Unit 5: Ecosystems and Population Change

Comprehensive vocabulary flashcards covering Alberta ecosystems, population dynamics, taxonomy, and evolutionary theories as outlined in the lecture notes.

Taiga

Also called the Boreal Forest or 'Spruce Moose' ecosystem, it is dominated by conifers like pine and spruce that have needles to reduce water loss.

Muskeg

An ecosystem found in the northern Taiga characterized by permafrost, acidic soil, and peat formed from decomposing organic matter.

Deciduous Forest

A forest ecosystem dominated by leaf-losing trees like aspen poplar and birch, featuring rich, fertile soil and high biodiversity due to multiple layers like the canopy and understory.

Grassland

An ecosystem in southern Alberta with nutrient-rich soil and a large biomass for decomposition, often used for agriculture but possessing limited biodiversity.

Interspecific Competition

Competition for limited resources, such as food or space, between individuals of different species.

Intraspecific Competition

Competition for limited resources between organisms of the same species.

Primary Succession

A type of ecological succession that begins in an area where there is no existing community.

Secondary Succession

Ecological succession occurring in an existing community that has been partially destroyed by events like fire, logging, or farming.

Littoral Zone

The most productive part of a lake, extending from the lakeshore to where plants are no longer rooted in the bottom.

Limnetic Zone

The area of open water in a lake where there is still enough sunlight for photosynthesis, dominated by plankton.

Profundal Zone

The deepest part of a lake where no sunlight penetrates, characterized by low oxygen levels and nutrients sourced from detritus.

Benthic Zone

The lowest ecological zone in water, extending from the shoreline to the lowest part of the lake floor.

Oligotrophic Lake

A lake that is cold, deep, clear, oxygen-rich, but nutrient-poor with very few producers and consumers.

Eutrophic Lake

A lake that is warm, shallow, murky, oxygen-poor, and nutrient-rich with a high density of organisms.

Biological $O_2$ Demand (BOD)

A measure of the amount of oxygen required by decomposers; higher numbers of decomposers lead to a greater BOD and less oxygen for fish.

Biotic Potential

The maximum number of offspring a species can produce if resources are unlimited, regulated by birth potential, capacity for survival, and length of reproductive life.

Density Independent Limiting Factors

Abiotic factors, such as fire, floods, or drought, that decrease a population regardless of its size.

Density Dependent Limiting Factors

Biotic factors, such as disease, predation, and competition, that decrease a population as a result of its size.

Carrying Capacity

The maximum number of individuals of a species that an ecosystem can support, determined by limiting factors.

Taxonomy

The science of classification according to inferred relationships among organisms to identify them and recognize natural groupings.

Binomial Nomenclature

A naming system developed by Linnaeus using two parts: a capitalized Genus and a lowercase species name.

Phylogeny

The history of the evolution of a species or a group of organisms.

Dichotomous Key

A tool used to identify organisms through a repeated series of two choices, with each choice leading to a new branch.

Absolute Dating

A technique used to determine the age of a rock or fossil by measuring the rate of decay of radioactive isotopes.

Homologous Structures

Body structures that share a similar origin in tissue but have evolved different functions in different species.

Analogous Structures

Structures that are similar in function and appearance but have different evolutionary origins, such as the wings of insects and birds.

Vestigial Features

Rudimentary structures that had a useful function in an ancestor but no longer serve a purpose in the modern organism.

Inheritance of Acquired Characteristics

Lamarck's theory suggesting that organisms change because of an inner 'need' and pass on traits acquired through use or disuse to their offspring.

Natural Selection

Darwin's theory that organisms best suited for their environment are more likely to survive and reproduce, passing on beneficial variations.

Adaptive Radiation

The rapid increase in the number of species with a common ancestor, characterized by morphological and ecological diversity.

Allopatric Speciation

The formation of new species occurring when a population becomes physically separated by a geographic barrier.

Theory of Gradualism

The idea that changes to species occur at a slow and steady pace over long periods of time.

Theory of Punctuated Equilibrium

The idea that species undergo long periods of stability followed by rapid bursts of evolutionary change and speciation.