Group Blog Post: Biosphere

Group Blog Post: Biosphere

Team Members:Hazel Arman, Greyson Hamilton, Michelle Le, Eloina Rodriguez

Figure 1:Week one of the Biosphere with soil brimming the top of the jar.

Figure 2: The Biosphere during week 6 with dense algal growth.

Questions:

• Why did you choose to include the organisms that you put in your biosphere?

We wanted to balance the ecosystem we were creating, we did not want too many heterotrophs because they would eat the plants at a rate in which they could not cope/recover. The plants were the main oxygen generators in this environment had the heterotrophs finished them off, the eco-sphere would not have made it long. We also didn’t want to introduce too much photosynthetic microbes into the biosphere as a algae bloom would cripple the biospheres ecosystem early on. As of week 6 every organism we introduced to our biosphere is still alive.

• What was your rational (i.e. more heterotrophs, equal heterotrophs to autotrophs, etc. and why)

As aforementioned, we wanted a balanced ecosystem, we added heterotrophs in the form of small snails, a larger snail, and one shrimp. In reality we probably added more autotrophs to the biosphere than heterotrophs, we can’t quantify the amount of photosynthetic microbes in the biosphere, but they most likely outnumber the amount of heterotrophs, we had three plants with soil bound root systems, and 1-2 free floating plants.

• What is the function/role or each of your organisms in your biosphere? What did you see them do?

The autotroph organisms are mostly photosynthetic so they provide oxygen to the heterotrophic organisms and heterotrophic ones provide CO2 to the photosynthetic ones so it's a win-win relationship.

• What changes did you observe in your biosphere over the last 6 weeks?  

There was progressively less leaves present on the plants as the weeks went on, this would be attributed to the heterotrophs eating the plants. The water also became more murky in the last couple other weeks, this would be due to photosynthetic algae becoming more prevalent in the ecosystem, this small algae bloom may get worse in the coming weeks and compromise the health of the biosphere, by making the environment more anaerobic.

• Were there any surprises?

For our biosphere, we were surprised that our shrimp and snails are doing very well considering at Week 1, our biosphere was extremely dark and murky which was also a surprise. When we first made our biosphere our group had issues from the very beginning, our biosphere did not look as if it was a stable environment to live in. We were concerned that the shrimp and snail would die early on in our research.

• Would you expect your biosphere to continue to function/survive? Why?

Yes,  because we added a lot of nutrients to the water. At this point in time, the only threats facing the functionality of the biosphere are algae bloom and running out of nutrients in the water.  

• Compare your biosphere to another group's biosphere? What are the similarities? What are the differences?  How do you account for the differences? I also did this lab in the other class too and everything was almost same as this one but because we forgot to add nutrients in water all of our animal dead the first week of the experiment and now the color of the jar is red and we don't know why.
• Reflection: What did the biosphere teach you about how ecosystems function? Ecosystems while they can take some amount of loss and still function properly are for the most part fragile constructs. Their whole existence is dependant on all organisms being kept in check, had the heterotroph populations boomed while the plant population stayed constant, the ecosystem would collapse, the same could be said for if the algae bloomed, the heterotrophs would be robbed of sufficient oxygen and the biosphere would have in turn collapsed. The biosphere walks a thin line between success and failure, had the ecosystem became largely unbalanced, it surely would have collapsed.
• Write at least 3 scientific questions based on your observations of your biosphere.

Was the nutrients amount was the only reason of our successful biosphere?

If we added daphnia would the biosphere be less murky?

How long could our Biosphere survive without outside input?

• Write 1 hypothesis based on the questions above.

Adding daphnia reduces the amount of algae present.

• Write an experiment your group could run to test the hypothesis above.

We could have two biospheres one with daphnia added, one without. We could add the same volume of photosynthetic microbes to each and equal amounts of nutrients while adding the same amount of plants and heterotrophs we used in our biosphere, over the span of 6 weeks we could see if Algae bloom is present in one, absent in the other, or present in both in varying levels.