ECOSYSTEM AND THE BIOSPHERE: Metaphors for Human-Induced Material Flows by Rudolph B. Husar ECOSYSTEM AND THE BIOSPHERE: Metaphors for Human-Induced Material Flows by Rudolph B. Husar Summary Report by Sarah Lahr ME 449 Sustainable Air Quality 2/4/02

Introduction n Natural ecosystems are made up of producers, consumers, and decomposers n Humans are responsible for extensive redistribution of chemicals on earth causing antropogenic stress on the earth’s natural system n How can the natural ecosystem be related to man- induced material flows?

Comparison of Ecosystem to Man-Induced System

How anthroposystems are different from ecosystems n Physical displacement between producer and consumer causing additional energy to be used (ex. oil products that are shipped all over the world) n No recycling after producers--it would be pointless to produce materials and recycle them immediately without going through a consumer. n Since little or no material is passed directly from the producer to the decomposer, the material goes out into the material environment, creating an open system.

Environmental Spheres The ecosystem analogy works as a simple way to compare the natural environment to the man-induced environment. This analogy does not take into account the physical transfer of material that occurs (i.e. oil being distributed all over the world.) The transfer of materials is understood using four environmental spheres The atmosphere is a transport-conveyor compartment that moves materials from atmospheric sources to receptors. This sphere has minimal storage capacity but a great capability for redistributing matter The hydrosphere acts as both a collector and a conveyer. The river system collects substances and delivers it to oceans. The lithosphere, the solid layer of inorganic matter on the surface of the earth, acts as a storage compartment for deposited matter. The biosphere, the thin layer of organic matter on the surface of the earth, acts as the heart of the system, causing matter to flow through all the spheres. This can cause continental and global-scale distribution of materials through the atmosphere. In this sphere, much matter and energy is also recycled. Human activity can be related to the biosphere because of its redistribution of material.

Conclusions n Both the ecosystem and the anthroposystem are a conceptual flow chart consisting of producers, consumers, and decomposers. n This flow chart allows for the framework of an ecomomic model to be created. n The main difference lies in the anthroposystem to recycle material, which in turn makes it an open system. n Closing the system brings in the four environmental spheres (atmosphere, hydrosphere, lithosphere, and biosphere) and allows for a flow of materials between all the spheres. n Human activities most closely resemble those of the biosphere.

Things I Learned I learned about the relationship between the natural system of the earth and that system which humans have created. It is interesting that a parallel can be drawn between the two concepts. The environmental spheres also made me think about how everything is connected and relates to everything else. It is easy in our society to think that material just “goes away”, but this model made me think about where everything goes and how it gets there.