7th Grade Ecosystems: The Sonoran Desert PDF

22/01/25 7th Grade ECOSYSTEMS: 4.1 The Sonoran Desert Science 1 Deserts are not easy places for plants and animals to live. In order to survive in deserts, plants and animals...

22/01/25 7th Grade ECOSYSTEMS: 4.1 The Sonoran Desert Science 1 Deserts are not easy places for plants and animals to live. In order to survive in deserts, plants and animals need to have adaptations Cactus adaptations: - Large stems to store water - Widespread root system to collect water easily - Thick waxy cuticle to prevent water loss - Spines instead of leaves- reduce the surface area for transpiration and protect them from predators 2 1  22/01/25 Animals adaptations Daytime (hot) - Burrow holes in the ground where is cooler Night time (temperature falls) - Come out to feed In Sonoran Desert, it rains heavily at least once a year, leading to transformations in desert., with plants producing flowers very quickly. Pollination happens during this period. Seeds fall on the ground and can be collected and stored by ants,. Can germinate later. 3 Non-living things in the desert Living things and non-living things interact in their environment. LIGHT TEMPERATURE SOIL WATER AIR 4 2  22/01/25 Desert ecosystem An ecosystem is a network of interactions between living organisms and non-living things. Some of the interactions involve food webs. The study of ecosystems is called ECOLOGY. 5 Habitats in a desert ecosystem The place where an organism live its is habitat. Habitat of cactus is the open desert Habitat of Gila woodpecker is the cactus (lives) and the air and the ground (collect food) Habitat of the desert ant is underneath the rocks and soil and soil surface … 6 3  22/01/25 4.2 Other ecosystems 7 Mangrove forest Mangrove are trees that grow their roots in sea water, forming forest along the coast of many tropical countries. Mangrove forests are unique ecosystems that bridge the land and the salt water of the ocean and are home to many species. Their roots provide protection for smaller fish 8 4  22/01/25 Sea ice in Artic Ocean Despite the harsh weather and the ice cover, the Arctic Ocean is teeming with life. It has a complex but abundance ecosystem that supports large predators such as walruses, polar bears and whales. 9 Rice paddy Not a natural ecosystem. This is an area farmed by people in Malaysia. At some time of the year, paddy fields are flooded with water. Algae grow in this shallow water. Because the water is shallow, heats up quickly during the day and cools down quickly during the night. Farmes often add fertilizers what makes rice to grow more as well as algae providing more food for animals. 10 5  22/01/25 4.3 Intruders in ecosystems 11 Native species Invasive species Types of organisms that are A species that has been living in their natural habitats introduced in an ecosystem where it does not belong 12 6  22/01/25 Consequences of invasive species Competition for food Competition for shelter Introduction of new diseases … 13 4.4 Bioaccumulation 14 7  22/01/25 DDT Insecticide Kills insects Produced in 1940 and is very useful killing insects. It is now known that it also cause damage to environment Doesn’t break down. It is a persistent chemical. When DDT gets into an animal body, it stays there for the whole life of the organism it never breaks down. 15 Bioaccumulation and biomagnification Bioaccumulation is the gradual increase of a substance in an organisms’ body. It happens when the substance can’t be broken down inside the body cells. Biomagnification is the increase of the concentration of a substance as you go up a food chain 16 8