Green house set up in 2009.
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 11 day old seedlings once daily to completely wet
the foliage and moisten the soil surface for a total of 20 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
20-23 replicates (pots of seedlings) per species per treatment
group in 2009. The plants were measured for stem and leaf lengths,
dry biomass per plant, total chlorophyll content (radish sunflower
only in 2009), 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 2009 (2/1/09 - Day 10 )
Day 16 of SAR Applications
(2-17-2009)
CONTROLS
pH 3.5
pH 2.0
Droplet formation images
SAR applications were (will
be) stopped on Feb 22nd, 2009.
ARCHIVAL PHOTOS OF TYPICAL
EFFECTS OF SIMULATED ACID RAIN IN THIS EXPERIMENT
