A biodome is an architectural structure designed to enclose and sustain a self-regulating ecosystem. These expansive, often transparent enclosures replicate the specific environmental conditions, or biomes, of a particular region, such as a rainforest or a desert. The primary purpose is to allow a diverse collection of plants and animals to thrive in a controlled environment, making them unique tools for both science and education. The structures are engineered to mimic the complex interactions found in nature.
Defining the Contained Ecosystem
A biodome maintains a delicate balance of atmospheric, hydrological, and biological processes within a sealed or semi-sealed environment. Unlike a typical greenhouse, which is primarily focused on climate control for horticulture, a biodome aims for ecological stability to support multiple trophic levels. This stability is achieved through engineering systems that manage the air quality, water cycling, and energy flow necessary for the ecosystem’s survival.
Atmospheric regulation is managed by maintaining specific humidity and gas concentrations, balancing the oxygen produced by plants during photosynthesis with the carbon dioxide released during respiration by all living organisms. The structure itself, often built with materials like ethylene tetrafluoroethylene (ETFE) or glass, is designed to maximize solar energy transmission, which plants use as their primary energy source. This solar energy drives the entire system.
Water cycling within the system mirrors Earth’s own hydrological cycle. Water evaporates from plants and surfaces, condenses on the cooler interior surfaces, and then returns to the soil as precipitation. This continuous recycling process sustains plant life and minimizes the need for external water input. The ecosystem must also contain all the necessary components for nutrient recycling, including decomposers like fungi and microbes in the soil to break down dead organic matter and return nutrients to the living plants.
Primary Functions and Research Applications
The construction of these complex enclosed ecosystems serves multiple purposes, ranging from preserving biodiversity to advancing space exploration research. One main function is conservation, where biodomes act as modern-day “arks” for endangered or rare plant species threatened by habitat loss or climate change in the wild. By providing an authentic and protected habitat, they allow scientists to study and propagate these species to ensure their long-term survival.
Biodomes also serve as platforms for scientific research, allowing researchers to study ecosystem dynamics in a controlled setting. Scientists can model the effects of environmental shifts, such as increased atmospheric carbon dioxide or changes in temperature, on entire biomes without the complexities of the open environment. This capability is particularly relevant for developing models of climate change and understanding how natural systems might adapt to future conditions.
A third major function is public outreach and education, offering visitors an immersive experience of diverse biomes. These facilities foster a deeper understanding of ecological interconnections and the importance of biodiversity. Furthermore, the contained nature of biodomes has made them valuable for exploring the feasibility of human habitation in closed systems, providing insights that are relevant for long-duration missions to the Moon or Mars.
Notable Biodomes Around the World
The ambition of biodome projects is illustrated by several large-scale facilities around the globe, each with a distinct focus. Biosphere 2, located in the Arizona desert, stands out as a sealed experiment originally designed to be a completely self-sufficient system for human occupants. The massive glass and steel structure, which encompasses a rainforest, ocean, savannah, and fog desert, was initially built to test the possibility of creating off-world habitats and to conduct large-scale ecological research.
In contrast, the Eden Project in Cornwall, UK, focuses on public education and conservation through its two enormous geodesic domes. The structures are built from inflatable plastic cells and house the world’s largest indoor rainforest and a Mediterranean biome, allowing millions of visitors to experience diverse plant life. The facility also demonstrates sustainable practices, using collected rainwater for its humid environment and generating a portion of its own power.
The Montreal Biodome in Canada, which was repurposed from the velodrome used in the 1976 Summer Olympics, houses five distinct ecosystems of the Americas under a single roof. Visitors can walk through a tropical rainforest, the Laurentian maple forest, and sub-polar regions, each faithfully recreated with indigenous flora and fauna. This facility emphasizes the interconnectedness of different geographical environments and is a major center for biodiversity education.