Topic: Ecosystem –the flow of matterr and the flow of energy

Target group

8th‑grade students of elementary school

Core curriculum

General requirements

I. Knowledge of biological diversity and basic biological phenomena and processes. Student:

3. presents and explains the relationship between the organism and the environment.

Specific requirements

VII. Ecology and environmental protection. Student:

5. presents the trophic structure of the ecosystem, distinguishes producers, consumers (I and further orders) and destructors, and presents their role in the circulation of matter and energy flow through the ecosystem.

General aim of education

You will learn about the transformation of energy and matter in the ecosystem

Key competences

• communication in foreign languages;

• digital competence;

• learning to learn.

Criteria for success
The student will learn:

• to explain what the process of circulation of matter and energy in an ecosystem consists of;

• to explain why energy loss takes place while the matter is moving through the food system..

Methods/techniques

• expository

  • talk.

• activating

  • discussion;

  • brainstorming.

• exposing

  • exposition.

• programmed

  • with computer;

  • with e‑textbook.

• practical

  • exercices concerned.

Forms of work

• individual activity;

• activity in pairs;

• activity in groups;

• collective activity.

Teaching aids

• e‑textbook;

• notebook and crayons/felt‑tip pens;

• interactive whiteboard, tablets/computers.

Lesson plan overview

Before classes

• Students get acquainted with the content of the abstract. They prepare to work on the lesson in such a way to be able to summarize the material read in their own words and solve the tasks themselves.

Introduction

• The teacher explains the aim of the lesson and together with students determines the success criteria to be achieved.

Realization

• The teacher asks students to read the abstract themselves, paying particular attention to the illustrations.

• The teacher indicates the persons who, based on resources from the abstract, will in turn discuss the following issues: the process of energy flow through the ecosystem; energy efficiency of organisms located on the next trophic levels; the process of circulating matter in nature; circulatory disturbance of matter in ecosystems caused by irrational human activity; use of compost as an example of counteracting circulatory disturbance of matter in artificial ecosystems.

• Working with the brainstorming method, students try to determine the effects of regular lawn mowing and no fertilizer. Students analyze the consequences that all living organisms can feel..

• The teacher displays an illustration of „Detritus used as manure (horse feces and hay)”, explains to pupils what detritus is. Then, he asks the students to supplement the diary of observations, considering the matter circuit in detritus..

• Students carry out the interactive exercises checking the level of knowledge learned during the lesson. The teacher initiates a discussion during which the correct solutions for all the exercises performed by the students are discussed.

Summary

• At the end of the class, the teacher asks the students questions:

  • What did you find important and interesting in class?

  • What was easy and what was difficult?

  • How can you use the knowledge and skills you have gained today?

  Willing/selected students summarize the lesson.

Homework

• Listen to the abstract recording at home. Pay attention to pronunciation, accent and intonation. Learn to pronounce the words learned during the lesson.

The following terms and recordings will be used during this lesson

Terms

Texts and recordings

Ecosystem –the flow of matterr and the flow of energy

The energy of the sunlight is the base of the functioning of nature. The plants transform barely 1% of the energy of the sunlight that reaches their surface into chemical energy. This fraction of energy is stored in organic compounds and is enough for the producers to produce 150 bilion tonnes (150x10Indeks górny 12¹² kg) of biomass.

The majority of the energy stored in the organic compounds is used by the plant to satisfy its basic needs of life, mainly breathing, but also the synthesis of the necessary organic compounds, or the transport of substance. None of the processes that happen in the cell is 100% effective, so a huge part of this energy is dispersed in the form of warmth. As an effect, only a fraction of the energy of the sunlight, which is absorbed by a plant during photosynthesis, is stored in chemical bonds of organic compounds of which the body of a plant is build.

Herbivores don’t eat entire plants, moreover, most of them are unable to digest cellulose. Because of that, they receive only a part of the energy stored in the plant. They use it to maintain their own life processes, which also causes loss of the energy, just like it’s in the case of plants. To the last trophic level, which is the level of decomposers, goes the energy present in the remains of dead organisms and in faeces, especially in the indigestible body parts such as feathers, bones and horns.

On every level of the food chain, the majority of the absorbed energy is dispersed and lost. It is estimated that every subsequent trophic level disposes of circa 90% less energy than the previous level. That means that the energy flows through the ecosystem, in which it’s used and dispersed.

Plants (and other producers) are a bond between the world of inanimate and living matter. It forms organic compounds, which build the bodies of plants, using simple inorganic substances. It moves through the food chain in the form of aliment, and finally reaches the decomposers. Here takes place another important phase of circulation of matter: microorganisms decompose the organic substances to simple mineral compounds, which can again be absorbed by producers. Matter is never actually lost or dispersed in the ecosystem – it only changes the form. Natural ecosystems are self‑sufficient. Thanks to the continuous circulation the matter is constantly transformed and used again. No redundant substances are formed, and substances don’t have to be provided from external sources.

In artificial ecosytems, eg. farmlands, the circulation of matter is distorted. Humans collect and export almost the entire crop. In case of wheat, there are fruits (grain) as well as stems (straw). This ecosystem cannot function without supplying mineral fertilizer to the soil.

Gardeners produce the natural fertilizer, which accelarates the natural processes, on their own. They gather the remains of plants in the composter, providing conditions necessary for their decomposition. The fertilizer that is produced, can be used to fertilize the soil already in the next year.

• The source of energy in natural ecosystems is the sunlight.

• Energy flows through all of the levels of the food chain and is gradually dispersed in the environment. Its losses are compensated by the continuous energy supply from the Sun.

• In the ecosystems, the matter circulates between the living and inanimate of the ecosystem.