Term
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Definition
| Occurs when high levels of nitrogen and phosphorous cause algal blooms. Algal blooms result in a large accumulation of dead organic matter which leaders to high biochemical demand for oxygen as decomposers use up oxygen to break down the detritus. |
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Term
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Definition
| states that biodiversity provides insurance in the face of environmental change. Specifically, it predicts that high diversity systems will be more resistant and resilient in their various ecosystem functions (e.g. production, decomposition) despite changing environmental conditions. |
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Term
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Definition
| Resilience refers to an ecosystem's ability to return to a given state following a perturbation as well as an ecosystem's ability to resist changing states when perturbed. |
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Term
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Definition
| the sequential replacement of species at a site over time |
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Term
| Three major drivers in biodiversity loss |
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Definition
Habitat loss (number one)
Overexploitation
Non-native invasions
Pollution (aquatic systems) Ok..I realize that's four not three |
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Term
| net primary production (NPP) |
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Definition
| The amount of energy (per unit time) that autotrophs capture by photosynthesis and chemosynthesis, minus the amount they use in cellular respiration. |
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Term
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Definition
| The zone of rapid temperature change in a lake beneath the epilimnion and above the hypolimnion. |
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Term
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Definition
| Freshly dead or partially decomposed remains of organisms. |
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Term
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Definition
| The scientific study of phenomena that affect the maintenance, loss, and restoration of biodiversity. |
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Definition
| An introduced species that survives and reproduces in its new environment, sustains a growing population, and has large effects on the native community. |
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Term
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Definition
| A process by which certain bacteria convert nitrate (NO3–) into nitrogen gas (N2) and nitrous oxide (N2O) under hypoxic conditions. |
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Term
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Definition
| Nutrient-rich; characterized by high primary productivity. |
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Term
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Definition
| The vertical movement of dissolved matter and fine mineral particles from upper to lower layers of soil. |
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Term
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Definition
| A process by which certain chemoautotrophic bacteria, known as nitrifying bacteria, convert ammonia (NH3) and ammonium (NH4+) into nitrate (NO3–) under aerobic conditions. |
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Term
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Definition
| The process of taking up nitrogen gas (N2) and converting it into chemical forms that are more chemically available to organisms. |
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Term
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Definition
| The cyclic movement of nutrients between organisms and the physical environment. |
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Term
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Definition
| A process by which soluble phosphorus combines with iron, calcium, and aluminum to form insoluble compounds (secondary minerals) that are unavailable to organisms as nutrients. |
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Term
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Definition
| A progressive increase in the concentration of a substance in an organism's body over its lifetime. |
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Term
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Definition
| The proportion of the biomass available in an ecosystem that is ingested. |
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Term
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Definition
| A diagram showing the connections between organisms and the food they consume. |
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Term
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Definition
| The proportion of assimilated food that is used to produce new consumer biomass. |
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Term
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Definition
| A change in the rate of consumption at one trophic level that results in a series of changes in species abundance or composition at lower trophic levels. |
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Term
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Definition
| A measure of the transfer of energy between trophic levels, consisting of the amount of energy at one trophic level divided by the amount of energy at the trophic level immediately below it. |
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Term
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Definition
| A group of species that obtain energy in similar ways, classified by the number of feeding steps by which the group is removed from primary producers, which are the first trophic level. |
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Term
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Definition
| A common approach to conceptualizing trophic relationships in an ecosystem in which a stack of rectangles is constructed, each of which represents the amount of energy or biomass within one trophic level. |
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Term
| gross primary production (GPP) |
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Definition
| The amount of energy that autotrophs capture by photosynthesis and chemosynthesis per unit time. |
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Term
| net primary production (NPP) |
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Definition
| The amount of energy (per unit time) that autotrophs capture by photosynthesis and chemosynthesis, minus the amount they use in cellular respiration |
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Term
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Definition
| The balance between heterotroph energy gains through ingestion and heterotroph energy losses by cellular respiration and egestion. |
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Term
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Definition
| The rate that chemical energy in an ecosystem is generated by autotrophs, derived from the fixation of carbon during photosynthesis and chemosynthesis. |
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Term
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Definition
| Energy in an ecosystem that is derived from the consumption of organic compounds produced by other organisms. |
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Term
| complementarity hypothesis |
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Definition
| A hypothesis proposing that the strengths of the effects of species' ecological functions on their communities vary dramatically, such that "driver" species have a large effect on community function, while "passenger" species have a minimal effect. |
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Term
| dynamic equilibrium model |
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Definition
| An elaboration of the intermediate disturbance hypothesis proposing that species diversity is maximized when the level of disturbance and the rate of competitive displacement are roughly equivalent. |
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Term
| intermediate disturbance hypothesis |
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Definition
| A hypothesis proposing that species diversity in communities should be greatest at intermediate levels of disturbance (or stress or predation) because competitive exclusion at low levels of disturbance and mortality at high levels of disturbance should reduce species diversity. |
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Term
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Definition
| The use of limiting resources by different species in a community in different ways. |
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Term
| resource ratio hypothesis |
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Definition
| A hypothesis proposing that species can coexist in a community by using the same resources, but in differing proportions. |
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Term
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Definition
| The tendency of a community to remain the same in structure and function. |
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Term
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Definition
| The study of variation in species composition and diversity among geographic locations. |
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Term
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Definition
| Occurring in a particular geographic location and nowhere else on Earth. |
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Term
| equilibrium theory of island biogeography |
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Definition
| A theory proposing that the number of species on an island or in an island-like habitat results from a dynamic balance between immigration rates and extinction rates. |
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Term
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Definition
| A spatial scale that is essentially equivalent to a community. |
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Term
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Definition
| A spatial scale that encompasses a geographic area where the climate is roughly uniform and the species contained therein are often restricted to that region by dispersal limitation. |
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Term
| species–area relationship |
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Definition
| The relationship between species richness and area sampled. |
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Term
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Definition
| An abiotic event that kills or damages some individuals and thereby creates opportunities for other individuals to grow and reproduce. |
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Term
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Definition
| The inability of a community that has undergone change to shift back to the original community type, even when the original conditions are restored. |
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Term
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Definition
| Succession that involves the colonization of habitats devoid of life |
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Term
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Definition
| Succession that involves the reestablishment of a community in which some, but not all, of the organisms have been destroyed |
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Term
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Definition
| The process of change in the species composition of a community over time as a result of abiotic and biotic agents of change. |
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Term
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Definition
| A group of interacting species that occur together at the same place and time. |
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Term
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Definition
| Interactions between two species, including competition, exploitation, and positive interactions. |
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Term
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Definition
| A species that has large, community-wide effects by virtue of its size or abundance, its strong competitive ability, or its provision of habitat or food for other species, also called a foundation species. |
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Term
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Definition
| Non-trophic interactions, such as competition and some positive interactions, that occur within a trophic level. |
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Term
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Definition
| Interactions in which the relationship between two species is mediated by a third (or more) species. |
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Term
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Definition
| A strong interactor that has an effect on energy flow and community structure that is disproportionate to its abundance or biomass. |
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Term
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Definition
| The index most commonly used to describe species diversity quantitatively. |
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Term
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Definition
| A measure that combines the number of species (species richness) in a community and their relative abundances compared with one another (species evenness). |
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Term
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Definition
| The relative abundances of species in a community compared with one another. |
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Term
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Definition
| The number of species in a community. |
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Term
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Definition
| A change in the rate of consumption at one trophic level that results in a series of changes in species abundance or composition at lower trophic levels. |
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Term
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Definition
| A group of species that obtain energy in similar ways, classified by the number of feeding steps by which the group is removed from primary producers, which are the first trophic level. |
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Term
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Definition
| In a mutualism, an individual that increases its production of offspring by overexploiting its mutualistic partner. |
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Term
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Definition
| An interaction between two species in which individuals of one species benefit while individuals of the other species do not benefit and are not harmed. |
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Term
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Definition
| A mutually beneficial interaction between individuals of two species (a +/+ relationship). |
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Term
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Definition
| A relationship in which two species live in close physiological contact with each other. |
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Term
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Definition
| An organism on or within which a parasite or other symbiont lives. |
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Term
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Definition
| Relatively large parasite species, such as arthropods and worms |
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Term
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Definition
| Parasite species too small to be seen with the naked eye, such as bacteria, protists, and fungi |
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Term
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Definition
| An organism that lives in or on an organism of another species, referred to as its host; a symbiont is the smaller member of a symbiosis |
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Term
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Definition
| The minimum number of individuals susceptible to a disease that must be present in a population for the disease to become established and spread |
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Term
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Definition
| A defense against predators in which prey species resemble less palatable organisms or physical features of their environment, causing potential predators to mistake them for something less desirable to eat. |
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Term
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Definition
| A process in which competition causes the phenotypes of competing species to evolve to become more different over time, thereby causing the species to become more different where they live together than where they live apart. |
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Term
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Definition
| A constant used in the Lotka–Volterra competition model to describe the extent to which an individual of one competing species decreases the per capita growth rate of the other species. |
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Term
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Definition
| An interaction between individuals of two species in which each is harmed by their shared use of a resource that limits their ability to grow, survive, or reproduce (a –/– relationship). |
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Term
| competitive exclusion principle |
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Definition
| The principle that two species that use a limiting resource in the same way cannot coexist indefinitely. |
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Term
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Definition
| An interaction in which species compete indirectly through their mutual effects on the availability of a shared resource |
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Term
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Definition
| An interaction in which species compete directly by performing antagonistic actions that interfere with the ability of their competitors to use a resource that both require, such as food or space |
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Term
| Lotka–Volterra competition model |
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Definition
| A modified form of the logistic equation used to model competition |
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Term
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Definition
| The use of limiting resources by different species in a community in different ways. |
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Term
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Definition
| A feature of the environment that is required for growth, survival, or reproduction and which can be consumed or otherwise used to the point of depletion. |
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Term
| zero population growth isoclines |
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Definition
| Lines derived from the Lotka–Volterra competition model marking the conditions under which a population does not increase or decrease in size. |
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Term
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Definition
| Limitation of the abundance of a population by nutrient supply or by the availability of food. |
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Term
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Definition
| A metapopulation pattern in which habitat patches located far away from occupied patches are less likely to be colonized than are nearby patches. |
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Term
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Definition
| A set of spatially isolated populations linked to one another by dispersal. |
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Term
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Definition
| Limitation of the abundance of a population by consumers |
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Term
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Definition
| The maximum population size that can be supported indefinitely by the environment, represented by the term K in the logistic equation. |
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Term
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Definition
| A life table in which the fate of a group of individuals born during the same time period (a cohort) is followed from birth to death. |
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Term
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Definition
| Of or referring to a factor that causes birth rates, death rates, or dispersal rates to change as the density of the population changes |
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Term
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Definition
| Of or referring to a factor whose effects on birth and death rates are independent of population density. |
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Term
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Definition
| The average number of offspring produced by a female while she is of age x (denoted Fx in a life table). |
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Term
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Definition
| Change in the size of a population that is rapid at first, then decreases as the population approaches the carrying capacity of its environment. |
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Term
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Definition
| A summary of how survival and reproductive rates in a population vary with the age of individuals; in species for which age is not informative or is difficult to measure, life tables may be based on the size or life history stage of individuals. |
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Term
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Definition
| A pattern of population growth in which one or more density-dependent factors increase population size when numbers are low and decrease population size when numbers are high. |
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Term
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Definition
| The proportion of individuals of age x that survive to be age x + 1 (denoted Sx in a life table). |
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Term
| type I survivorship curve |
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Definition
| A survivorship curve in which newborns, juveniles, and young adults all have high survival rates and death rates do not begin to increase greatly until old age. |
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Term
| type II survivorship curve |
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Definition
| A survivorship curve in which individuals experience a constant chance of surviving from one age to the next throughout their lives. |
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Term
| type III survivorship curve |
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Definition
| A survivorship curve in which individuals die at very high rates when they are young, but those that reach adulthood survive well later in life. |
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Term
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Definition
| A predictive tool that models the ecological niche occupied by a species based on the conditions at locations the species is known to occupy. |
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Term
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Definition
| A process of evolutionary change in which traits that confer survival or reproductive advantages tend to increase in frequency in a population over time. |
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Term
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Definition
| The transfer of alleles from one population to another via the movement of individuals or gametes. |
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Term
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Definition
| A process in which chance events determine which alleles are passed from one generation to the next, thereby causing allele frequencies to fluctuate randomly over time; the effects of genetic drift are most pronounced in small populations. |
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