Ecosystems Ecosystems are complex, interactive systems that include both living (biotic) and non-living (abiotic) components of the environment. Populations of organisms are dependent on their interactions with both the biotic and abiotic factors that make up the environment. All the different ecosystems on Earth make up the Biosphere.

Ecosystems Ecosystems have a structure that groups the organisms in an order of least complex to most complex. 1. Individual organisms (species=organisms interbreed an produce fertile offspring) 2. Populations 3. Communities 4. Ecosystems 5. Biosphere

Ecosystems Populations are species that live an interact in a particular area. There are several ways to measure the numbers of species in a population: 1. Density dependent factors- these are limiting factors that affect large population more than small ones. They include competition (for food, water, shelter, and space), predation, parasitism, and disease. The larger the population the more these factors affect the numbers and health of the population.

Ecosystems 2. Density independent factors- are factors that occur regardless of how large or small the population. They are mostly abiotic; weather changes, natural pollution, natural disasters. 3. Abiotic and Biotic factors- affect population size and balance abiotic- water, shelter, oxygen, food, temperature, amount of sunlight, and precipitation. biotic- bacteria, fungi, plants, and animals.

Ecosystems Carrying Capacity- Is the largest population of organisms that an area can support with food, water, and shelter.

Ecosystems The interactions of more than one population form communities (all the organisms that live in a given area and the abiotic factors such as water, soil, air, and climate) and several communities interaction with each other form ecosystems, and all the ecosystems on Earth form the Biosphere.

Ecosystems Organisms in an ecosystem constantly interact with each other an these actions tend to 1.Generate stability within the ecosystem 2.Facilitate growth or restrain growth 3.Maintain the balance of resources and who uses or consumes them 4.Change both the abiotic and biotic characteristics of the environment

Symbiosis Symbiosis means two or more species live together in a close long term association. Cooperation is the hallmark relationship seen in any symbiotic relationship. There are three types of symbiotic relationships- parasitism, mutualism, and commensalism.

Predation Predation is the interaction between predator and prey. When prey is plentiful the population of the predator increases and when small the predator population decreases. There is a constant balancing of prey and predator.

Competition Competition is the relationship that occurs when two or more organisms need the same resources at the same time. Competition usually results in a decrease in population of the organism less adapted to compete for the particular resource.

Commensalism Commensalism is the interaction between two species where one benefits from the association and the other is neither benefitted or helped

Parasitism Parasitism is a relationship where one organism benefits at the expense of the other organism. Examples are tape worms, bacteria, ticks, fleas, mistletoe. Parasitism must be kept in balance or the parasite puts its own existence in jeopardy. The organism that a parasite lives on or in is called a host.

Mutualism Mutualism is the relationship where both organism benefit. Example bacteria in our intestinal tract, bird on cows back, bird in crocodile's mouth. Working together they both have a better opportunity to survive.

Commensalism A relationship where one organism benefits and the other is neither helped or harmed

The ultimate source for all energy on earth with the exception of hydrothermal vents (chemosynthesis) is the sun through photosynthesis. 6CO 2 + 6H 2 O + sunlight = C 6 H 12 O 6 + 6O 2 + ATP

Energy Pyramids Energy pyramids show how energy flows from one trophic level to the next trophic level. There are normally no more than 4 trophic levels because the energy runs out. Decomposers at each level are responsible for recycling the dead materials back in to the soil.

Energy Pyramids

Food Chain Food chain is a diagram that shows how energy flows from one organism to the next. Usually no more than 4 tropic levels because the energy runs out, (producers, primary consumers, secondary consumers, tertiary consumers, and decomposers at each level). Can be either terrestrial or aquatic or a combination of both.

Food Chain Bottom At the very bottom of the food chain are the producers. They include plant, algae, and phytoplankton. They use sunlight to make their own energy through photosynthesis ( autotrophs ). They in turn are eaten by other organisms for food energy ( heterotrophs ). The matter is transferred from one organism to the next repeatedly and finally back to the physical environment. Total matter remains constant, cannot create or destroy matter but can change its form and location.

Energy Trophic Levels 1 st Producers- Make energy through Photosynthesis 2 nd Primary Consumers- Herbivores 3 rd Secondary Consumers- Carnivores 4 th Tertiary Consumers- Omnivores

Energy transfer Only 10% of the energy transfers from one trophic level to the next. 90% is lost due to heat requirements of metabolism of the organism in that trophic level. This is why there are so few trophic levels in nature; The energy runs out.

Energy Levels Heterotroph - Cannot make its own energy. Must eat something to obtain energy. Autotroph- obtains its energy from sunlight through the process of photosynthesis. Detritivores - obtains their energy from eating dead organisms and returning nutrients to the soil.

Food Web Food web is a diagram that shows the feeding relationships in an ecosystem. Arrows in a food web point in the direction showing where the energy flows to (organism eaten starts the arrow and the eater ends the arrow). Two food webs: Terrestrial and Aquatic Humans are the top consumers in both food webs.

Food Web

Pyramid Types Energy Pyramid- shows the transfer of energy through trophic levels. Number pyramid- the bottom is the number of producers for this trophic level and counts the number of organisms in each trophic level. Numbers of organism decrease up the pyramid. Biomass Pyramid- measures the organic matter at each trophic level.

Types of Communities Marine or Aquatic- shallow ocean, open ocean, deep ocean Fresh water- swamps, lakes, bogs, rivers Terrestrial- seven different types

Aquatic Communities Shallow Ocean- Most of the ocean creature can be found here. Sunlit waters usually no more than 300 meters deep. Filled with sea creature and plants. Plankton floats freely on the surface.

Aquatic Communities Open Ocean- generally begins at the start of the continental slope. Water temperature and sunlight decrease really fast. Giant Sea Urchins, Whales, and Sharks. Plankton floats freely on the surface.

Aquatic Communities Deep Ocean- Extreme pressures, very low temperature, and no sunlight. The life that exist here are normally found around hydrothermal vents and get their energy through Chemosynthesis.

Terrestrial Communities 1. Tropical Rain Forest- 80”-180” rain per year. Large variety of species, probably ½ of all Earth’s species live here. Rather infertile soil (rain washes most of the minerals away). Most of the nutrients of the rain forest are in the plants.

Terrestrial Communities 2. Savannas- Dry tropical grasslands. 35”-60” of rain per year. Widely sparse trees. Large herds of grazing animals and predators.

Terrestrial Communities 3. Deserts- Arid lands, less than 10 “ of rain per year. Vegetation very sparse. Mostly found in Africa (Sahara), Asia, and Australia. Common plant is the cactus.

Terrestrial Communities 4. Temperate Grasslands- Seas of Grass- Highly productive soil, prairie land, deep grass roots to hold the soil and absorb water. Mostly North America, Central Eurasia, and South America. Bison or Buffalo

Terrestrial Communities Temperate Deciduous Forest- Rich Hardwoods- Plenty of rain 30”-100” rain per year. Warm long summers, and cold winters. Eastern USA, Southeastern Canada, Europe, and Western Asia. Animals are deer, bear, squirrels, beavers. Beech, Hickory, and Oak trees are plentiful.

Terrestrial Communities 6. Taiga Forest- Great Conifer Forest of the North- Cold, wet, long snowy winters. Most of rain in the summer. Leached out soil. Lots of marsh land, lakes, huge forest of spruce and fir trees. Mostly Eurasia and North America. Deer, elk, moose, wolves, and bears are common.

Terrestrial Communities 7. Tundra- Cold Plains of the Far North- Few trees and covers 20% of Earth’s surface. 10” of rain or less per year. Water that falls is usually frozen. Land is boggy permafrost