Ecosystem Structure
This section explores the fundamental building blocks of any ecosystem, from its living and non-living parts to how life is organized into different levels. Understanding this structure is key to seeing how everything in nature is connected.
Parts of an Ecosystem
An ecosystem is a community of interacting organisms and their physical environment.
Biotic Components (Living)
Producers (plants), Consumers (animals), Decomposers (fungi, bacteria).
Abiotic Components (Non-living)
Water, air, soil, rocks, temperature, and sunlight.
Biodiversity & Stability
Biodiversity refers to the variety of life. More variety means a stronger, more stable ecosystem.
High Biodiversity
An ecosystem with many different species (like a rainforest) is more stable and can better withstand changes.
Low Biodiversity
An ecosystem with few species (like a farm field) is less stable and vulnerable to collapse from disease or environmental change.
Levels of Organization
Organism
A single, individual living thing (e.g., one hawk).
Population
All members of the same species in an area (e.g., all hawks in a forest).
Community
All the different populations living together (e.g., hawks, trees, mice).
Ecosystem
The community plus all abiotic factors (living things + air, water, soil).
Biosphere
The sum of all ecosystems; the part of Earth where life exists.
Energy Flow & Chemical Reactions
This section covers how energy moves through an ecosystem and the crucial chemical reactions that make life possible. Explore the difference between how plants make food and how all living things use it, and see how energy is transferred from one organism to another.
Photosynthesis vs. Cellular Respiration
Energy Flow & The 10% Rule
Energy flows in one direction, from the sun to producers, then to consumers. With each step, about 90% of the energy is lost as heat.
Cycling of Matter
Unlike energy which flows in one direction, matter (like water and carbon) is recycled over and over. This section provides interactive diagrams to help you visualize how these essential materials move through the living and non-living parts of our planet.
The Water Cycle
The Carbon Cycle
Patterns of Interactions Among Organisms
No organism lives in isolation. This section explores the five main ways that species interact with each other in a community. Click on each card to learn about the relationship, see an example, and understand who benefits and who is harmed.
Ecosystem Changes & Populations
Ecosystems are dynamic and constantly changing. Here, you'll learn how physical and biological changes can affect the size of populations, and how scientists use data to form arguments about these effects. Interact with the chart to see how resource availability can be a limiting factor.
Limiting Factors
Changes can act as limiting factors that control population size. A drought (physical change) or a new disease (biological change) can cause a population to shrink.
Analyzing Data: Rainfall & Population
Scientists analyze data to find patterns. This chart shows a relationship between rainfall and a hypothetical gazelle population over several years. Click the labels below to see how an argument is constructed.
Claim: Gazelle populations are directly affected by rainfall.
Evidence: In years with high rainfall (e.g., Year 3, 5), the population peaks. In years with low rainfall (Year 2, 4), it drops.
Reasoning: Rainfall (a physical component) leads to more grass (food resource), which supports a larger gazelle population.
Biodiversity Conservation
Biodiversity is essential for healthy ecosystems, but it is under threat. In this final section, you will learn how scientists measure the variety of life and explore the different methods we can use to protect and maintain it for the future.
Measuring Biodiversity
- Species Richness: The simplest method - counting the total number of different species in an area.
- Species Evenness: Comparing the population sizes of each different species. High evenness is better.
- Sampling: Using tools like quadrats (square frames) to count species in small areas to estimate the total for a larger region.
Maintaining Biodiversity
- Habitat Preservation: Creating National Parks and protected areas to save ecosystems.
- Sustainable Use: Setting responsible limits on fishing, logging, and hunting.
- Controlling Pollution: Reducing harmful chemicals in air and water.
- Ex-Situ Conservation: Protecting species outside their natural habitat, like in zoos or seed banks.