Ecology

Autotrophs use mineral elements and create their own organic material. Heterotrophs eat other living organisms to fulfill their needs in carbon compounds.

Autotrophs use carbon dioxide and water to build new carbon compounds. This process requires energy as these reactions arern‘t spontaneous. Light provides this amount of energy for photoautotrophs (e.g. plants using photosynthesis). They are called “producers”. Heterotrophs need organic food to function:

1. Consumers eat material from another living organism (e.g. Humans)
2. Saprotrophs eat material from dead organisms via external digestion (e.g. some bacteria or fungi)
3. Detritivores eat dead material via internal digestion (e.g. worm)

An ecosystem consists of different living organisms (biocenosis) interacting together and with their abiotic environment (biotope).

In an ecosystem, individuals from one species can eat other organisms and also be eaten by a third party. Those nutritive relationships build food chains.
Carbon enters the biosphere through the producers’ action. Those producers (plants) are eaten by primary consumers (rabbits), themselves eaten by foxes (secondary consumers), etc.
Each level of feeding in the chain is a loss of energy as all of the eaten‘s organism energy is not transferred in the eater‘s organism. This can be pictured in energy pyramids.
In the end, all of those organisms (producers and consumers) feed saprotrophs. Detritivores release carbon dioxide into the biotope and close the carbon cycle.

Humans have a major role on ecosystems balance and evolution.  Nowadays global warming is the most important human fight for the planet.

Human activities such as fishing, farming, but also industrialization, have an impact on ecosystems. It can unbalance the natural cycle by getting rid of some species (overfishing, intensive agriculture) or simply destroying a whole ecosystem (deforestation). Other human actions tend to prevent negative consequences and keep ecosystems and biodiversity protected.
Together, humans are a massive threat to ecosystems. Global warming is a major issue for human kind and the whole planet…