Studying sustainability in DP Biology

 

Kate Perry
Head of Science and Biology Teacher
 

DP Biologists are now studying what factors make ecosystems sustainable. To do this, we are using mesocosms. What’s a mesocosm? A mesocosm is a small model of an ecosystem that can be used for experiments: scientists worldwide use mesocosms to investigate global warming, ocean acidification and other factors that potentially threaten sustainability. Our mesocosms, though simpler, still investigate the sustainability of ecosystems. In accordance with the IB Ethical Experimentation policy, we are not including any animals in case the conditions inside cannot support such life. However, the mesocosm pictured below, with only plants and soil, has been closed and sealed for over two years, and the plant is thriving!

From the Biology perspective, sustainability in ecosystems depends on nutrient availability, energy availability, and removal or detoxification of waste products. We have designed our mesocosms to have sufficient nutrients from rich potting soil and plenty of water. The soil provides a healthy bacterial community to recycle nutrients and waste. We use local Jeju succulent plants that are adapted to the humid environment inside the mesocosm, and produce food through photosynthesis. Energy for photosynthesis is provided by sunlight as our mesocosms sit in the classroom window. One of our experiments investigates how the mass of soil used affects the sustainability of the ecosystem. We will observe the plant’s growth as evidence of sustainability. Check back in two years to see which mesocosms are still sustainable!