DUCKWEED ESSAY (BIOLOGY)
The Duckweed Report
In this investigation i was researching the growth rate of the population of duckweed. I started out with 30 duckweed in a small cup. The point of the experiment was to watch the growth of the duckweed and record the data, while also taking note of what is happening with the water, cup and any other variable. After brief research of duckweed, i hypothesized that the duckweed would grow at a fast rate,considering that i started with 30 duckweed. Something that i did not think about before the experiment was the cup size. I did not think about how the small cup size would affect the population growth rate of the duckweed. I ended up learning that the duckweed did grow fast, but the small size of the cup has a carrying capacity, and when it reached that is when i would see a decline in the population, and it would go back up to the carrying capacity.
Duckweed is a small flowering plant, that can be found growing on lakes. They are an invasive species, this means that they grow very fast and can takeover a lake in a short period of time. Duckweed can grow on any lake, wetland or pond. It is not specific to any particular ecosystem. They are one of the smallest flowering plants, but you can barely see their little white flower. One way the the plant is spread around to different bodies of water is, when birds get it suck to them, and carry it from one place to another. Since it grows so fast it does not need a lot to begin with for it to blossom into a large community of duckweed.
I expected the duckweed to grow a large amount in the six weeks that we were letting it grow. The independent variable was the amount of weeks we let it grow, and the dependant variable was how many duckweed has grown. I thought that the population of duckweed would more than double in size, starting with 30 i expected to have up to 80 duckweed at the end of the 6 weeks.
The materials that were used for this experiment were: 2 cups, 30 duckweed for each cup, light bank, and loops for counting the duckweed. First you fill the cups 2/3rds with spring water, add 30 duckweed to each cup, label them and record the population growth each week, while keeping them under the light bank
9.16.16- duckweed plant stems are all grown out,starting to get stuck together
9.30.16- i thought the duckweed was just dying but some of them were getting stuck together, but were ready to sprout into more.
My duckweed, showed steady growth throughout the six weeks. There were some moments of the population going down, but it ended on the highest number of the whole six weeks. I believe that the duckweed did not reach the carrying capacity because at the end of the experiment the duckweed seemed to keep growing and did not seem like it was slowing down yet. Compared to other graphs, the growth seems to be moving faster than the other groups. I believe this is because i started with more duckweed than them and it had more chances to grow and not let the population get to small.
The growth of my duckweed compared to my hypothesis, was not super far off. I expected the duckweed to grow to great numbers exceeding 70, but it was only able to grow up to 65. My duckweed did not reach carrying capacity, it was still on a positive incline during the last week. The most important limiting factor in this was the cup size. It largely restricted the area that the duckweed was able to grow in.
If i were to take my duckweed population to a lake, it would have a better time growing. The carrying capacity has drastically expanded, and the duckweed would be in a natural habitat that it can thrive in. Adding fertilizer to the habitat in the cup would have sped up the growth but i think it would still hit the carrying capacity much quicker. This whole experiment showed me about how a habitat can sustain itself by controlling populations with carrying capacity. Population growth has many limiting factors, and will most likely not take over the habitat.
Sources
this is the budget for my pretend character in my economics class
ECONOMICS CHARACTER BUDGET
GETTING RICH ECON PRESENTATION
https://docs.google.com/a/alamedaclc.org/presentation/d/1v0KiN8mhbpW_zZdp9kLaLw6FzLLe38PJsAe-3-mncKY/edit?usp=sharing