Biosphere: Living Earth

Biosphere

The part of Earth that supports life is thebiosphere. It includes the top portion of theEarth’s crust, all the waters that cover Earth’ssurface, and the atmosphere that surroundsEarth.

The biosphere is divided into large geographicareas that have similar climates and ecosystemscalled biomes.

What are the 5 major categories of biomes?

Biosphere

Aquatic, desert, forest, grassland, tundra

Biosphere

Each biome is divided into smaller areas calledecosystems.An ecosystem consists of all the organisms livingin an area, as well as the nonliving parts of thatenvironment.Ecology is the study of interactions that occuramong organisms and their environment.Ecologists are the scientists who study theseinteractions.

Interactions of Life

The living parts of an environment are calledbiotic factors.

Biotic factors means everything that is alive orwas once alive.

The living world (an ecosystem) is arranged inseveral levels of organization.

An organism- a living thing

A population- all organisms of the same species that live inan area at the same time

A community- all the populations of all species living in an ecosystem

Interactions of Life

Organisms

Each organism in an ecosystem needs a specialplace to live; this is the organism’s habitat.

Each organism also has a role in itsenvironment- how it obtains food and shelter,finds a mate, cares for its young, and avoidsdanger. This is the organism’s niche.

Populations and Communities

Organisms within populations and communitiesinteract with one another in several types ofrelationships.

1. Competitive2. Symbiotic3. Predator & Prey4. Cooperation

Competitive Relationships

Organisms living in the wild do not always haveenough food or living space.

Competition occurs when two or moreorganisms seek the same resource at the sametime.

http://www.youtube.com/watch?v=yhZ0TKdgJGg

Competition for food, living space, and otherresources can limit population size and growth.

Competitive Relationships

Example of a Competitive RelationshipChapter 4 pg. 98 Figure 5

The Gila woodpecker lives in the Sonoran Desert of Arizona and Mexico. It makes its nestby drilling a hole in a saguaro cactus. The woodpeckers must compete with each other for nesting spots. Many animals compete for the shelter these holes provide. If available nesting spaces are limited, some wood peckers will not be able to raise young. The woodpeckers eat cactus fruit, berries, and insects.

Questions

1. The most intense competition is among what individuals? Why?

2. What might happen to the woodpeckers if

food becomes scarce?

3. What does this mean for the woodpeckers population?

The most intense competition will be amongorganisms of the same species because they need the same food and shelter.

Some woodpeckers might not survive to reproduce.

The population of woodpeckers would decrease.

Population Size

Ecologist often need to measure the size of apopulation. This information can help themdetermine if a population is healthy and growingor if it is in danger of disappearing.

Ecologists use several methods for measuringpopulations.

Question

Why would people want to know the populationsize of organisms such as deer?

Ecologists may want the data for research. Game and fish departments may want the information to decide how many hunting permits to issue.

Factors That Affect Population Size

In any ecosystem, the availability of food, water,living space, mates, nesting sites, and otherresources is often limited. A limiting factor is anything that restricts thenumber of individuals in a population.A limiting factor can affect more than onepopulation in a community.

Example of Effects of Limiting FactorsA population of robins lives in a grove of trees ina park. Over several years, the number of robinsincreases and nesting space becomes scarce. Nesting space is a limiting factor the prevents therobin population from getting any larger. Thisecosystem is supporting all the robins it can. If therobin population continues to increase, some willnot have enough resources to survive. They coulddie or be forced to move to another location.

When an ecosystem is supporting the largestnumber of individuals of one species that it can,it has reached its carrying capacity.

Factors That Affect Population Size

Question

Think about a population that is living underideal conditions. It has an unlimited supply offood, water, and living space. The climate isfavorable. There are no diseases, predators, orcompetition.

What would happen if no limiting factorsrestricted the growth of the population?

The population will continue to grow.

Changes in Population

The highest rate of reproduction under idealconditions is a population’s biotic potential.The larger the number of offspring that areproduced by parent organisms, the higher thebiotic potential of the species will be.

Tangerine Avocado

Which organism has the highest biotic potential?Why?

When a species birthrate is higher than its deathrate, the population will grow. When the death rate is higher than thebirthrate, the population growth will slow down. When a species has plenty of food, living space

and other resources, the population grows quickly in a pattern called exponential growth. Exponential growth means that the larger a population gets, the faster it grows.

Changes in Population

Chapter 4 page 104 Visualizing Population Growth

Symbiotic Relationships

Many organisms live together and shareresources. Any close relationship betweenspecies is called symbiosis.

There are 3 types of symbiotic relationships.1. Mutualism- both organisms benefit

2. Commensalism- one organism benefits and the other is not affected

3. Parasitism- one organism benefits but the other is harmed

Predator & PreyPredators are consumers that capture and eat otherconsumers.

The prey is the organism that is captured by thepredator.

Predator & Prey

The presence of predators usually increases the number of different species that can live in an ecosystem. Predators limit the size of the prey populations. As a result, food and other resources are less likely to become scarce, and competition between species is reduced.

Knowing this, is the alligator hunting season, likethat depicted on Swamp People, positive for thebiodiversity of the ecosystem, negative for thebiodiversity of the ecosystem, or both?Explain your reasoning! Justify your response!

Question

http://www.history.com/shows/swamp-people/videos/the-truth-about-gators#the-truth-about-gators

http://www.history.com/shows/swamp-people/videos/the-truth-about-gators#future-of-gator-hunting

Cooperation

Often, organisms cooperate in ways thatimprove survival.

http://animal.discovery.com/tv-shows/wild-kingdom/videos/prairie-dogs-sound-the-alarm.htm

Nonliving Environment

The nonliving parts of an environment are called abiotic factors. Abiotic factors include air, water,soil, sunlight, temperature and climate. Abioticfactors are important features in the cycling ofwater, carbon, nitrogen, and energy which areall essential for life.

The law of conservation of energy states thatenergy is not created or destroyed, but onlyconverted into other forms of energy.

Nonliving EnvironmentEnergy Flow: Conservation of Energy

http://www.youtube.com/watch?v=vX07j9SDFcc

http://www.youtube.com/watch?v=rG0aNqeMNIk

Food Chain: A way of showing how matter and energy pass from one organism to another

Food Web: A model that shows all the possible feeding relationships among the organisms in a community; made of many different food chains.

Energy Pyramid: Shows the amount of energy available at each feeding level in an ecosystem

Nonliving EnvironmentEnergy Flow: Conservation of Energy

Food ChainChapter 5 page 137 Figure 15

Question: Infer what might happen if grizzly bears disappeared from this ecosystem.

The population of marmots will increase to a level that cannot be supported by the food supply.

Food WebChapter 5 page 138 Figure 16

Task: From the food web, name three different food chains.

Question: What is the impact on other organisms if the grouse is removed from the food web?

If the grouse is removed, there will be more berries and flowers for the deer to eat.There will be more insects and seeds. The food supply for the Red-tailed hawk will not beas plentiful or diverse. More food for the chipmunks will be available. There may be less foodfor the marmot.

Energy PyramidChapter 5 page 139 Figure 17

Question: Describe what would happen if the hawks and snakes outnumbered the rabbits and mice in this ecosystem.

Less energy would be available to hawks and snakes. Eventually they would begin to die off until a balance was achieved unless they moved out of the ecosystem.

Outside FactorsDo you think you control the environment around you? You know that you can't control the weather or the tides. However, you do have a huge influence over your local ecosystem and the world. The term biosphere is used to describe all of the ecosystems found across the world. They are all there, from the bottom of the ocean, to the Antarctic mountains. There are large factors that influence all of the ecosystems. The easy factors to remember are climates, seasons, and natural disasters.

Humans - The Largest Factor?You affect the biosphere every day. Think about the people who still use coal to power generators in China. Did you know that they use so much coal that it goes into the atmosphere and floats around the entire world? It's like a huge band of pollution circling the Earth. Those people definitely affect the biosphere.

What about the farmer who uses a bunch of fertilizers? One person is just fertilizing his fields. All of those nutrients go into the soil, are washed away into the rivers, and finally make it to the ocean. Every step of that process changes the local ecosystem. When the fertilizer gets to the ocean, even more things may change. Let's say a huge number of bacteria grow on the extra nutrients. Those bacteria can make the fish sick and die. Eventually the bigger fish die because there is no food. Soon there are no fish to catch and over fishing happens somewhere else in the world. Do you see how one person can affect the entire planet?

Factors That Affect Biomes

Factors That Affect BiomesAquatic

Water PollutionWater QualityProtecting Diversity of Coral Reefs

Restoring Wetlands: many were drained anddestroyed to make roads, farmland, shoppingcenters, and housing developments.

Factors That Affect BiomesAquatic

Resources to refer to:• Editorial Cartoon• Chapter 6 Page 172 “Creating Wetlands to Purify Wastewater”

• In order to provide for desert cities, rivers andstreams have been diverted. When thishappens, wildlife tends to move closer to citiesin their search for food and water. • Education about desert environments has led to an awareness of the impact of humanactivities. • As a result, large areas of desert have been setaside as national parks and wilderness areas toprotect desert habitats.

Factors That Affect BiomesDesert

http://ots.blogs.bucknell.edu/2010/12/01/a-whole-lot-of-driving-part-i/

Forest Fires (Wildfires)

Factors That Affect BiomesForest

Resources to refer to:• Chapter 6 page 148 “The Benefits of Wildfires”

The 2000 fire season was long, difficult, and expensive. Over 120,000 fires burned more than 8 million acres in the United States, costing more than a billion dollars. The largest fire burned for over two months and

blackened almost 300,000 acres in western Montana. Many ecosystems rely on fire in order to regenerate themselves, so fire is beneficial and necessary for many ecosystems. (Excerpt from page 148 in Teacher’s Edition)

Resources to refer to:• Chapter 6 Page 152 “Visualizing Secondary

Succession”

Factors That Affect BiomesForest

At first, plants that need lots of sunlight can live on the forest floor, becausethere are no tall trees to block the sunlight. As trees grow and mature, there will be less sunlight penetrating to the forest floor, so species that require less light will be found.

As succession proceeds, what changes will occur in the population of plants found on the forest floor?

Secondary Succession

Factors That Affect BiomesForest

DeforestationProcess of clearing forests. Rates of deforestation are particularly high in the tropics, where the poor quality of the soil has led to the practice of routine clear-cutting to make new soil available for agricultural use. Deforestation can lead to erosion, drought, loss of biodiversity through extinction of plant and animal species, and increased atmospheric carbon dioxide. Many nations have undertaken reforestation projects to reverse the effects of deforestation, or to increase available timber.

http://www.merriam-webster.com/dictionary/deforestation

Reforestation Projects

Resources to refer to:• Editorial Cartoon• Deforestation Picture

Seasonal Fires Movie Clip

Overgrazing- can result in death of grasses andloss of valuable top soil from erosion. Mostfarmers and ranchers take precautions toprevent the loss of valuable habitats and soil.

Factors That Affect BiomesGrasslands

Overgrazing- Fences, roads and pipelines havedisrupted the migratory routes of some animalsand forced them to stay in a limited area.Because the growing season is so short, plantsand other vegetation can take decades torecover from damage.

Factors That Affect BiomesTundra

Threatened Species

Threatened means having an uncertain chanceof continued survival : likely to become anendangered species

http://www.merriam-webster.com/dictionary/threatened

Endangered-Any species of plant, animal, orother organism threatened with extinction.International and national agencies work tomaintain lists of endangered species, to protectand preserve natural habitats, and to promoteprograms for recovery and reestablishment ofthese species.

Endangered Species

http://www.merriam-webster.com/dictionary/endangered%20species

http://fw.kyenUTF8

Extinct Species

no longer existing : lacking living representativeshttp://www.merriam-webster.com/dictionary/extinct%20species

For a list of threatened and endangered species in Kentucky go to http://fw.ky.gov/telst.asp

Chapter 10 page 296 “Science Stats-Extinct!”Content Background and Discussion