Topic: Ecosystem of the forest, ecosystem of the lake

Author: Leokadia Stalewicz

Target group

8th‑grade students of elementary school

Core curriculum

General requirements

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

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

Specific requirements

VII. Ecology and environmental protection. Student:

1. indicates the living and non‑living elements of the ecosystem and shows that they are related to various dependencies.

General aim of education

You will learn the specificity of the forest ecosystem and the ecosystem of the lake

Key competences

• communication in foreign languages;

• digital competence;

• learning to learn.

Criteria for success
The student will learn:

• indicate the living and non‑living elements of the ecosystem;

• indicate the relationship between animate and non‑living elements of the ecosystem;

• give examples of how organisms affect the inanimate part of the ecosystem;

• describe the structure of the forest and lake ecosystem.

Methods/techniques

• expository

  • talk.

• activating

  • discussion;

  • brainstorming.

• 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.

• Then he writes the subject of the lesson on the blackboard or interactive whiteboard. Students write it in notebooks.

• The teacher informs the students that in the classes they will investigate how the organisms in the ecosystem interact with each other.

Realization

• Using the resources of the „Forest ecosystem” lesson and the interactive illustration of „Forest strata”, the lecturer discusses the storied forest structure and provides a brief description of each floor.

• Working with the brainstorming method, students exchange as many species living in the temperate forest, including all possible groups of animals. Then, through an open discussion, the class analyzes the relationships between these organisms..

• Using the resources of the „Lake ecosystem” lesson, the teacher discusses the division of the lake into zones and gives examples of organisms living in each of these zones.

• Working in pairs or small groups, students search in available sources for basic information about Lake Victoria in Africa. Then they determine if the description of the lake presented in the lesson also applies to Lake Victoria. Each pair or group in turn presents its arguments. If the opinions of the students are divergent, the teacher explains all doubts and indicates the correct answer. For example, in Lake Victoria, it is difficult to distinguish the littoral zone and the midwater, the bentic zone can take the form of a rocky, sandy or muddy.

Summary

• The teacher asks students to carry out the recommended interactive exercise themselves.

• At the end of the lesson the teacher asks: If there was going to be a test on the material we have covered today, what questions do you think would you have to answer? If the students do not manage to name all the most important questions, the teacher may complement their suggestions.

Homework

• At home, look for information about introduced species of animals and plants in Lake Victoria..

The following terms and recordings will be used during this lesson

Terms

Texts and recordings

Ecosystem of the forest, ecosystem of the lake

Primeval forest is an example of a naturally formed and stable terrestrial ecosystem. Such ecosystems can be found in almost every part of the Earth. Depending on the latitude, we distinguish rainforests, taigas, or mixed forests in temperate regions. Factors that affect the organisms constituting an ecosystem include average annual temperature, seasons, and soil moisture. Trees growing in different climate zones have adjusted accordingly to make the best use of the sunlight available.

The forest ecosystem is characterised by stratification, which is the result of plants competing for sunlight access. There are four strata in a temperate zone hardwood forest: plant litter, ground cover, understorey, and canopy. A rainforest has more strata.

The lowest stratum is called the plant litter. It consists of dead organic matter, mainly plant remains. Due to the presence of saprobionts such as bacteria or fungi, decomposition processes are constantly taking place, as a result of which organic matter is transformed into forest soil. Large amounts of heat are released in the process, fostering the development of invertebrates living in this strata. The amount of plant litter depends on the activity of decomposers. Therefore, there is very little to no plant litter in warm climate, where decomposition happens very fast, while in taiga it forms a thick layer. For this reason, taiga soil, unlike rainforest soil, is of fertility.

Every year, the thicket produces huge amounts of organic matter, which serves as food for many heterotroph species. Every species has its own place in the forest system and is connected to the environment and other species in many different ways.

Similarly to forests, lakes also have different layers depending on the depth, with varying levels of sunlight access. There are three groups of organisms inhabiting a lake: those that live at the bottom, active swimmers, and those that float freely in midwater.

The littoral zone is located close to the shoreline. Water here is shallow and receives a lot of sunlight during daytime. In consequence, it is warm on a sunny day, and cools down quickly during the night. In winter, water in the littoral zone freezes. Due to the shallowness and waves caused by the wind, the water is well‑oxygenated, which together with sunlight fosters the development of various organisms. Plants that grow by the shore—ditch reed, sweet flag—are rooted in the lake bottom immediately below the water surface. Those that grow further from the shore—nymphanea, nuphar—do not grow high above the surface, just enough to develop their leaves above it, with roots in the lake bottom. Even further from the shore, underwater plants can be found—pondweed, Canadian waterweed. Many animals live in the littoral zone: aquatic insects and their larvae, fry, tadpoles, fish such as pike, perch, roach, amphibians—frogs and newts—and many species of birds.

The midwater receives varying amounts of sunlight, depending on the depth and transparency of water. Relatively high fluctuations of the temperature and oxygenation appear close to the surface, but the conditions stabilise with depth. Fewer animals live here than in the littoral zone, and no plants are rooted in the bottom. The inhabitants of this zone include grayling and zander, as well as great crested grebe and great cormorant. Under the surface, many small organisms float, known as plankton.

Not much sunlight or oxygen reaches the benthic zone. The range of temperatures is narrow here. In winter, when the surface water is frozen, the temperature near the bottom remains at a stable 4°C, approximately. There are no plants in this zone; only bacteria, protists, and animals. Most of them feed on dead organic matter that falls onto the bottom. Many, like mussels, filter out food particles from the water. At the lake bottom, demersal fish can be found, mainly eels. Some animals, such as frogs, spend the winter hidden in the mud at the bottom.

• An ecosystem is the combination of abiotic environment with all the populations of different species inhabiting it, as well as the processes and interactions between themselves and between them and the inanimate environment.

• In an ecosystem, the environment affects individual species of animals, and those change the environment in turn.

• Ecosystems can be divided into artificial and natural, or terrestrial and aquatic.

• The structure of a forest ecosystem is based on strata.

• The structure of a lake ecosystem is dependent on water depth and transparency.

• A lake consists of three main zones: littoral zone, midwater, and benthic zone.