The movie took place at Hubbard Brook National Park, which is the site of many chemical tests on the soils and many watersheds. The movie spoke about how there were watersheds all along the hills in the park. This made it easy for scientists to set up their experiments and test the chemicals that were in the water and being transferred around the area. The main experiment that was talked about involved the deforestation of the area surrounding the watershed. After deforestation herbicides were used and they highly increased the nitrate levels in the water and soil. This showed that use of herbicides is harmful and should not be condoned in woodland areas.
They talked about the loss of Calcium in the dirt, stating that "It is possible that the calcium retreated into the trees because they needed it to grow," further testing would be needed to confirm that theory. If the nitrates keep rising and calcium levels keep depleting the health of the soil will go down very much because calcium is vital to healthy soil and nitrates, when in too much abundance, can be harmful. The scientists tested magnesium levels as well, this being very important to plant growth. The levels of these minerals in the soil can be disturbed by both natural changes and human interaction. The tough part is knowing how much changes naturally and how much is human interaction.
The air tester was really cool because not only was it directly hooked up to a computer to find data it also was connected to wind mills and humidity testers. This created an experiment that took into account many variables that could change the levels daily and make sure the data was as exact as possible. The air tester had a module that tested minerals in the air, a module that tested changes in minerals in the air, and windmills and humidity detectors to test the effect of winds and water vapor on the mineral levels.
After the movie we did an experiment testing soils. This involved feeling the soils and using our senses to try to find which soils fit descriptions and how water effected that feeling. We tested one dirt sample that felt very grimy at first but when wet became very soft and gooey. Another was rough and almost solid when it was dry but when we wet it it fell apart and was rough but not blocky, it was sandy almost.
I had the misfortune, and stupidity, of showing up late and missing the original screening of the film. I was lucky because Alan let me take the video in order to watch it on my own time. It was interesting and short which made it easy to remember specifics. What really stood out to me about the movie was the wide range of materials used to test levels of minerals in water, soil, and even dry minerals in the air. The deep thorough testing that goes on using countless machines and tests makes the watersheds very accurate and very reliable. The testing went on in air, land, and water helping the scientists truly understand what is making the difference and how humans are affecting it. Overall I was very interested and the food was delicious. Very enjoyable.
