1) What type of instrument and methods could I use to determine which type of tree resin/sap is most flammable?
2) How could I determine how much drier a beetle kill tree is than a tree that died of natural causes? (Assuming the trees are of the same age and location)
Answer from Posse Member Dave McKenzie:
The bomb calorimeter is the only method I know of for getting this sort of data. There may be others. You could try some of the departments around campus, but I don't think you'll have much luck. My lab mate was trying to use one and would have had to go Denver I believe it was.
1) What type of instrument and methods could you use to determine which type of tree resin/sap is most flammable?
I can't think of any particular instrument that would be used for this, but I have an idea. You could collect similar amounts of sap and put them in some sort of metal container (beer cap or soda can bottom). Then, apply heat from a constant and repeatable heat source (long-handled lighter for example). You would measure the amount of time needed for the sap to begin to burn on its own. Never having done this, I'm not sure how much it would take or whether or not it would even work. You may have to move up to a propane torch (available for about $30 at the local hardware stores) for more heat. I'm sure you could find some sort of oven or candy thermometer that you could then apply the same amount of heat to in order to get the approximate temperature. As a forest scientist the time a particular sap takes to burn is just as interesting as which is more flammable because in forest fires the duration and intensity of the flames both play a role in tree mortality.
2) How could you determine how much drier a beetle kill tree is than a tree that died of natural causes? (Assuming the trees are of the same age and location)
This one is pretty manageable. You could take needles or wood in equal amounts (volumetric) from several trees. For this, wood would be easier because it's hard to calculate the volume of needles without getting them wet. Use a scale to measure the mass of each sample. You will want to use a scale that measures in grams and goes out to several decimal places. I think thousandths would be the minimum, but use what you can get your hands on. Weigh the samples as soon as you can after cutting them. Then, put them in a drying oven set to probably 90 degrees C. Dry them for several days, taking a mass measurement every other day. Once the mass levels off you can assume the samples are totally dry. The difference in mass between the fresh sample and the dry sample is water (and other volatiles) that evaporated through drying. If you use several samples (as many as you can handle actually), you will be able to come up with an average difference, making your study much better. You could use needles for this, but you would have to calculate the volume after you dried the samples. Even with the wood, you will still want to correct for exact volume. In the end you want to be able to compare percent moisture loss. For example: "The living tree was 15% moisture by mass, the beetle killed tree was 8% and the naturally killed tree 12%. Thus, the beetle killed tree was the driest."
I hope this helps. Let me know if you have any other questions.
I want to compare the "energy amount"/ calories of leaves when they are turning different colors so does a green, yellow, or red leaf of the same tree have more calories? I know that different color wavelengths of light correspond to different amounts of energy, but does the color also correlate to different amounts of energy?
Answer from Posse Member Dave McKenzie:
"Does a green, yellow, or red leaf of the same tree have more calories?"
This is a valid question that could be answered if the student had access to a bomb calorimeter, which measures the number of calories in a sample by burning it. The caloric content in the leaves of different colors likely would change because the chemical composition of the leaves is changing with different colors. The appearance of red/orange/yellow is the manifestation of the reduction of chlorophyll concentration in the leaf that allows those other colors (chemicals) to be seen. They are always there, but the chlorophyll (green) covers them up. Chlorophyll provides certain chemicals that the other compounds do not. Therefore, the caloric content would change just as it does when we alter the chemicals in our own food (although the use of the word ‘calorie' is slightly different). I do not know of a way to test the caloric content of leaves without a calorimeter. I would expect that green leaves have the highest calorie content because they have the most ‘stuff' in them (chlorophyll). Many species pull materials out of leaves in the fall to reuse next year.
"Different color wavelengths of light correspond to different amounts of energy, but does the color also correlate to different amounts of energy?"
The actual color of the leaf has nothing to do with the caloric (energy) content of the leaf. The color of the leaf is simply the light that is reflected (green/yellow/orange/etc) from the full spectrum after other wavelengths have been absorbed (blue/violet/etc). The amount of energy hitting the leaf (this time measured in photons) changes with season because of the orientation of the earth. The amount is not affected by the material it hits. We must separate these two forms of energy. Photons are emitted from the sun and absorbed by the leaf. The leaf then uses that photon energy to convert raw materials to plant matter. It is the plant matter that is measured in calories. I should return to my first sentence in this paragraph. The energy content of the leaf would vary in terms of calories, but this is not a direct result of color. It is a result of chemical composition (which also affects light reflection and thus, color).
I hope this answers your questions. If you need some follow up or clarification, please let me know.