| A | B |
|---|
| Community | All the organisms that inhabit a particular area; an assemblage of populations of different species living close enough together for potential interaction. |
| Interspecific Interactions | A relationship between individuals of two or more species in a community. |
| Interspecific Competition | Competition for resources between individuals of two or more species when resources are in short supply. |
| Competitive Exclusion | The concept that when populations of two similar species complete for the same limited resources, one population will use the resources more efficiently and have a reproductive advantage that will eventually lead to the elimination of other population. |
| Ecological Niche | The sum of a species' use of the biotic and abiotic resources in its environment. |
| Resource Partitioning | The division of environmental resources by coexisting species such that the niche of each species differs by one or more significant factors from the niches of all coexisting species. |
| Ecological Niche | The sum of species' use of biotic and abiotic resources in its environment. |
| Character Displacement | The tendency for characteristics to be more divergent in sympatric populations of two species than in allopatric populations of the same two species. |
| Predation | An interactions between species in which one species, the predator, eats the other, the prey. |
| Cryptic Coloration | Camouflage that makes a potential prey difficult to spot against its background |
| Aposematic Coloration | The bright warning coloration of many animals with effective physical or chemical defenses. |
| Batesian Mimicry | A type of mimicry in which a harmless species looks like a species that is poisonous or otherwise harmful to predators. |
| Mulllerian Mimicry | Reciprocal mimicry by two unpalatable species. |
| Herbivory | An interaction in which an organism eats parts of a plant or alga. |
| Symbiosis | An ecological relationship between organisms of two different species that live together in direct and intimate contact. |
| Parasitism | A symbiotic relationship in which one organism, the parasite, benefits at the expense of another, the host, by living either within or on the host. |
| Parasite | An organism that feeds on the cell contents, tissues, or body fluids of another species (The host) while in or on the host organism. Parasites harm but usually do not kill their host. |
| Host | The larger participant in symbiotic relationship, often providing a home and foodsource for the smaller symbiont. |
| Endoparasite | A parasite that lives within a host. |
| Ectoparasite | A parasite that feeds on the external surface of a host. |
| Mutualism | A symbiotic relationship in which both participants benefit. |
| Commensalism | A symbiotic relationship in which one organism benefits but the other is neither helped nor harmed. |
| Facilitation | An interaction in which one species has a positive effect on the survival and reproduction of another species without the intimate association of a symbiosis. |
| Species Diversity | The number and relative abundance of species in a biological community. |
| Species Richness | The number of species in a biological community. |
| Relative Abundance | The proportional abundance of different species in a community. |
| Shanon Diversity | An index of community diversity symbolized by H and represented by the equation H = ō(pA ln pA + pB ln pB + pC ln pC + . . .), where A, B, C . . . are species, p is the relative abundance of each species, and ln is the natural logarithm. |
| Invasive Species | A species, often introduced by humans, that takes hold outside its native range. |
| Trophic Structure | the different feeding relationships in an ecosystem, which determine the route of energy flow and the pattern of chemical cycling. |
| Food Chain | The pathway along which food energy is transferred from trophic level to trophic level, beginning with producers. |
| Food Webs | The interconnected feeding relationships in an ecosystem. |
| Energetic Hypothesis | The concept that the length of a food chain is limited by the inefficiency of energy transfer along the chain. |
| Dynamic Stability Hypothesis | The concept that long food chains are less stable than short chains. |
| Biomass | The total mass of organic matter comprising a group of organisms in a particular habitat. |
| Dominant Species | A species with substantially higher abundance or biomass than other species in a community. Dominant species exert a powerful control over the occurrence and distribution of other species. |
| Keystone Species | A species that is not necessarily abundant in a community yet exerts strong control on community structure by the nature of its ecological role or niche. |
| Ecosystem Engineers | An organism that influences community structure by causing physical changes in the environment. |
| Bottom-up Model | A model of community organization in which mineral nutrients influence community organization by controlling plant or phytoplankton numbers, which in turn control herbivore numbers, which in turn control predator numbers. |
| Top-down Model | A model of community organization in which predation influences community organization by controlling herbivore numbers, which in turn control plant or phytoplankton numbers, which in turn control nutrient levels; also called the trophic cascade model. |
| Biomanipulation | An approach that applies the top-down model of community organization to alter ecosystem characteristics. For example, ecologists can prevent algal blooms and eutrophication by altering the density of higher-level consumers in lakes instead of by using chemical treatments. |
| Disturbance | A natural or human-caused event that changes a biological community and usually removes organisms from it. Disturbances, such as fires and storms, play a pivotal role in structuring many communities. |
| Nonequilibrium Model | A model that maintains that communities change constantly after being buffeted by disturbances. |
| Ecological Succession | Transition in the species composition of a community following a disturbance; establishment of a community inan area virtually barren of life. |
| Primary Succession | A type of ecological succession that occurs in an area where there were originally no organisms present and where soil has not yet formed. |
| Secondary Succession | A type of succession that occurs where an existing community has been cleared by some disturbance that leaves the soil or substrate intact. |
| Evapotranspiration | The total evaporation of water from an ecosystem, including water transpired by plants and evaporated from a landscape, usually measured in millimeters and estimated for a year. |
| Species Area-Curve | The biodiversity pattern that shows that the larger the geographic area of a community is, the more species it has. |
| Zoonotic Pathogens | A disease-causing agent that is transmitted to humans from other animals. |
| Vector | An organism that transmits pathogens from one host to another. |
| What's an example of Interspecific Competition? | Weed and Garden plants competing for nutrients. |
| Can 2 species who's ecological niche are identical Coexist? | No because it would result to Competitive Exclusion. |
| Whats an example of Resource Partitioning? | 7 different species of lizard in one area able to live with each other. |
| What does the Energy Hypothesis predict? | Food chains should be relatively longer in habitats of higher photosynthetic production. |
| What doe the Dynamic Stability Predict? | Food chains should be shorter in unpredictable environments. |
| Why does Dynamic Stability propose long food chains are less stable than short ones? | Population flunctuation at lower trophic levels are maginified at higher levels potentially causing the local extinction of top predators. |
