ecology

Organization of Life Biosphere= planet Earth Biome= ecosystems in a particular climate. Ex. Tropical rain forest. Ecosystem= all living & nonliving things in an area at one time. Community= all living things in a particular ecosystem. Population= all living things of the same species in an ecosystem. Individual= one organism. Key Terms: Biotic= living things Abiotic= nonliving things

Key Terms Habitat= the dwelling place where an organism seeks food and shelter. Niche= the role that an organism plays in its community, such as what it eats and where it lives. Species= a group of similar organisms that can breed with one another to produce fertile offspring.

Biomes Terrestrial (on land) biomes Tundra Taiga or Coniferous Forest Deciduous Forest Grasslands Tropical Rain Forest Deserts

Biomes Aquatic Biomes Freshwater ecosystems Estuary= where fresh water and saltwater meet in a coastal area. Marine ecosystems= saltwater Intertidal zone= area of shore seen between low and high tides. Pelagic zone= largest ocean area. Benthic zone= ocean floor.

Relationships Among Organisms Symbiosis (Symbiotic Relationship)= a long-term association between 2 members of a community. 3 Types of Relationships: 1. Commensalism= 1 member benefits, the other is unaffected. Very rare in nature. 2. Mutualism= both members benefit. Ex. Sea anemone & clown fish. 3. Parasitism= 1 member benefits, the other is harmed. Ex. Flea on dog.

Relationships Among Organisms Competition= when 2 or more organisms seek the same resource that is in limited supply. * A resources may be food, water, mates, light, or space. * Competition can occur between members of the same species or different species.

Relationships Among Organisms Predation Predators= an organism that feeds on other living things (prey). Prey= the organism being eaten. Important Note: Predators typically control the population size of the prey species. Less predators= More prey.

Energy Flow Through Ecosystem Biomass= amount of biological matter in ecosystem. Energy Flow= the transfer of energy within an ecosystem

Food Chains & Food Webs Food Chain= shows the connections between organisms (Who eats what?) Food Web= shows the interactions between food chains. Decomposers= Live on dead or decaying organisms. (Ex. Fungi & Bacteria) AKA Saprophytes Producers= plants and any other autotrophs (algae in oceans) Consumers= depend on other organisms for food. AKA Heterotrophs. (They must eat) Herbivores= Eat only plants. Carnivores= Eat only other animals. Omnivores= Eat both.

Ecological Pyramids Trophic Level= the positions occupied by an organism in a food chain.

Energy Pyramids 10% Law= the amount of energy available to organisms at a trophic level is 10% of what was at the previous level.

Energy Pyramids Number Pyramid= the number of individuals in a population.

Energy Pyramids Biomass Pyramid= the amount of mass or living tissue at each trophic level.

Populations Population= a groups of organisms of the same species living in the same area. Population dynamic= Study of the growth rate, density, and distribution of a population. Growth Rate= the change in population size over a period of time. Immigration= organisms move INTO a population. Emigration= organisms move OUT of a population.

Populations Exponential Growth= occurs when population growth starts out slowly and then increases rapidly as the number of reproducing individuals increase. AKA J- shaped curve.

Populations Logistic Growth= Shows when a population has reached its carrying capacity. AKA S-shaped curve Carrying Capacity= The # of individuals the environment can support in a given area.

Populations Limiting Factor= anything in a population that limits population growth. Ex. Food, space, water, disease. Density-dependent factors= depends on # of individuals in population. Ex. Competition, disease, predation. Density-independent factors= does NOT matter how many individuals are in population. Ex. Natural disasters, weather, seasonal cycles.

Succession Ecological Succession= the changes an ecosystem goes through over time. Primary Succession= occurs on rock (barren land). Ex. On newly formed volcanic rock. Pioneer Species= The first species to grow on barren land. Secondary Succession= occurs where soil is already present. Ex. After forest fire, other natural disaster, or logging. Climax Community= a mature relatively stable community where there is little change in the predominant species in an area.

Primary Succession

Secondary Succession

Humans & the Environment Positive Human Actions Recycling Using renewable resources, instead on nonrenewable ones. Negative Human Actions Pollution= can occur in the air, soil, and water. Pesticides= chemical agents used to kill organisms, usually animals. Habitat Reduction= destroying habitats of organisms Urbanization= creating cities and suburbs, which disturbs the natural land. *Agriculture is the main cause of habitat destruction.

Biodiversity Biodiversity= measure of variety of organisms in an area. The more biodiversity, the better. Pollution, habitat destruction, etc. can lead to a loss of biodiversity. Biodiversity is often used to measure the overall health of an ecosystem.

Species Interaction Endangered or Threatened Species= means that very few of those organisms are alive. These organisms may be put on Endangered Species List so that they are protected. Non-native (Invasive) Species= foreign organism that enter ecosystems, usually through human action. Ex. Kudzu, jumping carp.

Loss of Genetic Diversity Genetic diversity is a result of sexual reproduction. Loss of genetic diversity may result from cloning or asexual reproduction. This is a problem with monoculture farms that have large quantities of identical organisms.

Global Warming Global Warming= describes the measured rise in the Earth’s atmospheric and oceanic temperatures. Greenhouse Effect= traps solar heat within the Earth’s atmosphere.

Human Consumption Natural Resources= Ex. Water, soil, and air. What humans need for survival. Humans also use a great deal of power. (Fossil fuels, which are nonrenewable.)