Ecology and conservation
Ecology is the study of the interactions between organisms and their environment.
An environment simply describes everything around an organism that affects its survival. Organisms need to interact with their environment to survive:
A horse eats grass in a field. The grass requires light, carbon dioxide and water to grow. The horse may provide the grass with carbon dioxide from respiration and nutrients from faeces.
Important! The environment is often assumed to be global. In ecology, every organism has a unique environment, though parts of its environment may be shared with other organisms.
Conservation aims to protect endangered species and their natural habitats.
Conservation is an important part of ecology. An estimated 10,000 species become extinct every year! Much of this loss is due to human activity.
Deforestation has wiped out thousands of insect species.
Conservation aims to make human activity sustainable. From an ecologist's perspective, this means that activity maintains biodiversity (variety of species) over time. Below are two examples of conservation in action:
- Managing timber production. Preventing illegal deforestation and replacing forests helps to maintain habitats.
- Managing fisheries. Reducing fishing of endangered species (e.g. sharks) can prevent extinction. Building sustainable fish farms reduces the reliance on wild fish stocks.
Logging in the Amazon rainforest has destroyed an area of 600,000 km$$^2$$ over the last 30 years.
Deforestation is the destruction or removal of large areas of woodland.
Humans have been cutting down trees for thousands of years and using the wood for timber. However, deforestation is increasingly used to provide more land for agriculture.
The effects of deforestation can be dramatic and long lasting:
- Increased carbon dioxide : Fewer trees mean less carbon dioxide is removed from the atmosphere by photosynthesis .
Carbon dioxide is released when trees are burnt , a common tactic in deforestation.
Decomposers break down dead plant material and respire, releasing carbon dioxide.
- Destruction of forest habitats : Forests are an important habitat supporting millions of species. Deforestation can lead to the extinction of species , reducing biodiversity.
- Soil erosion : Trees absorb a lot of water from the soil, and their roots help to stabilise the soil. When trees are removed, water accumulates in soil and can cause landslides .
Deforestation also reduces soil fertility as trees contain most of the nutrients in forest ecosystems.