BIO130 Ecology Sonntag

What is ecology?

Ecology is the study of how organisms interact with one another and with their environment.

What are the primary goals of ecology?

To understand the distribution (where organisms occur) and abundance (how many there are) of organisms.

What are abiotic factors?

Nonliving environmental factors such as temperature, rainfall, sunlight, wind, water flow, and nutrient levels. Example: low rainfall limits which plants can grow in a desert.

What are biotic factors?

Living factors and interactions such as food, predators, competitors, habitat-forming organisms, and symbiotic partners. Example: tall trees shade shorter plants.

How can biotic and abiotic factors affect each other? [Introduction to Ecology]

They are interconnected. Abiotic conditions affect which organisms can live in an area, while organisms can change conditions—for example, dense vegetation can increase humidity and reduce light beneath the canopy.

What is organismal ecology? [Introduction to Ecology]

Study of traits of an individual organism or species, including morphology, physiology, behavior, and how it survives in a particular area. Example: how a cactus conserves water.

What is population ecology? [Introduction to Ecology]

Study of one species in an area, including its distribution, size, and changes over time. Example: tracking deer numbers in a forest.

What is community ecology? [Introduction to Ecology]

Study of interactions among populations of different species and the consequences of those interactions. Example: wolves, deer, and plants affecting one another.

What is ecosystem ecology? [Introduction to Ecology]

Study of organisms plus abiotic components and the transfer of energy and nutrients among organisms, soil, water, and atmosphere.

What is global ecology? [Introduction to Ecology]

Study of broad patterns involving the biosphere, global systems, and human impacts. The biosphere is the thin zone of Earth where life exists.

What is conservation biology? [Introduction to Ecology]

Efforts to protect and restore threatened genetic diversity at different levels.

How do the notes distinguish an ecologist from an environmentalist? [Introduction to Ecology]

The notes describe an ecologist as a scientist and an environmentalist as someone involved in environmental advocacy or politics.

How do interactions affect species distribution? [Introduction to Ecology]

A species may only live where its food, host, or other required species is present; predators or competitors may prevent it from occupying certain places.

What is dispersal? [Introduction to Ecology]

Movement of organisms, seeds, or spores away from a parent or birthplace to a new location. Example: wind carries dandelion seeds to another lawn.

Why does Pangaea matter to biogeography? [Introduction to Ecology]

Pangaea was a supercontinent when landmasses were connected. After continents separated, oceans became barriers that limited the movement of many land organisms.

What is an exotic or non-native species? [Introduction to Ecology]

A species occurring outside its original native range, often because humans moved it.

What is an invasive species? [Introduction to Ecology]

A species that spreads and outcompetes other organisms, negatively affecting biodiversity. Not every non-native species becomes invasive.

Can a native species act invasively? [Introduction to Ecology]

Yes. If a controlling predator disappears, a native species may increase greatly and overwhelm other species.

Why might a non-native species become invasive? [Introduction to Ecology]

It may escape predators, diseases, or other controls found in its native range and may disperse effectively in the new environment.

What is weather? [Weather, Climate, Biomes, and Productivity]

Day-to-day atmospheric conditions, such as today's rain, wind, or temperature.

What is climate? [Weather, Climate, Biomes, and Productivity]

Long-term patterns in atmospheric conditions. One hot day does not mean a region has a hot climate.

What defines a terrestrial biome? [Weather, Climate, Biomes, and Productivity]

A geographically and climatically defined region with a characteristic climate and organisms. Temperature, moisture, sunlight, and wind help shape it.

What are the six terrestrial biomes listed in the notes? [Weather, Climate, Biomes, and Productivity]

Arctic tundra, boreal forest, temperate forest, temperate grassland, subtropical desert, and tropical wet forest.

What is an Arctic tundra example? [Weather, Climate, Biomes, and Productivity]

A cold region with a short growing season where low temperatures limit tree growth.

What is a boreal forest example? [Weather, Climate, Biomes, and Productivity]

A cold forest dominated by conifers such as spruce and fir.

What is a temperate forest example? [Weather, Climate, Biomes, and Productivity]

A seasonal forest where trees such as maples may shed leaves in autumn.

What is a temperate grassland example? [Weather, Climate, Biomes, and Productivity]

A prairie where grasses dominate and seasonal conditions limit extensive tree growth.

What is a subtropical desert example? [Weather, Climate, Biomes, and Productivity]

A very dry region where plants must cope with limited water.

What is a tropical wet forest example? [Weather, Climate, Biomes, and Productivity]

A warm, rainy forest with dense vegetation and high biodiversity.

What are anthropogenic biomes? [Weather, Climate, Biomes, and Productivity]

Biomes strongly impacted or shaped by human activity.

Which eight anthropogenic-biome names are in the notes? [Weather, Climate, Biomes, and Productivity]

Tropical grassland, montane grassland, flooded grassland, mangrove, Mediterranean forest, temperate coniferous forest, tropical dry forest, and tropical coniferous forest. Memorize the course's list as given.

What is biomass? [Weather, Climate, Biomes, and Productivity]

The notes describe biomass as living material and refer to its carbon. In general, biomass is the mass of living biological material in an area.

What is aboveground biomass? [Weather, Climate, Biomes, and Productivity]

The mass of living plants above the ground, excluding roots. The notes say it can be used as an estimate of NPP.

What is net primary productivity (NPP) according to the notes? [Weather, Climate, Biomes, and Productivity]

The organic material available as food for other organisms, produced by primary producers after their own energy use is accounted for.

What determines aquatic biomes? [Weather, Climate, Biomes, and Productivity]

Salinity, water depth and light penetration, water flow, and nutrient availability.

What is an oligotrophic aquatic system? [Weather, Climate, Biomes, and Productivity]

A nutrient-poor system, often with relatively low algal productivity.

What is a eutrophic aquatic system? [Weather, Climate, Biomes, and Productivity]

A nutrient-rich system that can support substantial algal growth.

What are the five aquatic biomes listed in the notes? [Weather, Climate, Biomes, and Productivity]

Lakes and ponds, freshwater wetlands, streams, estuaries, and oceans.

Why is the ocean intertidal zone productive according to the notes? [Weather, Climate, Biomes, and Productivity]

It receives light and nutrients, supporting high productivity.

Why is the lake littoral zone productive according to the notes? [Weather, Climate, Biomes, and Productivity]

The shallow shoreline zone receives light and nutrients that support plant growth.

What happens in a lake's benthic zone? [Weather, Climate, Biomes, and Productivity]

Nutrients and organic material settle and accumulate at the bottom; turnover can return nutrients to the water column.

What is behavioral ecology? [Behavioral Ecology]

The study of how organisms respond to stimuli in their environment, including other organisms and abiotic factors.

What is mutualism? [Behavioral Ecology]

An interaction in which both species benefit (+/+). Example: a bee obtains nectar while pollinating a flower.

What is competition? [Behavioral Ecology]

Two or more organisms use the same limited resource; both may pay costs such as lost energy or reduced access to the resource (−/−).

What is predation? [Behavioral Ecology]

An interaction in which a predator benefits by consuming prey and the prey is harmed (+/−). Example: a hawk eating a mouse.

What is commensalism? [Behavioral Ecology]

One species benefits while the other is unaffected (+/0). The notes' example is a dung beetle using feces left by another animal.

What is amensalism? [Behavioral Ecology]

One species is harmed while the other is unaffected (−/0). The notes' example is an elephant stepping on a beetle.

What is proximate or mechanistic causation? [Behavioral Ecology]

How a behavior happens, including genetic, neurological, hormonal, or muscular mechanisms. Example: a hormone triggers a seasonal behavior.

What is ultimate or evolutionary causation? [Behavioral Ecology]

Why a behavior may have evolved through natural selection. Example: fleeing a fight can improve survival and future reproductive success.

What is innate behavior? [Behavioral Ecology]

Behavior that is genetically inherited rather than learned through individual experience.

What is learned behavior? [Behavioral Ecology]

Behavior shaped by experience during an individual's life. Example: an animal learns to associate a sound with food.

What is cost-benefit analysis of behavior? [Behavioral Ecology]

Comparing benefits such as food or reproduction with costs such as energy, time, and injury risk.

What five behavioral questions are listed in the notes? [Behavioral Ecology]

What should I eat? Who should I mate with? Where should I live? How should I communicate? When should I cooperate?

What is foraging? [Behavioral Ecology]

Searching for food; decisions include whether to move or stay, chase or wait, and accept or avoid risk.

What is optimal foraging? [Behavioral Ecology]

Choosing feeding behavior that maximizes feeding efficiency. If obtaining food costs more energy than the food provides, it may not be worthwhile.

What is sexual dimorphism? [Behavioral Ecology]

Differences in appearance between males and females of the same species. Example: male peacocks have showy tails while females are less conspicuous.

What can trigger mating behavior? [Behavioral Ecology]

Hormones, seasonal changes, environmental stimuli, and sexual selection.

What trade-offs affect migration? [Behavioral Ecology]

An animal weighs the costs of moving against benefits such as food, breeding conditions, or seasonal habitat; staying also has costs such as territory defense and resource limits.

What are piloting and compass orientation? [Behavioral Ecology]

Piloting uses landmarks; compass orientation uses directional cues to help an animal navigate.

What is communication in behavioral ecology? [Behavioral Ecology]

A signal from one individual changes another individual's behavior. It may occur within or between species and can be used for defense, mating, or group coordination.

What is kin selection? [Behavioral Ecology]

Behavior that can favor the survival or reproduction of genetic relatives, potentially increasing the spread of shared genes. Example: an alarm call may warn nearby relatives of a predator.

What is manipulation or cheating in cooperation? [Behavioral Ecology]

An individual benefits from a group or system without contributing proportionately. If too many individuals do this, cooperation can break down.

What is a population? [Population Ecology]

Potentially or actually interacting individuals of the same species in the same area.

What is a metapopulation? [Population Ecology]

A population of separate populations connected by migration. Example: frog populations in several ponds with occasional movement between ponds.

What is population density? [Population Ecology]

Number of individuals per unit of space or area. Example: 100 rabbits in 10 hectares = 10 rabbits per hectare.

What is random distribution? [Population Ecology]

Individual positions are independent of one another; locations may be unpredictable.

What is clumped distribution? [Population Ecology]

Individuals occur in patches because resources are patchy or because of social interactions. Example: zebras gathering near water.

What is uniform distribution? [Population Ecology]

Individuals are spaced relatively evenly, often because of territoriality or competition.

What is demography? [Population Ecology]

Study of births, deaths, immigration, and emigration and how they affect a population.

What is age structure? [Population Ecology]

The number of individuals in age classes such as juveniles, subadults, and adults.

What is generation time according to the notes? [Population Ecology]

The average time between a mother's first offspring and her daughter's first offspring.

How do the notes distinguish r-strategists and K-strategists? [Population Ecology]

r-strategists are associated with a high intrinsic rate of increase; K-strategists are associated with carrying capacity. These are simplified ends of a continuum.

What do ΔN and Δt mean? [Population Ecology]

ΔN is change in the number of individuals; Δt is change in time.

What does r mean in population growth? [Population Ecology]

Per-capita rate of increase, reflecting births minus deaths in the simplified notes; it can be negative.

What is rmax? [Population Ecology]

The intrinsic maximum rate of increase under optimal conditions, with high birth rates and low death rates.

What equation for exponential growth appears in the notes? [Population Ecology]

ΔN/Δt = rmax N.

What is exponential growth? [Population Ecology]

Growth in which the per-capita rate of increase does not change over time; it can produce a J-shaped curve when resources are abundant.

When can density-independent growth be seen? [Population Ecology]

When growth is not dependent on population density; the notes give newly founded populations and populations rebounding after devastation as examples.

What is density-dependent growth? [Population Ecology]

Growth affected by population density; as density rises, death rates may increase and birth rates may decrease.

What is carrying capacity (K)? [Population Ecology]

The maximum number of individuals a habitat can sustain over a sustained period under the prevailing conditions.

What is logistic growth? [Population Ecology]

Population growth in which the growth rate changes with population size and slows as the population approaches carrying capacity.

Give examples of density-independent limits. [Population Ecology]

Hurricanes and volcanic eruptions can affect populations regardless of their density.

Give examples of density-dependent limits. [Population Ecology]

Disease transmission, aggression, and resource scarcity can have stronger effects at high density.

What is a Type I survivorship curve? [Population Ecology]

High survivorship early and middle in life, with mortality increasing late in life; the notes give humans as an example.

What is a Type II survivorship curve? [Population Ecology]

A relatively uniform chance of survivorship or mortality throughout the life cycle; the notes give small mammals as an example.

What is a Type III survivorship curve? [Population Ecology]

Low survivorship early in life but higher survivorship among those that survive the early stage; the notes give sea turtles as an example.

What is population dynamics? [Population Ecology]

Changes in populations across space and time, including interactions, migration among populations, and population cycles.

What is a community? [Community Ecology]

All the species that interact in a given area.

What are three themes in community ecology from the notes? [Community Ecology]

Species interactions affect distribution and abundance; species can act as agents of natural selection; and interaction outcomes are dynamic and conditional.

What is coevolution? [Community Ecology]

When interacting species influence each other's evolution over time. Example: a plant evolves defenses and an herbivore evolves ways to overcome them.

What is a niche? [Community Ecology]

The resources and conditions a population needs to live, survive, and reproduce.

What is niche overlap? [Community Ecology]

When species use some of the same resources or conditions, potentially leading to competition.

What is intraspecific competition? [Community Ecology]

Competition among members of the same species. Example: two oak seedlings competing for sunlight.

What is interspecific competition? [Community Ecology]

Competition between different species. Example: an oak and a maple competing for light.

What is the competitive exclusion principle? [Community Ecology]

If two species compete for the same limiting resource in the same niche, one may outcompete and locally exclude the other.

What is a fundamental niche? [Community Ecology]

The full range of environmental conditions and resources where a species could potentially survive, grow, and reproduce without limiting pressures such as competitors or predators.

What is a realized niche? [Community Ecology]

The actual conditions and resources a species occupies after real-world pressures such as competition and predation are considered.

What is resource partitioning? [Community Ecology]

Species divide resource use to reduce overlap and competition. Example: bird species feed in different parts of the same tree.

What is niche differentiation? [Community Ecology]

Evolutionary divergence in resource use that reduces competition; the notes connect this with character displacement.

What is herbivory? [Community Ecology]

Consumption of plant material. Example: a caterpillar eating a leaf.