Ecology Study Notes

A type of natural selection where one extreme phenotype is favored, shifting the population towards that trait. Think of giraffes with longer necks reaching higher leaves, giving them an advantage.

A type of natural selection where the average phenotype is favored, reducing variation and maintaining the status quo. Picture a bird with a medium-sized beak, best for both small and large seeds.

A type of natural selection where both extreme phenotypes are favored, leading to increased variation and potentially even speciation. Imagine a bird with either small or large beaks, specializing on different food sources.

A large geographical area with similar climate and vegetation types, determined by factors like temperature, precipitation, and soil. For instance, the tropical rainforest is a biome with high rainfall and diverse plant life.

A technique used to study animal movements by attaching a radio transmitter to the animal and tracking its signals. Researchers can monitor the animal's location and behavior over time.

A method used to sample plant or animal populations in a defined square area. It's useful for studying the distribution and abundance of organisms within a habitat.

A technique used to estimate population size by capturing, marking, and releasing a sample of animals, then capturing another sample and counting the number of marked individuals. This method is best suited for mobile animals that can be caught and released.

A method used to study changes in vegetation or animal distribution along a line or path. It allows researchers to assess environmental gradients and species diversity across a habitat.

A model of population growth that incorporates carrying capacity and shows the slowing of population growth as it approaches the limit of available resources.

The maximum population size that an environment can sustainably support, given the available resources. Imagine a lake that can only sustain a certain number of fish due to food limitations.

When two species with very similar ecological niches are placed together, one species outcompetes the other, leading to the local extinction of the weaker competitor. Think of a lion and a cheetah both hunting the same prey in an area.

A symbiotic relationship where both species benefit from the interaction. Think of a bee pollinating a flower, getting food while helping the flower reproduce.

A type of mutualistic relationship where the species involved are completely dependent on each other for survival. Imagine a clownfish living in a sea anemone, the clownfish gets protection while the anemone gets food scraps.

A type of mutualistic relationship where the species involved benefit from the interaction, but it is not essential for their survival. Imagine a bird eating seeds from a plant, the bird gets food while the plant gets its seeds dispersed.

The first species to colonize a newly available habitat, often after a disturbance. These species can tolerate harsh conditions and start the process of ecological succession. Imagine lichens growing on bare rock after a volcanic eruption.

Ecological succession that occurs on newly exposed substrates, like bare rock or volcanic ash, where no soil is present initially. It is a slow process, starting with pioneer species. Think of a glacier retreating, exposing rock, then lichens colonizing the surface.

Ecological succession that occurs in areas where existing soil has been disturbed, but some life remains. It is a faster process than primary succession due to the presence of soil and seeds. Imagine a forest fire clearing a forest, but allowing seeds to remain, leading to the regrowth of trees.

A graph showing the relative abundance of different species in a community, ordered from the most abundant to the least abundant. It helps illustrate the community's structure and species diversity.

The destruction or degradation of natural habitats, leading to a decline in biodiversity. This is the most common cause of species loss globally.

The rate at which organic matter is created by autotrophs, like plants, through photosynthesis. It is the foundation of all food webs.

A lake with high levels of nutrients, often leading to excessive algal growth and low oxygen levels. Think of a lake with lots of 'plant life', potentially causing problems.

A lake with low levels of nutrients, characterized by clear water, high oxygen levels, and low primary productivity. Think of a lake with 'clean' water and limited plant growth.

The proportion of consumed food that is absorbed and assimilated by an organism, representing how efficiently they convert food into energy.

The proportion of assimilated food that is converted into new biomass or offspring by an organism, reflecting their ability to produce new life.

Organisms that feed on dead organic matter, like bacteria and fungi, playing a critical role in decomposition and nutrient cycling.

The evolution of similar traits in unrelated species due to similar environmental pressures. Think of dolphins and sharks both having streamlined bodies for swimming.

The study of the distribution of organisms across the globe, influenced by factors like historical events, climate, and species interactions. Think of mapping where different animals live around the world.

A plant that grows on another plant, but doesn't obtain nutrients from it. Imagine an orchid growing on a tree branch, using the tree for support but not taking its nutrients.

A measure of water lost from an ecosystem through evaporation and transpiration, reflecting the amount of water available for plant growth.

A mathematical model used to describe the dynamics of predator-prey interactions, showing how population sizes can fluctuate in response to each other.

The maximum amount of a resource that can be harvested without depleting the population, ensuring the resource can be used sustainably for future generations.

A debate in conservation biology about whether it is better to protect a single large reserve or several smaller reserves for biodiversity conservation.

A model explaining the number of species on an island as a balance between immigration and extinction rates, influenced by factors like island size and distance from the mainland.

A group of spatially separated populations of the same species connected by dispersal, allowing for gene flow and the potential for recolonization after extinction.

A group of interacting communities linked by dispersal, where species movements and interactions between communities influence their structure and diversity.

Speciation that occurs when two populations are geographically isolated, preventing gene flow and allowing them to evolve independently. Think of a river separating two populations of deer.

Speciation that occurs within a single, continuous population, without geographical isolation. This can happen due to different selection pressures or reproductive isolation mechanisms. Think of a species of insects adapting to different food sources within the same area.

An organism that relies on external sources of heat to regulate their body temperature, often referred to as cold-blooded. Think of a lizard basking in the sun to warm up.

An organism that generates its own body heat through metabolic processes, often referred to as warm-blooded. Think of a human maintaining a stable body temperature.

An organism that maintains a stable body temperature, regardless of external conditions, through internal regulation. Think of a mammal keeping its body temperature constant.

An organism with a fluctuating body temperature that varies with the environment, often referred to as cold-blooded. Think of a fish whose body temperature changes with the water temperature.

A factor that affects a population more strongly as population density increases. Think of competition for limited resources, becoming more intense with more individuals present.

A factor that affects a population regardless of its density. Think of a natural disaster like a wildfire, which can impact a population regardless of its size.

Two species with very similar ecological niches cannot coexist indefinitely; the superior competitor will outcompete the other, leading to its local extinction. Think of two species of birds competing for the same food source.

The full range of environmental conditions a species can tolerate, without competition from other species. Think of a lizard's ability to occupy a wide range of temperatures and habitats.

The narrower range of environmental conditions a species actually occupies in the presence of competition. Think of a lizard's actual range limited by a more dominant lizard.

A phenomenon in which population growth rate decreases at low population densities due to reduced reproductive success or survival. Think of a small population of birds struggling to find mates or defend their territory.

A species that has a disproportionately large impact on the structure and function of an ecosystem, often through interactions like predation or competition. The removal of a keystone species can have significant cascading effects on the community. Imagine a sea otter that helps control sea urchin populations, thus preventing kelp forests from being overgrazed.

The conversion of plant communities to desert or the expansion of desert into other communities, often due to factors like overgrazing, deforestation, and climate change.