Y8 Unit 4 Ecosystems PDF

Unit 4 Ecosystems 4.1 The Sonora Desert 4.2 Different ecosystems 4.3 Intruders in an ecosystem 4.4 Bioaccumulation Ecosystem: is the interaction between living organisms (biotic factors) and non-living things (abiotic factors) around them. ECOSYSTEM B...

Unit 4 Ecosystems 4.1 The Sonora Desert 4.2 Different ecosystems 4.3 Intruders in an ecosystem 4.4 Bioaccumulation Ecosystem: is the interaction between living organisms (biotic factors) and non-living things (abiotic factors) around them. ECOSYSTEM BIOTIC FACTORS ABIOTIC FACTORS LIVING THINGS NON-LIVING THINGS 1. Animals 1. Sunlight 2. Plants 2. Water 3. Fungi 3. Air 4. Bacteria 4. Temperature 5. Soil 4.1 The Sonoran Desert A desert in Arizona: A land of resilience, adaptation, and breathtaking beauty. Harsh Environment: Deserts in Arizona, USA, pose challenges for both plants and animals due to minimal rainfall. Adaptations of Saguaro Cacti: Slow- growing saguaro cacti, over 100 years old, with wide-reaching roots for water absorption. Diverse Wildlife: Gila woodpeckers and other birds' nest in cacti, while cactus wrens prefer teddy bear cholla for protection. 4.1 The Sonoran Desert A desert in Arizona: Survival Strategies: During hot days, animals seek shade or cooler soil, while kangaroo rats emerge at night to feed. Impact of Rainfall: Periodic heavy rains transform the desert, triggering rapid plant flowering. Insects pollinate flowers, and bats feed on agave nectar. Seed Dispersal: Ants collect and store seeds, leading to potential germination and new plant growth. 4.1 The Sonoran Desert Interactions in the Sonoran Desert: Mutual Dependency: Animals and plants in the Sonoran Desert rely on each other for survival. Interconnected Ecosystem: Each organism's actions impact others within the ecosystem. Symbiotic Relationships: Mutualistic interactions between species ensure the sustainability of the desert ecosystem. Balance of Nature: The delicate balance of interactions maintains the health and diversity of the Sonoran Desert. 4.1 The Sonoran Desert Interactions with Non-Living Environment: Organisms in the Arizona desert interact with both living and non-living components of their environment. Non-living components include: Light: Bright sunlight facilitates photosynthesis in plants, providing food for other organisms. Temperature: Diurnal temperature variations influence animal behavior, with some species being nocturnal to avoid daytime heat. Soil: Rocks and soil serve as mineral sources for plant growth and building material for ground-nesting birds. Water: Essential for cellular survival, water activates desert life and facilitates reproduction upon rainfall. Air: Desert air supplies carbon dioxide for photosynthesis and oxygen for respiration. 4.1 The Sonoran Desert The desert ecosystem: Food webs: When all the food chains in an ecosystem are joined together. Represents multiple pathways through which energy can flow through an ecosystem. A Food Chain shows how energy if transferred from one organism to another. The arrows show the direction of the energy transfer. 4.1 The Sonoran Desert The desert ecosystem: Ecology: The study of ecosystems Habitat: place where an organism lives. Adaptations: features of an organism that help it to live and survive in its habitat. ❑ Adaptations help organisms to live successfully in their environment. ❑ If humans destroy or alter habitats, then the populations could decrease drastically or become extinct. ❑ Once a species becomes extinct it can never exist again. ❑ In June 2019, one million species of plants and animals were at risk of extinction. 4.1 The Sonoran Desert Herbivores eat plants. Carnivores eat meat. Omnivores eat plants and meat. A producer is an organism that creates its own food or energy. (Producers, also called autotrophs, include plants, bacteria, and algae. Plants get energy from the sun and turn it into food, a sugar called glucose). A consumer is an organism that gets its energy by eating plants or animals. Predator: an animal that kills and eats other animals. Prey: animals that are killed and eaten by other animals. 4.2 Different ecosystems Examples of different ecosystems: Mangrove forest: Inside the Mangrove Forest - YouTube Sea ice in the Artic Ocean: Exploring the Arctic for Kids: Arctic Animals and Climates for Children - FreeSchool - YouTube Rice paddy: Remarkable Rice: how does rice grow - YouTube 4.3 Intruders in an ecosystems Key Words: Eradicate: get rid of or totally destroy Extinct: organisms no longer exist Native species: organisms living in their natural habitat. Invasive species: Species that are introduced into an ecosystem that they do not belong in. An invasive species is any kind of living organism that is not native to an ecosystem and causes harm. Can grow and reproduce rapidly and aggressively. Can harm the ecological balance, biodiversity, human health. Can lead to extinction of native species. How Lionfish Took over the Mediterranean Sea - YouTube 4.4 Bioaccumulation Dichlorodiphenyltrichloroethane (DDT): DDT is an insecticide used in agriculture. This means that it kills insects. DDT is very harmful to many kinds of animal. It is toxic (poisonous). It is a persistent chemical. It stays in the environment for many years. DDT does not break down not even by decomposers which feed on dead things (dead plant materials such as leaf litter and wood, animal carcasses, and faeces) 4.4 Bioaccumulation Bioaccumulation and biomagnification: Bioaccumulation is the gradual increase of a substance in an organism's body. o This happens when the substance cannot be broken down inside the body cells. o Chemicals consumed / absorbed, and the body cannot catabolize (breakdown of complex molecules to form simpler ones, release energy) or excrete them quickly enough e.g. Mercury 4.4 Bioaccumulation Bioaccumulation and biomagnification: Biomagnification is the increase in the concentration of a substance as you go up the food chain. o When predatory animals consume their prey they also consume all of the toxic chemicals within it. o When these toxins aren't easily excreted they build up in the animal's system through bioaccumulation. o Therefore, when the food chain progresses, concentrations increase. Biodegradable and Non-Biodegradable items Biodegradable items: any material which is broken down and decomposed by microorganisms. E.g. vegetable and fruit peels, dead plants/animals, eggshells, garden waste, paper materials Non-Biodegradable items: Incapable of being broken down by living organisms. e.g. plastics, polythene bags, insecticides, pesticides, mercury, lead, aluminium cans, glass objects, iron products and silver foils. (Degradable products are mostly oil-based and they break down through chemical reactions rather than organically by microorganisms.)