Douglas Fir Trees Lab Report

Effect of pH change on Douglas Fir trees
Question: Does the acidity of rain affect a douglas fir tree? Hypothesis: If we spray 3 separate douglas fir branches with 3 different pH types of liquid; pH 7, pH 6.8, pH 4, then the branch sprayed with pH 4 water will loose/brown the needles the quickest because pH 4 water is highly acidic. Background: Douglas Fir trees usually prefer pH precipitation of 7-6, the pH of 7 is perfect pH water, 6.8 is normal pH of precipitation in Oregon, pH 4 is very acidic. I know that acid rain can be very harmful to an array of plants, I’ve also heard that we may have acid rain falling in the gorge.
List of Materials: 3 branches of douglas fir trees, lab coat, goggles, 3 normal plastic bags, 1 heavy duty bag, gloves, three different spray bottles filled with three different pH level liquids; pH 7, pH 6.8, and pH 4
Steps: …show more content…
Step 6: Record the effects Step 7: Repeat steps 4-6 six more times

Variables:
IV: pH of the liquid DV: Needles lost / Color of needles CV: Amount of sprays, Days sprayed

Data Collection:
Liquids
Days 1 2 3 4 Weekend 5 pH - 7
0
1
1
1
Weekend
7 pH - 6.8
0
1
50
70
Weekend
70 pH - 4.0
0