Closed Ecosystem & Resource Cycling

This project explored resource cycling within a closed ecosystem and examined how differences in external energy input could affect the stability of that system.

Because matter within a closed ecosystem must continuously cycle, the project focused on the relationships between producers, consumers, decomposers, water, nutrients, and external light energy.

Two closed terrariums were constructed with similar internal components and maintained as separate experimental systems.

The primary difference between them was the amount of light supplied. By changing energy input while attempting to keep other conditions comparable, the experiment aimed to observe how the systems responded over time.

Rather than observing only short-term changes, both terrariums were monitored for eleven weeks.

Changes in the terrariums were observed through factors such as plant condition, moisture, decomposition, and the overall state of the ecosystem.

The experiment treated these observations as interconnected rather than independent. Changes in light could affect photosynthesis, which could influence other parts of the system and alter the conditions experienced by organisms inside it.

The two terrariums developed differently over the eleven-week observation period, but the results could not be explained by differences in light alone.

Conditions within a small closed ecosystem proved difficult to control precisely. Moisture, soil conditions, decomposition, and differences in the construction of each terrarium could all affect the outcome.

This made it difficult to isolate energy input as the single cause of the observed differences.

Several possible sources of error became apparent during analysis, including differences in airtightness, excessive moisture, soil conditions, and insufficient control over microorganisms and other biological variables.

Because the systems contained many interacting components, even a small difference at the beginning of the experiment could develop into a larger difference over time.

A stronger follow-up experiment would require more standardized materials, tighter environmental control, and repeated trials.

I began the experiment expecting the effect of energy input to become relatively clear. Instead, the project demonstrated how difficult it is to isolate one variable inside a biological system.

The unexpected result shifted my attention from simply asking whether the hypothesis was correct to asking whether the experiment itself was capable of testing the hypothesis reliably.

That became one of the most valuable outcomes of the project: understanding that analyzing experimental limitations is not separate from research, but part of the research itself.