USC Dana and David Dornsife College of Letters, Arts & Sciences

Today our professor, Lisa Collins, visited and we worked mostly on setting up the lab work for the colorimetric analysis of ammonia. We had 26 test tubes prepared, 2 for each of our 13 samples (10 soil samples plus 3 duplicates). Miller and I labeled each test tube in a systematic way (1-1, 1-2, 2-1, 2-2), I did all the 1s, while he did all the 2s. Then I used the pipette to retrieve 3.0 mL of the soil sample from the erlenmeyer flasks that we had created earlier on July 18, and inserted into the test tubes.

Sabrina prepared another tray of 24 test tubes with the stock and blank solution. For each of these 50 test tubes, we added 400μL of salicylate catalyst. We created another mixed reagent that was 1 part chlorox and 9 parts alkaline-citrate reagent, which was equivalent to 3mL of Chlorox and 27mL of alkaline-citrate reagent. This would just be enough for the 50 test tubes that each needed 600 μL of the mixed reagent.

We actually didn’t have chlorox, so Dan and Miller had to drive to Two Harbors to get it. Then we added the mixed reagent to the test tubes. However, on the first two samples, we realized something went really wrong. Immediately after adding the alkaline-citrate, the sample precipitated, which was not supposed to happen. With the samples solidifying we are unable to run the samples through spectrometer and get an accurate reading. We had to quickly resort to a new protocol. The revised plan was to add 120mL of phenol, 120mL of sodium nitroprusside, and 300mL of chlorox solution to each of the 50 samples. The team was in full gears as we all took on individual tasks: preparing the reagents, pipetting solutions, sealing the samples with parafilm, and turning the test tubes upside down. Lisa even gave us a hand. Even with all this help we were barely able to make it to lunch.

During lunch we met up with Professor Jim Haw, who is the head of the Environmental Studies department. He was also my professor in quite a few classes. We told him how we sighted a rattlesnake up on our trail, and he became quite interested on hiking it. Unfortunately, he had a meeting, so he couldn’t do it. After lunch, we debriefed with Lisa about the teams’ aims and goals for our internship. We have about 3 weeks left, and we needed to prioritize on our deliverables. Once we finished, we went back to lab. We hoped that by the time we came back from lunch, the samples would have reacted with the solutions and changed color. It did not. Without any reaction, we aren’t able to do any analysis on the experiment. So our nitrogen testing was not successful.

For more pictures, click here: Day 46 Soil Analysis

The week so far has been extremely fun and exciting. It was packed with new activities and I really appreciated the break in the routine. We had an early start as we headed out to revisit Middle Ranch and work with Peter Dixon, the native plant nursery supervisor at the James H Ackerman Nursery. For the first half of the day, we worked on transplanting Catalina Island currants: Ribes viburnifolium, into bigger pots. These were native species in the gooseberry family. We transplanted over 100 of them, completing 6 trays. Before we started, Peter demonstrated the transplanting process. We began with filling the larger pot with soil, about 2/5 of the way. Then, we massaged the outside of the smaller pot to loosen it, and gently turned the pot over to remove the plant. Once we had the plant in our hands, we carefully “tickled” the bottom part to open up the roots. It was then time to transplant the currant into the bigger pot. We packed it into the soil. Peter advised us not to bury the plant too deep and to actually expose the root near the surface to prevent fungus disease. We continued to add more soil, compacting it around the edges and in the center, until it was firm. Then we placed the transplanted pots into a wheeling cart and watered it 3 times back and forth. It was important to get them soaked. Then we wheeled the cart into the nursery and placed the pots on the shelves. On the way back we got another tray of plants. We transplanted until we completed all 6 trays.

The second half of the day was dedicated to collecting seeds. We drove towards Avalon and stopped at two different sites to collect seeds for the purple needle grass (Nasella pulchra) and the silver lotus (Lotus argophyllus var. argenteus) respectively. We tied plastic bags on our pant loops to put the seeds in there. The purple needle grass was a fine, long brown stalk that swayed elegantly with the wind. We found them in an enclosed area where most of the seeds had already been released. Because the area belonged to the Conservancy, we could only take at most 10% of the plant. We had to leave some grass to regenerate. I had a difficult time differentiating the purple needle grass from other grasses, especially since the entire enclosed area was all grassland. I frequently got the purple needle grass confused with the ripgut grass. For me, I have to touch the seed to figure it out. The ripgut was harsher at the end; it almost felt sticky to me. Once we found a stalk with seeds, we held the stalk and pull the seeds in one quick upward moment, like a zipper action, and the seeds fell off easily.

We went further along Avalon, near the Catalina Island Marine Institute at Toyon Bay to gather the silver lotus. The site had an abundance of the plant. The silver lotus was more distinguishable than the purple needle grass. It was kind of weedy and had a yellow, brownish flower. The browner lotus meant the seed was ripe. We pulled out horn-like petals, which crumbled easily at our touch, and opened one with our nails. It was extremely difficult, but with much persistence I was able to pry it open and discover the tiniest seed I’ve ever seen. It looked similar to cricket turd. It was such an adventure going around the canyon to collect these seeds.