Biosphere

The biosphere covers all living organisms from bacteria to whales, moss to trees and covers all ecosystems.

As the biosphere incorporates all living organisms of varying size, it is easiest to look at how organisms of a certain area interact with each other and their surroundings, than looking at each individual organism. Therefore we look often look at an ecosystem when studying the biosphere as this gives the best interpretation of the organisms and is essentially the biosphere, yet with the addition of the other spheres. http://www.eoearth.org/view/article/150667/ Retrieved 20/9/2015

Figure: Different ecosystems

An ecosystem is a biological community that is situated in a certain area e.g. forests, coastal shoreline, ocean, etc. This leaves lots of variables that can affect an ecosystem such as; environment, climate, size of the community, location (terrestrial or marine).

http://www.globalchange.umich.edu/globalchange1/current/lectures/kling/ecosystem/ecosystem.html Retrieved 20/9/2015

Figure 8 Four different ecosystems

Because of this there are many different ecosystems of varying size and biological make up, this helps to make the biosphere very diverse, in terms of what it consists of and how it interacts with the earth in comparison with the other spheres.

The biosphere is the primary biological moderator of Hydrogen, Oxygen, Carbon, Nitrogen, Phosphorus and Sulfur elements (SPONCH) and their associated cycles of change. The SPONCH element s are all vital elements in organisms.

How does the biosphere relate to the SPONCH cycles?

Sulfur: A key element in biochemical processes, energy and enzyme functioning. Throughout the cycle, sulphur is transferred amongst various states of ions and ionic compounds, this allows it to be used in a multitude of ways due to its valance electrons and can be oxidised/reduced readily. 

http://history.nasa.gov/CP-2156/ch1.3.htm 20/9/2015

Phosphorous: Key element in energy production of humans (ATP) and fertiliser.

Oxygen: Essential element for respiration and oxidation within chemical reactions.

Nitrogen: Makes up amino acids and enzymes both important biochemical stimulants for life. insert nitrogen cycle image

Carbon: Makes up all organic life due to its unique bonding capabilities. Insert carbon cycle image

Hydrogen: Essential element in chemical reactions and organic molecules, allowing the

formation of organic compounds.

We know that the biosphere helps to regulate the cycles of these essential elements, however what effects does society have on them? The two predominantly affected cycles are the nitrogen and phosphorous which isn’t surprising as both of them are key components of fertilisers.

Phosphorous: naturally occurs from the weathering of apatite by bicarbonate:

Ca₅(PO₄)₃OH + 4H₂CO₃ → 5Ca²⁺ + 3HPO₄^2- + 4HCO₃^- + H₂O

This is an incredibly slow process due to a low reactivity and the reactant form being slightly more stable than the product. So the natural formation of phosphorous is to slow to keep up with demand and as the world’s population increases and so too does the demand for food.  

This creates a major issue, as phosphorous is essential for not only agriculture, but for life as well.

Nitrogen: the Haber-Bosch process increased the ability to produce nitrate for fertilisers (nitrification) however the reverse process (denitrification) has not been formulated therefore a surplus of nitrate is being formed and is being very slowly turned back to nitrogen.

The reason nitrate is an issue is it is easily leached into water supplies making them unfit for human consumption.

So as humans we need to understand that the biosphere benefits us greatly yet we must look after it in return, for both the sustainability of the biosphere and society.