Let's start with the big question, what is ecology?
To put the answer simply - Ecology is the study of the relationships between a species (plants/animals) and their environment (living organisms and their habitats). Every organism depends on living and non-living things to survive.
"The first law of ecology is that everything is related to everything else."
Ecology - Junior Cycle Science Learning Objectives
- To be able to define that living things are affected by the requirements and respond to changes thank her and said environment.
- To be able to define that the population of a species depend on the availability of food and the presence or absence of organisms in their environments.
- To provide a listed example of Producers, Consumers and Decomposers in an ecosystem.
- To identify a food chain and a food web from a named habitat and identified examples of adaption competition and interdependence.
- Study of a local habitat - by using appropriate instruments and simple keys you should be able to show the variety and distribution of named organisms, in your experiment log.
We won't be able to look at everything all heading above in detail, but we will manage to look at a few and hopefully provide you with some new study material that you may not already have.
Producers, Consumers and Decomposers in an Ecosystem
Producers - "green" plants are known as producers because they make their own food. (They get their energy from the sun.)
Consumers - All other organisms get their food by eating plants or animals. These are split into three main groups:
- Herbivores - eat plants only e.g. rabbits.
- Carnivores - eat meat only e.g. halks.
- Omnivores - eat both plants and meat e.g. Badgers.
Decomposers - the function of decomposers in an ecosystem is to break down dead material to recycle the nutrients. Fungi and bacteria do this.
"Fungi are the grand recyclers of the planet and the vanguard species in habitat restoration."
Let's look at this and a little more detail. A food chain is a chain showing how organisms are linked by what they eat. Solar energy is transferred through a food chain.
- Producers are organisms that make their own food, e.g. green plants. Plants make their own food using a process called photosynthesis. Green plants that photosynthesise are called producers. The chlorophyll in their leaves allows them to capture sunlight energy and convert it into food. Plants are important providers of food for animals. They can also provide other plants with shelter, support, food or protection.
- Consumers are all organisms other than producers (insects and animals that consume plants and each other to survive). Animals are consumers because they can't make their own food. They are classified according to what they eat. Many insects, birds, reptiles, fish and mammals are called carnivores because they eat meat.
- Decomposers are organisms that feed on dead animals or plants e.g. woodlice, fungi. Bacteria and fungi feed off dead, decaying, organic material and break it down into simple nutrients that are returned to the soil or water. These substances are then re-used by the producers.
The feeding level is the position of a particular organism in a food chain. Producers are at the first feeding level.
A food web is a number of intersected food chains. A food chain is a way energy is passed from one organism to the next.
An example of a food chain from a hedgerow habitat:
Let's call the Hawthorn hedge our producer > it is consumed by the Greenfly > which is consumed by the Spider > and finally consumed by the Blackbird
Habitats Notes - Ecology, Junior Cycle Science
A habitat is a place where an organism makes its home. A habitat meets all the environmental conditions an organism needs to survive. The main components in a good habitat are shelter, water, food, and space.
Below is an example of how smaller organisms interact in the Irish wildlife:
- Animals need plants for food and also for shelter. e.g. Birds build nests in trees.
- Plants rely on animals to move pollen and seeds. e.g. Bees carry pollen to other flowers.
- Bacteria and Fungi recycle decaying plants and animals
How Humans Negatively Affect Habitats Around Them
Human activity plays an important role in the health of ecosystems all around the world. Unfortunately, not all advancements by humans have positive effects on the natural world. In fact, humans have a rather large negative effect on the health of ecosystems. Just some of the negative effects we as humans have on natural habitat include:
Pollution - a lot of the pollution which we emit comes from fossil fuels (oil, petrol, diesel, coal, turf etc...) or Industry production can contaminate the food supply for a species, potentially changing an entire food web. On a personal level when we refuse to put our trash in the right place and litter or we excessively buy and throw away non-recyclable products constantly we are contributing to the amount of pollution globally. Even just upgrading your phone without correctly recycling it contributes to damaging the ecosystem.
Invasive species - Introducing a new species from another part of the world into an unfamiliar environment can have unintended and negative impacts on local lifeforms. Invasive species can be any form of living organism that is brought by humans to a new part of the world where they have no natural predators. (The addition or subtraction of a single species from an ecosystem can create a domino effect on many others, whether that be from the spread of disease or overhunting.)
Expansion - Our cities and towns are constantly getting bigger, which means we are regularly pushing out further and further into the countryside and which in turn is destroying a lot of natural habitats. This has a massive effect on feral animals, such as insects, birds, squirrels, foxes, rabbits and other wild animals.
Key Terms Relating to Ecology - Junior Cycle Science
While studying the topic of ecology, just like other topics which you will study in junior cycle science, such as the digestive system and human reproduction, there are certain terms that you really should make a note of. Just some of those terms include:
- Ecology is the study of plants and animals and their environment.
- Habitat is the area where a species (organism) lives.
- Adaptation is when an organism changes in order to be better suited to survive in its habitat.
- Interdependence is when organisms depend on each other for food or another resource. An example being how insects rely on plants for food and plants rely on insects for pollination.
- Competition is where organisms compete for a resource that is in short supply. An example is how plants in a forest compete for light and water.
- Invasive Species is any form of living organism that is brought by humans to a new part of the world where they have no natural predators.
- Pollution is the contamination of natural habitats due to excessive human waste and they use of fossil fuels.
If you want to try out some online activities to expand your Ecology knowledge, National Geographic has a wonderful task on Ecological Relationships which you can find here.
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