Green house set up in 2013
Overview: This experiment examines the direct
foliar effects of acute, short-term exposure to simulated acid
rain (SAR) on seedlings of three domesticated plant species:
sunflower, radish, and clover. Simulated acid rain of pH 3.5
and pH 2 (tapwater acidified with a 2:1 molar ratio of sulfuric:nitric
acids) is sprayed onto the above-soil foliage of 10 day old seedlings
once daily to completely wet the foliage and moisten the soil
surface for a total of 20 daily applications. The controls are
similarly treated with plain tap water (typically ~pH 6.8-7.4).
The seedlings are watered to soil saturation once daily with
tapwater either several hours before or after treatment application.There
are 18 replicates (pots of seedlings) per species per treatment
group in 2013. Upon completion of the treatment phase, the plants
are measured for stem length and leaf area, dry biomass per plant,
the proportion of plants that exhibit any damage (dead cells,
lesions, spotting, etc.), and the percent leaf area exhibiting
damage. Leaf wettability is examined by placing drops (20-30
ul) on the leaves and observing retention and drop shape (contact
angle). Leaf samples are also prepared and viewed using a scanning
electron microscope to document microscale effects on tissues,
surface structures, and epicuticular wax (view
poster of 2008 experiment SEM images).
Seedling
Establishment 2013 (1/22/13 - Day 1 SAR application)
Day 14 of SAR Applications
(2-4-2013)
Click the individual
images to see larger overview of plants in each treatment group.
| CLOVER |
 |
| RADISH |
 |
| SUNFLOWER |
 |
| DAY 14
pH 2.0 Leaf damage details |
 |
Appearance at data collection
(2-10-2013)
SAR applications were stopped
on Feb 10th, 2013.
Click the individual
images to see larger overview of plants in each treatment group.
Droplet formation images
ARCHIVAL PHOTOS OF TYPICAL
EFFECTS OF SIMULATED ACID RAIN IN THIS EXPERIMENT
Following are detail shots
of the typical physical effects of the acid treatment on the
pH 2 plants. These photos are from various years, but typify
direct effects we see routinely in this experiment.
