Ecosystems: Everything Is Connected Chapter 7: Aquatic Ecosystems. Environmental Science and the Earth

Ecosystems: Everything Is Connected Example of the idea that “everything is connected” In 1995, scientists interested in controlling gypsy moths, which kill oak trees, performed an experiment. Photo by R. Jowsey

Everything Is Connected: Example The scientists removed most mice, which eat young gypsy moths, from selected plots of oak forest. The number of young gypsy moth eggs and young increased dramatically. http://news.nationalgeographic.com/news/bigphotos/images/071022-vibrating-mice_big.jpg

Everything Is Connected: Example The scientists then added acorns to the plots. Mice eat acorns, therefore the number of mice soon increased, and… The number of gypsy moths declined as the mice ate them as well. http://cakboliv.files.wordpress.com/2009/08/acorns_nut_mc_.jpg

Everything Is Connected: Example This result showed that large acorn crops can suppress gypsy moth outbreaks. http://images.suite101.com/608399_com_img_9740.jpg

Everything Is Connected: Example Oh but there is more!!! Interestingly, the acorns also attracted deer, which carried ticks. Young ticks soon infested the mice. Photo by R. Jowsey http://www.deerticks.com/content/modules/rhino.pages/files/uploads/deer/deer-ticks/img-002.jpg

Everything Is Connected: Example Wild mice carry the organism that causes Lyme disease. Ticks can pick up the organism when they bite mice. Then the ticks can bite and infect humans. http://ladydamorea.files.wordpress.com/2012/06/deertickbullseye.jpg

Everything Is Connected: Example This example shows that in nature, things that we would never think were connected—mice, acorns, ticks, and humans—can be linked to each other in a complex web http://www.thefastertimes.com/globalpandemics/files/2010/01/borrelia-burgdoferi-life-cycle.gif

Defining an Ecosystem The mice, deer, moths, oak trees, and ticks in the previous example are all part of the same ecosystem. An ecosystem is all of the organisms (biotic) living in an area together with their physical (abiotic) environment.

Defining an Ecosystem Ecosystems can be large like an oak forest or coral reef, or they can be small like the vacant lot next door to your home. The Natick projects. http://www.biology-blog.com/images/blogs/12-2006/oak-forest-5720.jpg http://www.nexuslearning.net/books/Holt_Env_Science/4-1.pdf

Defining an Ecosystem Just like living things are connected, so to are ecosystems. Things move from one ecosystem into another. Soil washes from a mountain into a lake, birds migrate from Michigan to Mexico, and pollen blows from a forest into a field.

The Components of an Ecosystem In order to survive, ecosystems need at least five basic components: A source of energy Mineral nutrients Water Oxygen Living organisms Photo by R. Jowsey

Biotic and Abiotic Factors An ecosystem is made up of both living and nonliving things. Biotic factors are the living and once living parts of an ecosystem, including all of the plants and animals. The biotic parts of an ecosystem interact with each other in various ways (food webs, symbiosis, etc).

Biotic and Abiotic Factors While living things interact with each other in an ecosystem, they also interact with the non-living factors in an ecosystem. The non-living components of an ecosystem are known as abiotic factors.

Biotic and Abiotic Factors Identify three biotic and three abiotic factors that are in the cold northern ecosystem of Denali National Park in Alaska (shown in photo). http://www.nexuslearning.net/books/Holt_Env_Science/4-1.pdf

Biotic Factors 1. 2. 3.

Abiotic Factors 1. 2. 3.

Organisms An organism is an individual living thing. You are an organism, as is an ant crawling across the floor, an ivy plant on the windowsill, and a bacterium in your intestines. Organisms are classified into 4 major groups: Bacteria, Plants, Protists, and Animals. Period 1 Organism Peter Creed

Species A species is a group of organisms that are closely related. In order for two organisms to be classified into the same species, they must meet thesefour criteria. The two organisms must able to: Successfully mate in a Natural Environment (not a lab or zoo, etc.) and produce viable offspring (healthy, able to survive to adulthood) and those offspring are fertile (can reproduce). All humans, for example, are members of the species group sapiens and the genus group Homo. This produces the scientific name for humans; Homo sapien.

Species The photo shows a zedonk. A zedonk is a cross between a zebra and a donkey. The zedonk is a sterile animal and cannot reproduce. Therefore, a zebra and a donkey are NOT the same species. http://i.cdn.turner.com/cnn/2010/US/09/23/what.is.zedonk/story.zedonk.carr.jpg

Species Zebras and donkeys can successfully mate, in a natural environment and produce viable offspring. Are zebras and donkeys therefore members of the same species? Why or why not? http://www.greatplay.net/images/zebra.jpg http://upload.wikimedia.org/wikipedia/commons/thumb/7/7b/Donkey_1_arp_750px.jpg/250px-Donkey_1_arp_750px.jpg http://i.cdn.turner.com/cnn/2010/US/09/23/what.is.zedonk/story.zedonk.carr.jpg

Populations A population is all the members of the same species that live in the same place at the same time. An important characteristic of a population is that its members usually breed with one another rather than with members of other populations. Populations have really cool names: pod of bottlenose dolphins, gaggle of Canadian geese, murder of crows, smath of jellyfish. http://en.wikipedia.org/wiki/List_of_animal_names

Populations The Bison will usually mate with another member of the same herd, just as the wildflowers will usually be pollinated by other flowers in the same field. http://www.nexuslearning.net/books/Holt_Env_Science/4-1.pdf

Communities An organism does not live alone and neither does a population. A community is a group of various species that live in the same place and interact with each other.

Communities A pond community, for example, includes all of the populations of plants, fish, and insects that live in and around the pond. All of the living things in an ecosystem are members of the same community. Photo by R. Jowsey

Communities The most obvious difference between communities is the types of species they have. Land communities are often dominated by a few species of plants. In turn, these plants determine what other organisms live in that community.

Communities For example, the most obvious feature of a Colorado forest might be its ponderosa pine trees. This pine community will have animals, such as squirrels, that live in and feed on these trees. http://www.sprucepointtreefarm.com/images/spruce.jpg http://shelledy.mesa.k12.co.us/staff/computerlab/images/CO_Mammals_Pine_squirrel.jpg

Habitat The squirrel discussed above lives in a pine forest. The pine forest is the squirrel’s habitat. A habitat is where an organism lives. The habitat of the salamander in this photo is a damp forest floor. http://www.nexuslearning.net/books/Holt_Env_Science/4-1.pdf

Habitat Every habitat has specific characteristics that the organisms that live there need to survive. A coral reef contains sea water, coral, sunlight, and a wide variety of other organisms. If any of these factors change, then the habitat changes because everything is connected. http://www.coralreefinfo.com/images/coral_reef.jpg

Niche An organism’s niche is the role it plays in an ecosystem. Often describes where an organism “fits” in a food chain. Example: A woodpecker’s niche is eating insects

Chapter 7: Aquatic Ecosystems. Environmental Science and the Earth How Ecosystems Work Chapter 7: Aquatic Ecosystems. Environmental Science and the Earth

Life Depends on the Sun The ultimate source of energy for almost all living things is the sun. Energy from the sun enters an ecosystem when a plant uses sunlight to make sugar molecules in a process called photosynthesis. http://thundafunda.com/DESKTOPS/plog-content/thumbs/nature/orange-sun-sky/small/533-dewy-meadow-sunrise--oakland-county--michigan---.jpg

Photosynthesis Plants, algae, and some bacteria capture solar energy and use it to drive a series of photo-chemical reactions that convert carbon dioxide and water into glucose and oxygen. http://www.physicalgeography.net/fundamentals/images/photosynthesis.jpg

Photosynthesis When an animal eats a plant, some energy is transferred from the plant to the animal. This energy is used to move, grow, and reproduce. Photo by R.L. Jowsey

The Chemical Equation for Photosynthesis Sunlight 6 CO2 6 H2O C6H12O6 6 O2 Carbon Dioxide + Water -------------------------------- Sugar + Oxygen

Autotrophs are Producers Plants and other organisms that undergo photosynthesis are known as Autotrophs. Autotrophs have cells with chloroplasts (tiny organelles within the cell) which are the site of photosynthesis. The green pigment chlorophyll is responsible for photosynthesis.

Transfer of Energy When a rabbit eats a clover plant, the rabbit gets energy from the carbohydrates (glucose) the clover plant made through photosynthesis. http://1.bp.blogspot.com/_fBOxZ22TEZ8/S6CCNVURHTI/AAAAAAAAACY/B_HbP71gkYk/s400/Quietland+Bunny+eating+clover.jpg

Transfer of Energy When a coyote eats a rabbit, some of the energy is transferred from the rabbit to the coyote. Rabbits and Coyotes are heterotrophs – also called consumers. http://www.nationalgeographicstock.com/comp/MI/001/1241723.jpg

What Eats What? What Eats What in an Ecosystem Energy Source Examples Producer Makes its own food through photosynthesis or chemical sources Grasses, ferns, flowering plants, trees, some bacteria Consumer Gets energy by eating producers and other consumers Mice, starfish, elephants, turtles, humans, and ants

Types of Consumers in an Ecosystem Herbivores – eat autotrophs (producers). Carnivores – eat other heterotrophs (consumers). http://1.bp.blogspot.com/_fBOxZ22TEZ8/S6CCNVURHTI/AAAAAAAAACY/B_HbP71gkYk/s400/Quietland+Bunny+eating+clover.jpg Photo by R.L. Jowsey

Types of Consumers in an Ecosystem (cont) Omnivore – eat both producers and consumers. Decomposer – breaks down dead organisms in an ecosystem and returns nutrients to the soil, water, and air. Photo by R.L. Jowsey http://www.ucmp.berkeley.edu/fungi/basidio/mushroomsismall.jpg

Types of Consumers in an Ecosystem Photo by R.L. Jowsey

Energy Transfer Each time an organism eats another organism, a transfer of energy occurs. We can trace the flow of energy as it travels through an ecosystem by studying food chains, food webs, and trophic levels.

Food Chains and Food Webs A food chain follows the flow of energy from one organism to the next as each organism eats another organism. http://www.sheppardsoftware.com

Food Chains and Food Webs A food web includes multiple food chains interconnected within an ecosystem. http://www.biologycorner.com/resources/foodweb01.gif

Trophic Levels Each step through which energy is transferred in a food chain is known as a trophic level. http://images.tutorvista.com/content/environment/trophic-levels-food-chain.jpeg

Trophic Levels Each time energy flows into the next trophic level, some is lost and less energy is available to the next trophic level. Only about 10% of energy transferred is available to the next trophic level. http://images.tutorvista.com/content/environment/trophic-levels-food-chain.jpeg

Trophic Levels and Energy Pyramid Energy Pyramids One way to visualize the loss of energy at each trophic level is to draw an energy pyramid. Trophic Levels and Energy Pyramid http://www.etap.org/demo/biology_files/lesson6/kep26.jpg