Contextualization

In Biology, one of the fundamental concepts for studying the relationship between organisms and ecosystems is to understand the food chain and food web. The food chain is a linear representation of the feeding relationships between organisms in an ecosystem, which always starts with producers, usually plants, that capture energy from the sun and continues with different levels of consumers, ending with decomposers. However, few ecosystems function in such a simplistic way. Many organisms have varied diets, leading us to the food web, a more complex and precise representation of how energy and nutrients move in the natural world.

The importance of understanding the food chain and food web is twofold. First, they help elucidate the complexity of ecological interactions, showing how each organism is connected to the world around it. Each organism has a role, whether it is a producer that captures energy, a consumer that feeds on other organisms, or a decomposer that helps recycle materials back into the ecosystem. Secondly, understanding the food chain and food web provides a basis for understanding how human actions can alter these interactions, with potentially serious consequences for the environment.

Preservation and conservation of biodiversity are intrinsically linked to the healthy maintenance of food chains and food webs. The loss of species at any level - producer, consumer, or decomposer - can have cascading consequences throughout the ecosystem. Furthermore, humanity has shaped ecosystems in direct and indirect ways, whether through hunting, agriculture, or through indirect effects such as climate change.

In this sense, this project aims to explore the concepts of food chain and food web and their implications for biodiversity preservation. To do this, students will explore an ecosystem, build a theoretical food web, and then investigate how the introduction or removal of species can affect the food web they have created. Finally, they will discuss how these changes relate to human actions, environmental policies, and the planet's sustainability.

Activity - "Building and Manipulating the Food Web"

Project Objectives:

1. Understand the concepts of food chain and food web
2. Differentiate between producers, consumers, and decomposers
3. Evaluate the impact of human actions on food webs
4. Develop teamwork and time management skills

Project Description:

In this project, you will choose a natural ecosystem and, from there, create a representation of its food web. Then, you will modify this food web by introducing or removing species to assess the impact of these changes. Finally, discussions will be held on how these changes in the food web relate to human actions and environmental policies.

Required Materials:

1. Books, websites, and other materials for research on ecosystems and food webs
2. Paper and colored markers (or graphic design software, if you prefer to create digitally)
3. Access to a computer and the internet for research and report preparation

Step by Step:

1. Research and ecosystem selection (approximately 2 hours):

Based on the chosen research materials, each team must select a natural ecosystem to be the focus of the project. You should delve into research on the species that inhabit this ecosystem, highlighting their roles within the food web (producers, consumers, and decomposers).

2. Creation of the food web (approximately 3 hours):

The team must then create a visual representation of the food web of this ecosystem. Keep in mind that producers are the base of the web, followed by consumers, and finally, decomposers. Use colors to distinguish between the different levels of the food web.

3. Manipulation of the food web (approximately 3 hours):

Now, think of a species that is important to the food web you have created. You will then create two new versions of this food web: one in which the chosen species has been removed and another in which the species has been added in excess. Discuss and note what the possible consequences of these changes to the ecosystem would be.

4. Relation to human action (approximately 2 hours):

Based on your changes to the food web, analyze how human actions can cause similar changes in real ecosystems. For example, the introduction of a non-native species can be compared to your addition of a species in excess.

Project Deliverables:

1. The created food webs (original, with species removed, and with species added in excess).

2. Written report:

Students must write a report on the project, following the structure: Introduction, Development, Conclusions, and Bibliography.

• In the introduction, contextualize the theme of the food web and the chosen ecosystem.
• In the development, explain the original food web, the changes made, and the theoretical consequences of these changes. Additionally, report the methodology used.
• In the conclusions, summarize what you have learned throughout the project and how it relates to human actions, environmental policies, and the sustainability of the planet.
• In the bibliography, list all sources used during the research.

Students should be able to discuss the importance of preserving and conserving biodiversity, considering qualitative and quantitative parameters, and evaluate the effects of human actions and environmental policies to ensure the sustainability of the planet.