Principles of Ecology Chapter 2

Section 1 Vocabulary Ecology Biosphere Biotic Factor Abiotic Factor Population Biological Community Ecosystem Biome Habitat Niche Predation Symbiosis Mutualism Commensalism Parasitism

Section 1 Organisms and Their Relationships Ecology Each organism depends on both living and nonliving factors in their environment for survival Scientists who study ecology are called ecologists Science models are a way of creating a visual representation of a hypothesis to test in a lab setting

The Biosphere Biotic Factors Abiotic Factors All living things in an environment Interactions among organisms are necessary for the health of all species in the same geographic location Abiotic Factors Nonliving factors in the environment Factors may include temperature, air or water currents, sunlight, soil type, rainfall, or available nutrients Organisms depend on both abiotic and biotic factors for survival If an organism moves to another location with different abiotic factors, it must adapt or it dies

Levels of Organization Organism, Population, Biological Community, Ecosystem, Biome, Biosphere Organisms, populations, and biological communities Lowest level is the organism Individual organisms often compete for the same resources; if resources are plentiful, the population grows Usually there are factors that prevent a population from becoming extremely large Organisms may or may not compete for the same resources in a biological community

Ecosystems, biomes, and the biosphere Ecosystem is similar to a biological community, except that it also includes abiotic factors Ecosystem can be large or small and even overlap Biome is a large group of ecosystems The biosphere consists of all of the biomes; the highest level of organization on Earth

Ecosystem Interactions Interactions between organisms are important to survival in an ecosystem (ex. Tree) Habitat could be one tree or a grove of trees An organism’s niche is it’s role or job Community Interactions Competition Occurs when more than one organism uses a resource at the same time Strong directly compete with the weak Usually the strong survive; the weak could move to another location If the resource is plentiful, them competition is not very fierce

Symbiotic Relationships Predation Many species get their food by eating (predator) other species (prey) Ladybug and praying mantises are insect predators, but also called beneficial insects (used for garden control) Symbiotic Relationships Mutualism: both benefit (algae and fungi form lichens through a mutualistic behavior Commensalism: one benefits and the other gets neither hurt or helped (clownfish and sea anemones; clownfish get protected) Parasitism: one benefits at the expense of the other (ticks or fleas) In parasitism if the host dies, so can the parasite

Section 2 Vocabulary Autotroph Heterotroph Herbivore Carnivore Omnivore Detritivore Trophic Level Food Chain Food Web Biomass

Section 2 Flow of Energy in an Ecosystem Autotrophs Green plants and other organisms that produce their own food (primary producers) Are the foundations for all ecosystems because they make energy available for all organisms Heterotrophs Also called consumers Gets energy from consuming other organisms Decomposers break down dead organisms Decomposers are the primary method used to make nutrients available for producers to reuse

Models of Energy Flow Food Chains Food Webs Ecological Pyramids Arrows normally start with autotrophs and move to heterotrophs Remaining energy is released into environment and not available to organisms Food Webs Usually more complex than a food chain Food webs are the most common Ecological Pyramids Shows the relative amounts of energy, biomass, or numbers of organisms at each trophic level in an ecosystem Only 10% of all energy is transferred to level above Number of organisms at each level gets less, as you move up the energy pyramid

Food Web

Section 3 Vocabulary Matter Nutrient Biogeochemical cycle Nitrogen fixation Denitrification

Section 3 Cycling of Matter Cycles in the Biosphere Connection to Chemistry In most ecosystems, plants obtain nutrients, in the form of elements and compounds, from the air, soil, or water The Water Cycle Constant recycling Same water today that was here when Earth began Approximately 90% of water vapor evaporates from oceans, lakes, and rivers, 10% from the surfaces of plants through transpiration All living organisms rely on fresh water

Freshwater constitutes only about 3% of all water Water available to living organisms is about 31% The remaining 69% of freshwater is frozen Processes in the water cycle are evaporation, condensation, precipitation, transpiration, and percolation (seepage)

The Carbon and Oxygen Cycle All living things are composed of carbon molecules Carbon and oxygen make up the molecules essential for life Green plants convert carbon dioxide and water into carbohydrates and release oxygen back into the atmosphere (photosynthesis) Carbon dioxide is recycled when autotrophs and heterotrophs release it back into the air during cellular respiration Carbon enters a long cycle when organic matter is buried Carbon is released from fossil fuels when they are burned Carbon and oxygen can also combine with calcium to create calcium carbonate

The Carbon Cycle

The Nitrogen Cycle Largest concentration of nitrogen is found in the atmosphere Plants and animals can’t use nitrogen directly from the atmosphere; only from the soil Nitrogen can be fixed (converted) during an electrical storm Nitrogen is often a factor that limits the growth of producers Nitrogen gets returned to the soil in several ways: animals urinate, organisms die, or denitrification

Nitrogen Cycle

The Phosphorus Cycle Phosphorus is essential for the growth and development of organisms; limits the growth of producers Short term and long term cycles Producers obtain it from the soil and consumers by eating the producers When organisms die or produce wastes, decomposers return the phosphorus to the soil where it can be used again Moves from the short term to the long term through precipitation and sedimentation to form rocks In the long term cycle, erosion and weathering of rocks that contain phosphorus, adds it back to the soil

Phosphorus Cycle