In this activity, students sort samples into living or non-living things.
What makes something a living thing? To be called a living thing, an item must have once eaten, breathed and reproduced. A dead animal or plant is considered a living thing even though it is not alive.
Our coastal temperate rainforest is full of living and non-living things which interact to create a complete and stable ecosystem. When one tree dies and falls over, it becomes a home and provides nutrients for other living things. We call a fallen log with new plants growing on it a nurse log.
Living components of a forest include:
- plants (e.g. trees, ferns, mosses)
- animals (e.g. mammals, birds, insects, reptiles, amphibians)
- fungi
- bacteria
Nonliving things in a forest include:
- rocks
- water and rain
- sunlight
- air
The word ecosystem means ecological systems. Ecology is the study of ecosystems
An ecosystem includes all the living things (plants, animals and organisms) in a given area, interacting with each other, and with their non-living environments (weather, earth, sun, soil, climate, atmosphere). In an ecosystem, each organism has its own niche or role to play.
Ecosystems are the foundations of the Biosphere and they determine the health of the entire Earth system.
Sir Arthur George Tansley (1871 –1955) was an English botanist who introduced the concept of the ecosystem into biology
Ernst Heinrich Philipp August (1834 –1919) was a German biologist, naturalist philosopher, physician, professor, marine biologist, and artist who discovered, described and named thousands of new species mapped a genealogical tree relating all life forms invented many words commonly used by biologists today, such as phylum, phylogeny, and ecology.
An ecosystem is a community of living organisms (plants, animals and microbes) in a particular area.
The term `eco' refers to a part of the world and `system' refers to the co-ordinating units. An ecosystem is a community of organisms and their physical environment interacting together. Environment involves both living organisms and the non-living physical conditions. These two are inseparable but inter-related. The living and physical components are linked together through nutrient cycles and energy flows.
The organisms in an ecosystem are usually well balanced with each other and with their environment. An ecosystem may be natural or artificial, land-based or water-based. Artificial systems may include a cropland, a garden, a park or an aquarium. Introduction of new environmental factors or new species can have disastrous results, eventually leading to the collapse of an ecosystem and the death of many of its native species. Some of the major non-living factors of an ecosystem are: Sunlight Water Temperature Oxygen Soil Air
How big is an ecosystem?
Ecosystems can be of any size, but usually they are places. An ecosystem may be of very different size. It may be a whole forest, as well as a small pond. An ecosystem may be as large as the Great Barrier Reef or as small as the back of a spider crab's shell, which provides a home for plants and other animals, such as sponges, algae and worms.
Ecosystem boundaries are not marked (separated) by rigid lines. Ecosystems are often separated by geographical barriers such as deserts, mountains, oceans, lakes and rivers. As these borders are never rigid, ecosystems tend to blend into each other. Therefore, a lake can have many small ecosystems with their own unique characteristics. As a result, the whole earth can be seen as a single ecosystem, or a lake can be divided into several ecosystems, depending on the used scale. Scientists call this blending “ecotone”
Ecosystem diversity
Ecosystem diversity is the variety of ecosystems in a given place. An ecosystem is a community of organisms and their physical environment interacting together. For food, shelter, growth and development, all life systems interact with the environment. This is why it is necessary to preserve the ecosystems.
Scales of Ecosystems
Ecosystems come in indefinite sizes. It can exist in a small area such as underneath a rock, a decaying tree trunk, or a pond in your village, or it can exist in large forms such
as an entire rain forest. Technically, the Earth can be called a huge ecosystem.
Ecosystems can be classified into three main scales.
Micro: A small scale ecosystem such as a pond, puddle, tree trunk, under a rock etc.
Messo: A medium scale ecosystem such as a forest or a large lake.
Biome: A very large ecosystem or collection of ecosystems with similar biotic and abiotic factors such as an entire Rainforest with millions of animals and trees, with many different water bodies
running through them.
This focus idea is explored through:
Contrasting student and scientific views
Student everyday experience
Research: Hubber & Tytler (2004)
Their ideas of ecosystems are usually only associated with natural and wilderness areas rather than their own environments. This concept of an ecosystem also influences their ideas about how humans interact with ecosystems, which is often in terms of the destruction or collapse of natural and wilderness ecosystems rather than those systems that are part of their more immediate environments.
Research: Novak & Gowin (1984)
Scientific view
The world contains a wide diversity of physical conditions, which creates a variety of environments where living things can be found. In all these environments, organisms interact and use available resources, such as food, space, light, heat, water, air, and shelter. Each population of organisms, and the individuals within it, interact in specific ways that are limited by and can benefit from other organisms.
Interactions between different organisms are numerous and are usually described according to their positive (beneficial), negative or neutral effect on others.
The interactions between living things and their non living environment makes up a total ecosystem; understanding any one part of it requires knowledge of how that part interacts with the others.
Ecosystems do not ‘collapse’ but do change in function, structure and composition over time due to natural or human disturbance (examples include the impact of drought, flooding, mowing and herbicides).
Research: Novak and Gowin (1984)
Critical teaching ideas
- All organisms exist within ecosystems.
- Living things have various structures that enable them to survive: for example, transport structures in plants allow water and trace elements to move. Similarly there are digestive structures and respiratory structures in animals and reproductive structures in plants and animals that assist in organisms functioning within ecosystems.
- Each organism has particular forms of these structures that assist their survival.
- In all environments, organisms with similar needs may compete with one another for limited resources, including food, space, water, air and shelter.
Students need to experience evidence of a functioning ecosystem with abundant plant-animal interaction to develop a better understanding of the complexity of interactions and to understand that they themselves live within ecosystems.
Time is a factor that influences the type of interactions and changes that take place in an ecosystem. This is problematic for science planning that does not allow students to observe changes over an extended period of time. Allowing ongoing investigations to run throughout the year is an important consideration (or alternatively use video clips that record changes over time).
Research: Skamp (2004)
Teaching activities
Collect evidence/data for analysis
Identify a project within your local community where student research and involvement may have an impact.
Some examples are:
- Whale Dept. of Environment and Water Resources - Coasts and oceans
- Marine Coastal Projects
- Adopt a Dolphin - Whale and Dolphin Conservation Society
-
Dolphin Research Institute
Research: Baker (2005)
Challenge some existing ideas
In order to challenge the ideas that ecosystems only exist in wilderness areas and that human impact is always negative, encourage students to undertake activities which allow them to investigate living things in a natural local environment such as the schoolyard, local pond, a wetland or a constructed environment such as a classroom pond.
Research: Skamp (2004)
Collect evidence/data for analysis
Studying pond animals over a period of weeks gives a sense of the changes that occur in populations as they interact or in changes of form as animals go through their lifecycles. Students can link this with a longer study to provide insights to seasonal changes and animal adaptations related to seasonal cycles. The ten part TV series The Life of Birds completed by Sir David Attenborough in 1998 provides some great examples of how birds have adapted to urban environments.
Research: Skamp (2004)
Focus student attention on overlooked detail
Clarify and consolidate ideas for/by communication to others
Students could create a news report on their project or develop a project like creating a new playground. They could explore an issue for the media or their school newsletter from differing perspectives such as a politician, a greenie, a farmer, a parent, a local elder or other teachers. This involves ethical decision-making on behalf of the students as to what to include and what not to include in the report.
Further resources
Science related interactive learning objects can be found on the FUSE Teacher Resources page.
To access the interactive learning object below, teachers must login to FUSE and search by Learning Resource ID:
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Environmental evaluation project: frog pond habitat –students answer a short quiz about how organisms are adapted to their environment, then explore a pond environment. They choose sampling tools suited to avoid hurting the animals or damaging the study area, then collect animals from a pond, grassy bank, rocky bank, trees and shrubs. They look at a species description and video for each animal and
describe how the animal meets its basic needs for food, water, shelter and protection.
Learning Resource ID: R9QN9M
- Environmental evaluation project: frog pond habitat (2) – students explore why a frog population is declining by look at changes in the pond over time (specifically, water quality, habitat loss and predation by introduced species). Students build a food web
for the pond and model population interactions. They identify which species have the greatest impact on the frog and finally build a report using evidence collected to support their conclusions.
Learning Resource ID: FTE6CS