“Could I do better at the place where a billion-dollar project has failed?”
The question constantly bugged me last winter. In the biology class, we had just finished the ecosystem part. Not satisfied with the somewhat pessimistic textbook conclusion, I decided to take the problem into my own hands: After getting advice from the teacher, I spent a large portion of my savings to order a glass tank, and started the half-a-year experiment on my own “biosphere.”
I divided my biosphere into two biomes. First was a “grassland” with cactus, loosestrife, plain lawn grass, moss, and a certain type of fern. I used sand as the bottom buffer layer, and piled some rich black soil above it for the plants. In addition to that, I created a little “lake” with waterweeds and decorated it with some pebbles. Animals that were on the roster included one spider, two tortoises, five shrimps, and ten earthworms. Realizing photosynthesis would be the key in my experiment, I put the tank on the balcony where light is always abundant. Then assuming too much sunshine would surely overheat water and atmosphere, I covered the lower half of the tank with cardboard and the upper half with semitransparent filter made of old newspaper. Just perfect.
I would spend ten minutes every day observing this miniature cosmos, and was disappointed to find out that there was nothing to see in winter. Tortoises and shrimps all spent their days in peace. Plants did not grow a single millimeter in three weeks. Earthworms? Never to be found again.
However, things became much different when the spring came. Tortoises performed their daily routine between water and the highland where they could take a sunbath. Shrimps moved to and fro, bringing much liveliness to the aquatic zone. Little (diameter<6mm) blue flowers flourished on the land. Although on average each only lasted no more than a few days, watching them gave me an inexplicable joy.
I was too happy to notice the omens, like when loosestrife began to outgrow others. Taking advantage of a complex root network and the high temperature in the tank, it soon dominated the limited space available. Blue flowers withered at first, and then it was the turn for fern and lawn grass. Eventually, only some yellowish, withering leaves and the lonely cactus took a last stand in the corner. For animals, at first all shrimps died out due to deteriorating water. The final straw was on June 3rd, an extremely harsh summer day when the smaller tortoise passed away. Watching its lifeless carcass silently floated on water, I decided it was the time to stop. I spent a whole day to place every animal and plant back in the free world they belong to, and set up a nice grave for Tutu the Tortoise. It was the least I could do for them.
The failure does not differ much from that of Biosphere 2. By the end of its first mission, 19 out of 25 vertebrate species went extinct, ocean and air were polluted, pollinating insects died out, and oxygen level dropped to as low as 14% before mission control decided to intervene. I learned that my system might last longer with improved ways of temperature control and increased biological diversity. Nevertheless, what first-hand experience really taught me was that our earth will be THE BIOSPHERE in the foreseeable future. We shall indeed do everything to understand it, cherish it, and guard it. Moreover, introduced species could either become victims of the alien environment, or endanger native species as dominant powers. The harmonious coexistence of flora and fauna should always be valued when attempting to preserve an ecosystem.