Question

While we have been fixated mostly on the biotic players, the abiotic parts of an ecosystem are critically important as well. Whether it is the hydrologic, carbon, nitrogen, or phosphorus cycle, they all need to function well to maintain the homeostasis of ecosystems. Explain how the carbon cycle in its natural state works and then explain how humans have disrupted/altered it.

Answer 1

Generally the carbon cycle is very important to the ecosystem and existence of all the organisms. During respiration, the animals and humans release carbon in the atmosphere and breathe in the oxygen that is released by the plants. The carbon dioxide is absorbed by the producers that make carbohydrates by photosynthesis and the animals feed along the carbon compounds along the food chain. The carbon consumed is exhaled as carbon dioxide and consumed by plants to make food.

We have disrupted the system by cutting down plants and with increased deforestation. The urbanization and industrialization has polluted the environment and disturbed the ecosystem that makes it difficult to breath fresh oxygen

There is constant movement of energy and matter through the ecosystems. The organisms that are found in the ecosystem have adaptations that arise from natural selection which help them get energy and matter from a particular eco-system. Both energy and matter are conserved which is neither destroyed nor created but it takes different routes through eco-system

·         Matter is recycled; the same atoms are reused over and over.

·         Energy flows through the ecosystem, usually entering as light and exiting as heat.

The matter is recycled through the Earth’s ecosystem and it may move from one ecosystem to another. The same molecules or atoms are used again and again which are assembled into different chemical forms and incorporated into the bodies of different organisms.

A land plant takes in carbon dioxide from the atmosphere and other nutrients, such as nitrogen and phosphorous, from the soil to build the molecules that make up its cells. When an animal eats the plant, it uses the plant’s molecules for energy and as building material for its own cells, often rearranging atoms and molecules into new forms.

When plants and animals carry out cellular respiration—break down molecules as fuel—carbon dioxide is released into the atmosphere. Similarly, when they excrete waste or die, their chemical compounds are used for energy and building material by bacteria and fungi. These decomposers release simple molecules back into the soil and atmosphere, where they can be taken up anew in the next round of the cycle.

The energy flow is always unidirectional throughout the eco-system and is generally received as light and exit as heat. The energy mostly enters the eco-system as sunlight which is captured in chemical form by photosynthetic plants and algae. The energy than pass through the eco-system changing forms as organisms metabolize, produce waste, eat one another and eventually die and decompose.

Each time energy changes forms, some of it is converted to heat. Heat is a form of energy and hence no energy is destroyed. The energy that entered the ecosystem as sunlight is dissipated as heat and radiated back into the space.