Changes in the Environment

Environmental Change

Environmental changes affect the distribution of species in an ecosystem. These changes include:

  • Temperature - species will only be able to cope within a certain temperature range
  • Availability of Water - plants and animals must have sufficient levels of water in order to survive
  • Composition of Atmospheric Gases - plants and animals require specific gases in order to function
  • Seasonal - some species may not survive during specific seasons due to the change in the temperature and the food available
  • Human Interaction - certain species are hunted by humans


Biodiversity is the variety of all the different species of organisms on earth, or within an ecosystem.

A great biodiversity ensures the stability of ecosystems by reducing the dependence of one species on another for food, shelter and the maintenance of the physical environment.

Waste Management

Rapid growth in the human population and an increase in the standard of living means that increasingly more resources are used and more waste is produced. Unless waste and chemical materials are properly handled, more pollution will be caused.

Pollution can occur:

  • In water, from sewage, fertiliser or toxic chemicals.
  • In air, from smoke and acidic gases.
  • On land, from land ll and from toxic chemicals.

Pollution kills plants and animals which can reduce biodiversity.

Land Use

Humans reduce the amount of land available for other animals and plants by building, quarrying, farming and dumping waste. The destruction of peat bogs, and other areas of peat to produce garden compost, reduces the area of this habitat and thus the variety of different plant, animal and microorganism species that live there (biodiversity). The decay or burning of the peat releases carbon dioxide into the atmosphere.


Deforestation is when forests are taken down so that the land is used for something else (other than growing trees).

Large-scale deforestation in tropical areas has occurred to:

  • Provide land for cattle and rice fields
  • Grow crops for biofuels

However, this reduces biodiversity as lots of plants and animals survive in the forests as they become extinct. It also removes the potential of medication to be obtained, as lots of medicines are found in a range of plants. It also ruins the habitats in which animals would normally survive in. It also deeply affects the soil in the area. Deforestation also leads to an increase in carbon dioxide levels, which then leads to global warming.

Global Warming

Human activity is speed up the rate of global warming. The temperature of our earth is changing rapidly in the recent few decades due to the increase in carbon dioxide and methane levels in our atmosphere.

As humans burn more fossil fuels, more carbon dioxide is released into the atmosphere. As we chop down more trees during deforestation to use the land for our own good, it increases the amount of carbon dioxide in the atmosphere as there are less trees to photosynthesize.

Gases such as carbon dioxide form a layer around the Earth’s atmosphere. This layer normally allows heat from the sun to enter, and it stays within the atmosphere. We need the sunlight in order to survive as heat is extremely important for survival. However, the temperature is rising more and more as the layer around the Earth is getting thicker, meaning that more heat is being trapped.

Maintaining Biodiversity

The way that humans interact within the ecosystem can have both a positive and negative impact on biodiversity. Biodiversity is when there is a variety of living organisms living in a specific habitat.

Positive Impact

Negative Impact

  • Conservation - trying to keep hold of all the natural resources that we have on the planet before it becomes extinct.
  • Use of fertilisers to grow more products for human consumption
  • Introduce non-indigenous species to kill off pests, so that more products can be be produced without being ruined.
  • breeding programmes for endangered species
  • protection and regeneration of rare habitats
  • reintroduction of field margins and hedgerows in agricultural areas where farmers grow only one type of crop
  • reduction of deforestation and carbon dioxide emissions by some governments
  • Encouraging the recycling of resources rather than dumping waste in land falls
  • Overuse of fertilisers - fertilisers include nitrates, and it may run from fields into the river when it rains. This causes algae to grow, and it blocks out light from the plants that want to photosynthesize. Bacteria will now break down the plants and use up the oxygen which animals will need in the water.
  • Fish farming - farming fish in a large area within the lake or sea is an issue as farmers will empty chemicals, waste, pathogens, and parasites into surrounding water. This reduces biodiversity as it harms other animals living nearby. Some fish will be fed on other wild fish, and the population of the wild fish will decrease. Some fish may escape and compete with the original fish that are found in the area. They will end up competing for the same food and habitat, therefore there will be less biodiversity. Some other fish may get trapped in the nets, and will die as a result of that.
  • New indigenous species that are introduced to kill pests may out-compete the natural species.
What is global warming?
Your answer should include: Temperature / Earth / Changing / Rapidly / Recent / Decades
Explanation: The temperature of our earth is changing rapidly in the recent few decades due to the increase in carbon dioxide and methane levels in our atmosphere.
What is biodiversity?
Your answer should include: Variety / All / Different / Species / Organisms / Earth / Ecosystem
Explanation: Biodiversity is the variety of all the different species of organisms on earth, or within an ecosystem.
What is the advantage of introducing non-indigenous species?
Your answer should include: Kill / Pests / More / Products / Produced / Ruined
Explanation: It can kill off pests so that more products can be produced without being ruined.