- Slides: 45
Ecology Chapter 3: The Biosphere
What Is Ecology? § Ecology- is the study of the interactions among organisms and between the organisms and the environments in which they live. (eco means “house”) . § Biotic factors – all living things § Ex. Types of plants, animals, bacteria, fungi, etc. § Abiotic factors – all non-living things § Ex. Climate, temperature, amount of rainfall, humidity, light, wind, soil type, nutrients available, etc.
Ecological Levels of Organization Smallest Largest Individual Population Community Ecosystem Biome Biosphere Go to Section:
§ § § Levels of Organization Summary Species-or individual Population- all of one species Communities-all populations Ecosystems- all populations + environment Biome- large stable ecosystems § Biosphere- Part of Earth where life exists (all biomes)
Species / Individual § A group of similar looking organisms that can breed with one another to produce fertile offspring.
Populations § Groups of individuals within the same species that live in the same area (habitat).
Communities § All Populations of various species that live together in a defined area.
Ecosystems § all members of a community & the physical environment they live in § What abiotic factors are present? § What biotic factors are present? • Habitat: place where an organism lives
Biome § large, stable groups of ecosystems that share the same biotic and abiotic factors Highlighted Regions Tropical Rainforest
Biosphere § The part of Earth where life exists.
What term is used to refer to each of the following? _________1. Lake Houston (location) Habitat _________2. Mississippi river and all of Ecosystem the forms of life that are sustained by it Population/species _________3. A flock of ducks Biome _________4. The Sahara desert Biosphere _________5. All livable areas on Earth Community _________6. All the deer, ducks, shore birds, fish and rabbits in an area
Practice: Species / Individual Population Community Ecosystem
§ The flow of energy through an ecosystem begins with the SUN, and is passed on through various organisms Sunlight Producers Consumers Decomposers
Sunlight Producers Consumers Decomposers Producers: Producers autotrophic organisms that are able to make own food from a inorganic substances. Ex. Plants, algae (phytoplanktonmicroscopic marine plant life)
Consumers: Sunlight Producers Consumers Decomposers § Consumers: heterotrophic organisms that get energy by eating producers and other consumers. (ex. Deer, hawk, bear)
Consumers: Sunlight Producers Consumers Decomposers Herbivores: eat producers (plants) ex. Deer, grasshopper, cow Carnivores: eat other consumers (meat) ex. Frog, wolf, hawk Omnivores: eat producers and consumers ex. Grizzly bear, humans Detritovore: organic wastes and dead bodies of plants and animals…. ex. mites, ` earthworms, snails, crabs, vultures
Consumers: Sunlight Producers Consumers Decomposers Level of Consumers: Primary consumer Secondary consumer 3 rd, 4 th …level consumer Herbivore Carnivore __________________ Omnivore & decomposers ____________ can be 1 st, 2 nd or higher level consumer
Sunlight Producers Consumers Decomposers: § Obtain energy from eating the remains of other organisms (recyclers) Ex. • Two Principle Decomposers: Bacteria and Fungi Worms Bacteria Fungi Termites Earthworms and termites (detritivores) also aid in the breakdown of organic matter, which replenishes nutrients to the soil.
Feeding Relationships Decomposers 1 st 2 nd 3 rd 4 th 5 th Each step in the food chain or web is called a trophic level, or a feeding relationship between organisms. What is always found at the second trophic level?
Food Chains § Food Chain a series of steps in which organisms transfer energy by eating and being eaten. Energy flows to The arrows show the flow of energy and matter as one organism is eaten by another.
Trophic Levels 5 th 4 th consumers Top Carnivores 3 rd consumers Carnivores 3 rd Secondary consumers Carnivores 2 nd Primary consumers Herbivores 1 st Producers
Food Webs § Food Web: links all the food chains in an ecosystem together. § Any change in a population or trophic level of a food chain can seriously alter all other organisms of the food web! § A healthy ecosystem has a large diversity of life because of the availability of alternative food sources. When studying the overall health of an ecosystem, we study food webs.
: e ic t ac Pr 1. What would happen to this food web is the plants §All populations would die out were removed? ______________ 2. Which organism is most vulnerable to changes in §The frog has only one food source populations? _______________ 3. What happens to the owl population if the foxes we killed off by humans? ____________ §The owl pop. would increase
We can show what goes on with the help of a Food Web
What would happen if a disease killed off many of the hawks?
There will be nothing to eat the snakes, so their numbers will increase.
All the frogs get eaten
No frogs. More crickets
Most of the cattail gets eaten by the crickets
Now the crickets don’t have enough food so their numbers go down
. . and so on. Numbers of each species have an effect on the numbers of the other species in the web.
ECOLOGICAL PYRAMIDS § Ecological Pyramids: show relative amounts of energy or matter contained within each trophic level in a food chain or food web.
Energy Pyramid: Kcal= kilocalorie A pyramid of energy illustrate the loss of usable energy at each feeding level. Of all the energy consumed by one level, 90% of the energy is used in the individual’s metabolism. (and lost as heat) Only about 10% of the energy available within one trophic level is transferred to organisms at the next trophic level. (locked in body tissues) 1 Kcal: Humans 10 Kcal: tuna 100 Kcal: zooplankton 1000 Kcal: plankton Why do most food chains have no more than 4 or 5 trophic levels? There is very little energy transferred to support higher trophic levels
Pyramid of Numbers § show many individuals are required to support the next level of feeding. Why must there be so many more individuals at lower trophic levels? Higher trophic levels have to eat more to get the same amount of energy due to the 10% rule.
Water and Nutrient Cycles § Energy cannot be recycled or used again. § However, nutrients/elements in an ecosystem can be recycled. § When an animal dies, its matter does not disappear; rather, it decomposes and gets used by another organism (through biogeochemical cycles). § This occurs through the water cycle, carbon cycle, nitrogen cycle, and phosphorous cycle.
The Water Cycle 1. According to the diagram, where does evaporation take place from? From Lakes and oceans 2. When water evaporates from the surface of the Earth, what process creates clouds? Condensation 3. Water falls to the earth in a process called precipitation. What are the 4 types of precipitation? Rain, snow, sleet, hail
The Water Cycle 4. Plants return excess water to the atmosphere by evaporating water from its leaves in a process called: Transpiration 5. Animals return water by urination, perspiration, and respiration. 6. Other than plant and animal usage, what are other destinations for the precipitation that falls to the Earth? It can become surface runoff or groundwater 7. What will ultimately happen to the ground water and surface water runoff? It flows back to lakes and rivers to be evaporated again.
The Carbon Cycle 1. Name and discuss the process that removes carbon dioxide from the atmosphere? In photosynthesis, producers remove CO 2 gas from the atmosphere to make organic molecules (sugars).
The Carbon Cycle 2. Name and discuss the processes in which carbon dioxide is returned to the atmosphere? Cellular respiration Animals burn the food they eat releasing CO 2 gas as a waste product. Combustion: Burning Fossil Fuels. When they are burned, CO 2 gas is returned to the atmosphere and increases the amount of CO 2 gas in the air.
The Carbon Cycle 3. How is carbon dioxide related to the green house affect? Carbon dioxide, methane, and other gases trap heat energy and maintain Earth’s Temperature range.
The Carbon Cycle 4. It is thought that global warming is caused by adding carbon dioxide to the atmosphere. What activities (by human or natural causes) are thought to speed up global warming? Burning fossil, cutting down forest, and polluting oceans (most photosynthesis occurs in oceans)
The Nitrogen Cycle • Air is 78% nitrogen • Nitrogen is one of the elements found in plant fertilizers • Protein contains nitrogen 1. Bacteria living in the roots of the plant help the plant by convert nitrogen gas to ammonia 2. Bacteria living in the soil help plants by converting ammonia and nitrogen gas into nitrates and nitrites. 3. What process transforms nitrogen into usable forms tha plants can use? Nitrogen fixation 4. What do plants use these nitrates and nitrites to make? Proteins
The Nitrogen Cycle • Air is 78% nitrogen • Nitrogen is one of the elements found in plant fertilizers • Protein contains nitrogen 5. Where do animals ultimately get their proteins from? Plants 6. How has farming affected the nitrogen cycle? Fertilizers add nitrogen compounds to soil for plants to use. 7. How has industry affected the nitrogen cycle? Burning fossil fuels release nitrogen compounds that fall to the earth as acid rain.