Natural ecosystems and human activities

Topics

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Sample objectives

What this unit covers

• Ecosystems: Students should be able to: • explain the concepts of ecosystem, population, community, habitat, and niche • outline the living (biotic) and non-living (abiotic) elements of an ecosystem, including: biotic factors such as producers, primary, secondary, and tertiary consumers, and decomposers; abiotic factors such as temperature, humidity, water, oxygen, salinity, light, and pH • discuss interactions among living organisms, including competition, predation, and pollination • explain the process of photosynthesis and the role of chlorophyll, including the relevant word equation • illustrate energy transfer through food chains, food webs, and trophic levels • describe and interpret ecological pyramids in terms of numbers and energy • explain the process of respiration and its word equation • outline the carbon cycle.
• Ecosystems under threat: Students should be able to outline and clarify the reasons and effects of ecosystems being endangered, including: causes such as wetland drainage, intensive agricultural practices, and deforestation; and effects like biodiversity loss, genetic depletion, and extinction.
• Deforestation: Students should be able to describe and explain the reasons behind deforestation and its effects. Reasons include timber extraction and logging, subsistence and commercial agriculture, the construction of roads and settlements, and the extraction of rocks and minerals. Effects include the loss of habitats, soil erosion and desertification, climate change, and the reduction of biodiversity and genetic diversity.
• Managing forests: Students should be able to describe and clarify the importance of sustainable forest management, including how growing forests function as carbon sinks and mature forests serve as carbon stores, their role in the water cycle, their contribution to preventing soil erosion, their significance for biodiversity as a genetic resource, and their provision of food, medicine, industrial raw materials, and opportunities for ecotourism.
• Measuring and managing biodiversity: Students should be able to describe and assess various techniques for estimating biodiversity, including the use of pitfall traps, pooters, quadrats, and transects, as well as random and systematic sampling methods. They should apply these sampling techniques to new scenarios and evaluate both national and international strategies for conserving biodiversity and genetic resources, such as sustainable harvesting of wild species, sustainable forestry and agroforestry, national parks, wildlife reserves, extractive reserves, biosphere reserves, seed banks, and the roles of zoos and captive breeding, along with sustainable tourism and ecotourism. Case studies should include the examination of deforestation causes and effects in a specific area, the conservation of a particular species, and the study of a designated biosphere reserve. Additionally, students should be able to formulate aims and hypotheses, design effective questionnaires for data collection, create simple experiments with appropriate controls, and understand the evaluation of sampling techniques. They should also be proficient in mathematical skills, including basic operations, averages, percentages, ratios, and the interpretation of data through tables, charts, and graphs, as well as understanding geometric terms and map scales.