Unit 4 - Ecology

Ecology

the scientific study of the interactions between organisms and the environment

Climate

the long term prevailing weather conditions in a given area. Determined by precipitation and temperature

Macroclimate Patterns

work at the global, regional, and the local level.

Example: Changing angle of the sun, bodies of water, and mountains exert seasonal, regional, and local effects on this

Microclimate

determined by fine scale variations

Example: sunlight and temperature under a log

Biomes

the major types of ecosystems that occupy very broad geographic regions. Determined by climate

Climograph

A graph depicting the annual mean temp(C) and the annual mean precipitation(cm) of the biomes

Desert

little rainfall. Plants and animals are adapted to conserve water. Contain CAM plants and plants that have defenses like spines against predatory animals. Temperatures are extreme(hot and cold)

Chaparral

has dense, spiny, evergreen shrubs. coastal areas with mild rainy winters and long, hot, dry summers. Plants are adapted to fire

Temperate Grasslands

marked by seasonal drought with occasional fires and have large grazing mammals. These factors prevent the growth of trees. Soil is full of nutrients

Temperate Broadleaf Forests

dense groups of deciduous trees that need rain. Stratified, meaning they have multiple layers (top strata-trees. Bottom Strata-shrub). In winter, trees drop their leaves, mammals enter hibernation, and birds migrate to warmer climates

Canopy

the upper layers of trees in a forest

Coniferous Forests

has cone-bearing trees like pine, spruce, etc. The cone shape of conifers prevent much snowfall from accumulating and breaking the trees' branches

Tundra

marked by permafrost(permanently frozen layer of soil), cold temps., high winds, and little rainfall. Does not support a lot of plant life

Tropical Rain Forest

vertical stratification. Canopy is dense enough to where little light can pass through. Has epiphytes(plants that grow on other plants instead of soil) Rainfall varies by season. Has the greatest biodiversity of all terrestrial biomes

Aquatic Biome

makes up the largest part of the biosphere since water roughly covers 75% of the Earth.

Classified into freshwater or marine biomes

Some display vertical stratification

Freshwater Biome

An aquatic biome that contains water(low salinity) and is categorized into standing(still) bodies of water like lakes and estuaries and moving bodies of water like rivers and streams

Marine Biome

an aquatic biome that contains water(high salinity) and is categorized into bodies of water like oceans

Photic Zone

in an aquatic biome, an area where the depth is shallow enough to where there is enough light for photosynthesis

Aphotic Zone

in an aquatic biome, an area where the depth is deep enough to where there is little to no light, so very little photosynthesis occurs

2 Types of Freshwater Biomes

Standing Bodies of water-Estuaries, Lakes, etc

Moving Bodies of water-Rivers, Streams, etc

Oligotrophic Lakes

deep lakes that are nutrient poor and oxygen rich and contain sparse phytoplankton

Eutrophic Lakes

shallow lakes that are nutrient rich but oxygen poor and contain a high concentration of phytoplankton

Streams and Rivers

a freshwater biome where currents are prominent

organisms are distributed in vertical zones and from the headwaters to the mouth

Estuaries

areas where freshwater streams or rivers merge with the ocean. Among the most productive habitats on Earth

Coral Reefs

a biome created by a group of cnidarians that secrete hard calcium carbonate shells, which vary in shape and support the growth of other corals, sponges, and algae

Biotic

living

Abiotic

nonliving

Abiotic Factors

the nonliving, chemical, and physical components

Ex: Temperature, Sunlight, Water, Salinity, and Soil

Biotic Factors

living components and may include behaviors as well as interactions with other species

Population

a group of individuals of a single species living in the same general area

Population Ecology

explores how abiotic and biotic factors influence the density, distribution, size, and age structure of populations

Density

number of individuals per unit area or volume

Dispersion

the pattern of spacing among individuals within the boundaries of a population

Uniform Dispersion

often the result of unfriendly interactions.

Ex:Animals that defend territory

Random Dispersion

unpredictable spacing. Not a common spacing in nature because there is usually a reason for a pattern of spacing

Clumped Dispersion

the most common pattern. individuals are in patches, usually around a required resource

Ex:Schools of Fish

Demography

the study of vital statistics of a population, especially birth and date rates

Type 1 Survivorship Curve

shows low death rates during early and middle life then the death rate increases sharply in older age groups. Typical pattern for organisms with a long life span

Type 2 Survivorship Curve

shows a constant death rate over the organism's life span

typical pattern for organisms that are heavily preyed upon

Type 3 Survivorship Curve

shows very high early death rates, then a flat rate for the few surviving to older age groups.

Infanticide-the killing of many infants

Exponential Population Growth

refers to population growth under ideal conditions

Carrying Capacity

defined by the maximum population size that a certain environment can support at a particular time with no degradation of the habitat

represented by K

Logistic Growth Model

the amount of organisms added to a population slowly decreases when approaching the carrying capacity

Life History

traits that affect an organism's schedule of reproduction and survival

how early?

how often?

how many?

Semelparity

when organisms save their resources for one big reproductive event. also known as big bang reproduction

Iteroparity

when organisms produce offspring repeatedly.

also known as repeated reproduction

K-Selection

selection of life history traits that are sensitive to population density and carrying capacity

r-Selection

selection for life history that maximize reproductive success

Density Dependent Factors

factors that have different magnitudes depending on how many organisms there are per square unit

Competition for Resources

as population density increases, this intensifies.

examples are: food, space, or essential nutrients

density dependent

Territoriality

available space for territories or nesting may be limited, thus controlling the population

density dependent

Disease

increasing densities allow for easier transmission of illness

density dependent

Predation

as prey population increases, predators may find the prey more easily

density dependent

Density Independent

when the death rate does not change depending on the density of the population

includes natural disasters

Demographic Transition

when a population goes from high birth rates and high death rates to low birth rates and low death rates

Age Structure Pyramids

shows the relative number of individuals of each age in a population and can be used to predict and explain many demographic patterns

Rapid Growth Age Structure Pyramid

less people dying more people being born

Slow Growth Age Structure Pyramid

there is a slightly higher number of people being born than people dying

No Growth Age Structure Pyramid

the amount of people dying and being born are roughly the same

Ecological Footprint

the total land and water area needed for all resources a person consumes in a population

Interspecific Interactions

interactions between species

can be positive, negative, or neutral

includes competition, predation, and symbioses

Community

a group of populations of different species living close enough to interact

Interspecific Competition

occur when resources are in short supply

it is a negative/negative interaction for the involved species

Competitive Exclusion Principle

when two species are battling for a resource, eventually one with the slight reproductive advantage will eliminate the other

Ecological Niche

the sum total of biotic and abiotic resources that the species uses in its environment

Fundamental Niche

the niche that the species usually occupies

Realized Niche

the portion of the fundamental niche the species actually occupies

this can turn into a fundamental niche

Predation Interaction

a positive/negative interaction

the predator eats the prey

Aposematic Coloration

warning coloration

a poisonous animal is brightly colored as a warning to other animals

Cryptic Coloration

the animal is camouflaged by its coloring

Batesian Mimicry

a harmless species has evolved to mimic the coloration of a harmful species

Mullerian Mimicry

tow bad-tasting species resemble each other, apparently so that predators will learn to avoid each one equally

Herbivory

a positive/negative interaction in which the herbivore eats part of the plant or algae

Symbiosis

when individuals of two or more species live in direct contact with each other

Parasitism

a positive/negative interaction in which the parasite derives its nourishment from the host.

the parasite however does not kill the host, sine the host has to be living in order for the parasite to also survive

ex: ticks and dogs

Mutualism

a positive/positive interaction that benefits both species

ex: a pollinator and flowering plants

Commensalism

is a positive/neutral interaction in which one species benefits but the other does not benefit or is harmed

ex: a fern growing in the shade of another plant

Species Diversity

measures the number of different species in a community(species richness) and the relative abundance of each species

Trophic Structure

the feeding relationships among the organisms

Trophic Levels

the links in the trophic structure of the community

Food Chain

the transfer of energy from plants through herbivores through carnivores through decomposers

from one trophic level to another

Food Web

food chains linked together

Species Richness

the number of different species in a community

Dominant Species

the species with the highest biomass or are the most abundant

Biomass

the sum weight of all the members of a population

Keystone Species

exert control on community structure by their important ecological niche

Disturbance

natural disasters like storms, fires, floods, etc.

removes organisms or changes the resource availability

some disturbance is good as it could create conditions that foster high species diversity(intermediate disturbance hypothesis)

Ecological Succession

refers to transitions in species composition in a certain area over ecological time

Primary Succession

plants and animals gradually invade a region that was virtually lifeless where soil has not yet formed

ex: colonization of a newly formed volcanic island

Secondary Succession

occurs when an existing community has been cleared a disturbance that leaves the soil intact

Island Biogeography

influenced by two factors

the greater the size of the island, the higher immigration rates will be and the lower the rates of extinction

as the distance from the mainland increases, the rate of immigration falls, whereas extinction rates increase

Ecosystem

the sum of all the organisms living within boundaries(biotic community) and all the abiotic factors in which they interact

Primary Producers

the autotrophs

supports all other organisms in the ecosystem

Heterotrophs

consumers

Primary Consumers

herbivores that eat primary producers

Secondary Consumers

carnivores that eat herbivores

Tertiary Consumers

carnivores that eat secondary consumers

Detritovores

decomposers

consumers that get their energy from detritus, which is nonliving organic material such as the remains of dead organisms, feces, dead leaves, and wood

recycle nutrients back into the ecosystem

Primary Production

the amount of light energy converted into chemical energy by autotrophs

Gross Primary Production

GPP

the total primary production of the ecosystem