12 Year Old Terrarium - Life Inside a closed jar, Over a decade in isolation

In this video we take a look at the terrarium my brother made during his childhood. This terrarium was made between 2007 - 2008. This makes the terrarium at least 12 years old.

Inside there is a variety of organisms. All of which have persisted within the closed ecosystem for generations. Originally this terrarium was home to a lot more plant and isopod species, however as the years went by biodiversity was lost as the new ecosystem balanced out.

Currently the ecosystem is experiencing cycles. As the plant population increased, so did the isopods. This caused the isopod population to graze on a lot of the terrariums plants, causing the plant population to decrease. I imagine centipede populations may increase in future giving the plants the opportunity to recover.

I found this terrarium very fascinating as it's almost as if there are two separate worlds within the same glass demijohn. The algae underground creates a unique habitat, which couldn't possibly exist in nature due to the fact the glass ensured that light could reach the soil underground. This allowed algaes, moss and fungi to flourish, alongside any of the smaller invertebrates that lived among them.

Adult isopods seem to inhabit the surface and rarely venture below ground. I believe this is due to the hardness of the clay and rock substrate. The babies do seem to venture underground though, likely using tunnels left behind by earthworms many years ago.