A bioactive terrarium is a terrarium in which plants, animals, fungi, and other micro-organisms work together in complex and fascinating ways just like in an ecosystem in the natural world.
What is a Bioactive Terrarium?
A bioactive terrarium goes further than many terraria that just grow plants. The idea is that the terrarium moves beyond just being a plant display and becomes far more like a ‘real world’ living ecosystem.
In a bioactive terrarium, living plants and terrestrial animal species co-exist within the enclosure, alongside detritivores, or waste-eaters, that naturally ‘clean up’ and recycle waste within the system.
Why Create a Bioactive Terrarium?
Adopting a bioactive approach in a terrarium cuts down on the maintenance we humans have to do and helps us to move much closer to a self-sustaining system. Long-term sustainability is the goal.
Often, when growing plants indoors, we can reduce maintenance needs by working more closely with nature. By mimicking as closely as possible the form and function of a natural ecosystem, we can lower maintenance systems within our homes.
A bioactive terrarium incorporates more than just plants. This means greater diversity within the system.
Greater biodiversity within a system means more beneficial links between species, and more beneficial interaction means greater stability and resilience. This means that a bioactive terrarium is far more likely to endure and stand the test of time.
The Basics of a Bioactive Setup
Bioactivity is something we can aim for in plant terraria and in terraria or vivaria designed to house terrestrial animal species. In either case, the goal is to consider the additions we might make to enable natural function to take over and a more or less closed-loop system to form.
A bioactive setup usually involves closed terrariums – those used to grow high-humidity plants typically from tropical climes. But in theory, any open or closed terrarium can potentially become a proper ecosystem with a bioactive setup.
For a bioactive terrarium, you need:
- A suitable substrate (soil, mulch, etc…) in which plants can grow and organisms can live and feed.
- Bioactive terrarium detritivore species. These creatures are the ‘clean up crew’ – the recyclers who play crucial roles in maintaining cyclical systems.
The Substrate in a Bioactive Terrarium
A lot of crucial function in a bioactive terrarium comes back to the substrate, which is like the ever-precious soil in a natural ecosystem.
Whenever we grow plants we neglect the soil or growing medium at our peril. And in a bioactive terrarium, the substrate may differ from natural soil, but it serves many of the same functions.
The substrate in any terrarium serves as the growing location for your plants. Many plants uptake water and nutrients from this material, in which their roots grow. It is important to choose the right substrate for the specific plants that you wish to grow.
In a bioactive terrarium, the substrate also has to shelter and feed the organisms that you enlist to help you as your clean-up crew for the system. So you need to choose the ingredients for this substrate carefully to keep them as well as your plants happy.
In a closed terrarium, the ingredients for the substrate may differ somewhat from case to case, and there may be different needs for an open terrarium. But there are certain ingredients commonly used in terrarium soil that will be used in many bioactive terrarium setups.
A bioactive substrate mix will often combine ingredients such as:
- orchid bark
- tree-fern fiber
- coco-fibre/ coir
- leaf mold/ leaf litter
- activated charcoal
Though there are numerous options and specific mixes that will suit different plants and situations.
As a general rule, a high organic matter content will be crucial for long-term sustainability in a bioactive terrarium. It will feed the creatures upon which the system depends.
But it is important not to include material likely to bring unwanted bacteria (or other unwanted micro-organisms) into the bioactive terrarium system.
Choosing Detritivores for a Bioactive Terrarium
Detritivores are microfauna that break down the organic material within the system and convert it into nutrients that can be taken up by the terrarium plants. Choosing the right creatures for your needs is one of the most important elements in the design of a bioactive terrarium.
Some common creatures used within a bioactive terrarium include:
- Isopods (Pill Bugs)
- Worms – Earthworms or Mealworms
Springtails are among the most popular options. They are famed for their ability to eat mold, cheap, readily available, and small enough for a terrarium of any size.
Pill bugs can work synergistically with these creatures. They are also a popular choice and come in many sizes, often with a very striking and different appearance in terms of color and design.
Several different species of worms can also work well within a bioactive terrarium substrate. They not only break down organic material and add worm castings for the mix but also aerate the medium as they make their tunnels through it.
Earthworms can often be used and mealworms are another option that can work in drier, open terraria as well as closed terrarium systems.
Millipedes are another potential detritivore to add to a system, while centipedes are predators that can help keep the ecosystem in balance by keeping down the numbers of other creatures within the system.
Within the substrate, and potentially on decomposing wood or other natural features within your terrarium, fungi, and other micro-organisms will also be present, playing their own roles within the bioactive terrarium system in addition to the above.
These are not the only options, of course, but are among the best options to consider for a bioactive terrarium.