Unit 2 – Natural Systems

1. Unit 2 – Natural Systems The Earth’s Spheres and Ecosystems

2. The Earth’s Spheres • Looking at the following components: • Lithosphere • Hydrosphere • Atmosphere • Biosphere • Open System • Closed System

3. The Earth’s Spheres • Lithosphere is the solid outer crust of the earth • The lithosphere runs up to 60 miles deep, is divided into the crust and upper mantle. • The upper part of the crust is made of igneous and sedimentary rocks; this makes up the continents. • The lower crust is made of igneous rocks which form the ocean floors. • The inner layers of the earth are the mantle and the core

4. The Earth’s Spheres • Lithosphere is the outer part of the earth, consisting of the crust and upper mantle.

5. The Earth’s Spheres • Hydrosphere is the part of the Earth composed of water (including clouds, oceans, seas, ice caps, glaciers, lakes, rivers, underground water supplies, and atmospheric water vapour). • Approximately 71% of the Earth is covered by water. • 97% of this water is in the oceans (salt water) • 3% is freshwater • 77% of freshwater is locked in ice • 22% of freshwater is in the ground • <1% of freshwater is in lakes, rivers, and wetlands

6. Hydrosphere

7. The Earth’s Spheres • Atmosphere is the mixture of gases surrounding the Earth and other planets. • Thermosphere • Mesopause • Mesosphere • Stratopause • Stratosphere • Tropopause • Troposphere

8. The Earth’s Spheres • Biosphere is the life zone of the Earth and includes all living organisms, including man, and all organic matter that has not yet decomposed. • The biosphere is structured into a hierarchy known as the food chain whereby all life is dependent upon the first tier (i.e. mainly the primary producers that are capable of photosynthesis).

9. Biosphere con’t… • All organisms are intrinsically linked to their physical environment and the relationship between an organism and its environment is the study of ecology. • The biosphere can be divided into distinct ecosystems that represent the interactions between a group of organisms forming a trophic pyramid and the environment or habitat in which they live.

10. The Earth’s Spheres • Biosphere is the combination of the lithosphere, hydrosphere, and atmosphere that can support life.

11. The Earth’s Systems • It is important to understand how the various parts of our Earth’s systems interact in order to create solutions for environmental problems. • An open system is one where both energy (heat) and matter can be exchanged (e.g. oceans – water is evaporated into atmosphere) • A closed system is one where only energy (heat) can be exchanged (e.g. soil/land – heat absorbed and released during day and night)

12. Ecosystems Key Terms… • Ecosystem: all different organisms living in a certain area along with their physical environment e.g. Soil ecosystem (earthworms, snakes, moles, insects, plants, fungi and bacteria) * Think of an ecosystem like a car, everything in a car works together to make it work, if one part breaks the car might not work! • Abiotic: the non-living parts of an ecosystem e.g. Temperature, sunlight, humidity, minerals, water supply and soil type • Biotic: the living parts of an ecosystem which interact with one another as well as the abiotic factors e.g. Plants, animals and microorganisms

13. How Does an Ecosystem Fit Into the Organization of Living Things? An individual organism is part of a population, a community, an ecosystem, and the biosphere.

14. Ecosystems Key Terms… • Organism: one individual living thing e.g. a person, ant, gorilla, flower, bacterium • Species: a group of organisms that are able to produce fertile offspring, that share common genes and therefore resemble each other e.g. Humans are of the species Homo sapiens Domestic dogs are of the species Canis familiaris • Populations: a group of individuals of the same species living in a particular place e.g. Bullfrogs in a pond, lions in a savanna, flowers in a field • Communities: consists of a group of interacting populations of different species of organisms e.g. All living inhabitants of an ecosystem make up a community Pond - includes populations of fish, plants, insects, amphibians, and microorganisms

15. Ecosystems Key Terms… • Niche: an organism’s way of life including all interactions with both living and non-living parts of its environment (lifestyle) e.g. A lion’s niche might include: a) a tick on the lion’s face b) the lion fighting with hyenas c) the lion feeding on prey d) the lion drinking at the water hole • Habitat: the actual place an organism lives e.g. Cactus – desert, Water Lily - pond

16. EcosystemsAre Made Up Of Abiotic Partssuch as… Biotic Partssuch as… Habitats which live in Sunlight Temperature Water Organisms which are a part of which act in Niches Populations which are a part of Communities

17. Flow of Energy • Photosynthesis: biological synthesis of chemical compounds in the presence of light; produces organic substances such as sugar e.g. the way plants produce energy • Respiration: breaking down food to yield energy e.g. you eat food, your body uses the oxygen you breathe to break down food molecules releasing energy