH of the foliar application of simulated acid rain decreased. The reduced photosynthetic activity was sometimes followed by depigmentation (below pH 3.5). For plantlets treated by watering the soil with an acid mixture, the results showed an increase in the growth rate at higher acidity levels without effect on the photosynthetic activity. All corn seedlings from seeds that germinated in media of different pH levels showed the same photosynthetic activity regardless of the pH, as measured by photoacoustic spectroscopy, but the growth rate was higher at lower pH values than at higher pH values. These results clearly indicate the importance of acid damage to photosynthesis at the foliar level, and the ability of photoacoustic spectroscopy to assess forest decline in its early stages. Key words: photoacoustic spectroscopy, photosynthesis, corn, maple, acid rain, oxygen evolution.


2010 ◽  
Vol 56 (No. 6) ◽  
pp. 268-273 ◽  
Author(s):  
T. Filep ◽  
T. Szili-Kovács

In the paper we investigate the effect of liming on the microbial biomass carbon (MBC) in pot experiments during two vegetation periods. There was also another goal to get better understanding of the role of dissolved organic matter (DOM) and its quality on microbial processes. Pot experiments were carried out on two acidic soils. Liming material treatment was 0, 1, 2, 3 g CaCO<sub>3</sub>&thinsp;/kg soil (corresponding with 0, 1.4, 2.8, 4.1 t CaCO<sub>3</sub>&thinsp;/ha, respectively). On both soils, 3-3 soil samples were taken for two growing periods and the substrate-induced respiration (SIR), dissolved organic carbon and nitrogen (DOC and DON), and soil pH were determined from the soil samples. The SIR can be used to characterize the active biomass within the total microbial biomass. Liming was found to increase soil respiration and consequently MBC in the first year of the experiment, but at the maximum lime rate these values stagnated or declined in many cases on each soil. In the second year, the effects of treatments were much lower both on Kisv&aacute;rda and on Ny&iacute;rlugos soils. Under the given experimental conditions, when the DOC/DON ratio rose to above 30&ndash;40, disturbances appeared in N supplies to microorganisms. The N content of the easily mineralisable organic matter in the soil became so low that it inhibited the reproduction of the microorganisms.


2017 ◽  
Vol 41 (5) ◽  
pp. 584-595 ◽  
Author(s):  
Noreen Khalid ◽  
Ali Noman ◽  
Muhammad Aqeel ◽  
Naila Hadayat ◽  
Sumreen Anjum

Sign in / Sign up

Export Citation Format

Share Document