C - Sustainability & Practical #5
Sustainability refers to the idea that something can continue indefinitely. Nowadays, sustainability is frequently discussed as human use of many resources (particularly fossil fuels) are unsustainable in the long term. Since the amount of fossil fuel is finite, current practices can not be continued indefinitely.
This concept can be seen in natural systems and can be used to guide the actions of future generations. In order to be sustainable, an ecosystem requires:
In a natural ecosystem, nutrients are recycled between organisms and so there is no shortage of the chemical elements necessary for life. Some excreted nutrients might be toxic, but they are typically broken down by microbes in the soil and then used by plants. However, energy cannot be recycled and so there must be a continued input. In most terrestrial systems, this energy is provided but the sun while in other types, it can come from heat.
Practical #5 - Sealed Mesocosm
Mesocosms are small systems that are used as ecological experiments. They can be fenced off areas within an ecosystem, an aquatic tank indoors or even plastic/glass bottles that you can set up yourself (see left diagram). These systems can be used to determine the effects of a variable on on the mesocosm as a whole (temperature, presence/absence of species.
Mesocosms can also be utilized to determine the sustainability of an ecosystem. To do this, a community of organisms and air/soil/water can be enclosed in a container. See the video below for an example.