Unavoidable Extinctions in Ecosystems of Extreme Isolation.

Area of Science:

• Ecology
• Biodiversity Studies
• Space Exploration

Background:

• Future space exploration and isolated habitats may necessitate self-sustaining onboard ecosystems.
• Biosphere 2 was an experimental closed ecological system designed to mimic Earth's biosphere.
• Assessing species survival within such enclosed environments is crucial for long-term viability.

Purpose of the Study:

• To analyze plant species survival data from Biosphere 2's first mission using the neutral theory of biodiversity (NTB).
• To gain new insights into the dynamics of closed ecological communities and species loss.
• To evaluate the adequacy of experimental durations for simulated ecosystems.

Main Methods:

• Applied the neutral theory of biodiversity (NTB) framework to plant species survival data from Biosphere 2's tropical rainforest sector.
• Compared observed species loss rates with predictions generated by NTB for closed communities.
• Analyzed the temporal requirements for validating NTB predictions in experimental ecosystems.

Main Results:

• Biosphere 2 experienced species loss at a rate exceeding neutral theory predictions.
• NTB indicates that species loss is an inherent characteristic of closed ecological communities within a specific timeframe.
• The study suggests Biosphere 2's operational duration was insufficient by a factor of at least 30 to properly test NTB.

Conclusions:

• The neutral theory of biodiversity offers valuable perspectives on Biosphere 2's species dynamics.
• Extended operational and testing durations are essential for future microcosm and simulated ecosystem studies.
• Findings have implications for designing and evaluating closed ecological systems for space habitation and other applications.