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Green house set up in 2010.
Overview:
This experiment examined the direct foliar effects of acute,
short-term exposure to 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) was sprayed onto the above-soil
foliage of 7 day old seedlings once daily to completely wet the
foliage and moisten the soil surface for a total of 18 daily
applications. The controls were similarly treated with plain
tap water (~pH 6.8 at initiation of treatment phase). The seedlings
were watered to soil saturation once daily with tapwater either
several hours before or after treatment application.There were
18 replicates (pots of seedlings) per species per treatment group
in 2010. The plants were measured for stem and leaf lengths,
dry biomass per plant, the proportion of plants that exhibited
any damage (dead cells, lesions, spotting, etc.), and the percent
leaf area exhibiting damage. Leaf wettability was examined by
placing drops (20-30 ul) on the leaves and observing retention
and drop shape. Leaf samples were also prepared and viewed using
a scanning electron microscope to document microscale effects
(view
poster of 2008 experiment SEM images).
Seedling
Establishment 2010 (1/7/10 - Day 1 SAR application)
Day 7 of SAR Applications
(1-14-2010)
Day 13 of SAR Applications
(1-19-2010)
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SAR applications were stopped
on Jan 24th, 2010.
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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.
pH 2 sunflower with true leaf petiole
growing from cotyledon position on stem. |
Abnormal leaf development in sunflowers.
These were seen in pH 3.5 and control. |
Same as above. |
Sunflower pH 2 stem lesions day 19. |
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Scanning electron micrograph of acid burn
on a sunflower leaf treated with pH 2 simulated acid rain.
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2010 Bates College
Modified on 1-15-2010 GA
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