Ecosystems are delicately balanced natural systems. When the interaction between biotic and abiotic components is stable and harmonious, the ecosystem functions properly.
Let’s look at what can happen when a stable ecosystem is changed by removing or altering components.
Deciduous woodlands in the UK are examples of small-scale ecosystems, which we’ll use in the diagram below.
The deciduous woodlands ecosystem has been perfected over thousands of years but can be disrupted by natural events or human activities.
Natural events can include:
Human activities can include:
These actions can have immediate or dramatic effects on an ecosystem, while some are more gradual and subtle. By following the food web, we can see that hunting foxes would have a subtle effect in increasing the rabbit population. However, mass deforestation could affect the populations of all fauna in the woodlands.
In the case of deforestation, we can observe a ripple effect. ‘Ripple’ refers to the ripples that occur when an object is dropped in a body of water, and we see the ripples spread out from the point where the object was dropped. The ripples spread out, affecting the water around them, which is very much what happens in an ecosystem.
If the woodlands are deforested, having many trees cut down by human logging, then the following will happen:
1. The insects that rely on the tree, such as the butterfly, caterpillar and aphid, would lose their main form of energy consumption. As a result, large sections of the population would die out, or move to another woodland.
2. The beetle population, which relies on consuming aphids, would struggle for food. Therefore, many would die out or move to another woodland.
3. The robin, which relies on beetles, butterflies and caterpillars, would have a huge disruption to their food chain. Robins would struggle to eat enough, leaving many to die or to leave.
4. Due to the reduction in the population of robins, the sparrow hawk loses part of its diet. The number of sparrow hawks is reduced by starvation or relocation to another ecosystem.
The ripples affect almost all animals in the food web and the effects can be devastating for the once stable ecosystem.
|Stable||A condition where the ecosystem maintains its structure and function over time, without significant disturbance or loss of biodiversity|
|Biotic||Living components of an ecosystem|
|Abiotic||Non-Living components of an ecosystem|
|Deciduous Woodland||A type of ecosystem or biome that contains trees with broad leaves that shed their leaves annually, usually found in temperate regions with distinct seasonal variations|
|Natural Events||Events or phenomena that occur in nature without human intervention|
|Human Activities||Actions undertaken by humans that can impact the environment, including both constructive activities and those that may cause harm to ecosystems|
|Fauna||The animal life in a particular region, habitat or time period|