BIOL 101 Ecology (copy)

Complete flashcard set of notes for bio unit one

Ecologists

Scientists who study natural ecosystems and organisms

Conservation Biologists

Study of Biodiversity with aim of protecting species

Environmentalists

Advocates for sustainable management of environment through policy and/or behavior changes

Rachel Carson

Marine Biologist who wrote “Silent Spring“ highlighting the effects of pesticides such as DDT

Wangari Maathai

Led Green Belt movement focused on replanting trees. Became the first African Woman to receive the Nobel Peace Prize

Jane Goodall

Anthropologist and Primatologist who studied chimpanzees

Chipko Movement

1970s movement in India wherein women would hug trees to prevent them from being cut down, defying the Indian government.

Ecology

Study of interactions between organisms and the environment

Ernest Haeckel

First to use ecology to explain natural relations, also drew a lot of trees of life to try and explain relationships between species

Organismal Ecology

organisms structure, physiology, evolution, and behavior

Population Ecology

Factors affecting population size over time (intraspecific level)

Community Ecology

Group of populations of diferent species (Interspecific Level)

Ecosystem Ecology

Community of organisms and abiotic factors (Emphasizes energy/chemical cycling)

Landscape Ecology

Mosaic of connected ecosystems (Focuses on exchanges of energy, materials, and organisms across ecosystems)

Global Ecology

Biosphere, sum of all planets ecosystems and landscapes (influence of energy and materials on organisms across biosphere)

Climate

Long term prevailing weather conditions in an area

Climate Components

Temperature, precipitation, Sunlight, and Wind

Abiotic Factors

Chemical and Physical Environment

Biotic Factors

Organisms, living environment

Cause of Global Climate Patterns

solar energy and earth’s movement through space

Where are deserts found?

23.5 degrees N/S (Tropic of cancer/Capricorn)

What causes seasonality?

tilt of Earth’s axis and elliptical orbit around the sun

Windward mountain side

Where it precipitates

Leeward mountain side

dry (often deserts on this side) (rainshadow)

Effects of vegetation on climate

More solar energy absorbed > more photosynthesis

More Transpiration > Cooler Atmosphere

Effects of Deforestation

Reduced photosynthesis and transpiration, warmer atmosphere

Biomes

Life zones characterized by vegetation

Climograph

Plots mean annual temperature and precipitation

Tropical Forest

Vertically layered, intense light competition, constant temperature (25-29 C)

Millions of Species

Rapid Human population and consumption a threat

Tropical Rainforest vs Tropical dry forests

Rainforests evergreen while dry forests lose their leaves

Savanna

Equatorial/Subequatorial, rain seasonality, precipitation average (30-50 cm), average temperature (24-29 C)

Dominated by forbs/grasses; fire and drought adapted

megaherbivores: wildebeests, zebras

Predators: Lions and Hyenas

Declines from cattle ranching and overpopulation

Broadleaf Forest

Mid latitudes in N Hemisphere, smaller areas in Chile, South Africa, and Australia

Annual Precipitation average 70-200 cm, significant rain/snow all seasons

Winters average 0 C Summers hot and humid (35 C)

Dominate trees: deciduous trees in NA, and Evergreen Eucalyptus in Australia

Mammals hibernate Birds Migrate in Winter

Most already destroyed by logging and urbanization

Northern Coniferous Forest

Largest of Biomes, “Taigas“, occurs at high northern latitude at edge of arctic

Annual precipitation 30-70 cm; winters cold, summers warm

ex. Siberia -50 C to > 20 C

Dominant plants - conifers (pine spruce, fir, hemlock)

Animals - migratory and resident birds: large mammals - moose, brown bears, tigers

Periodic insect outbreaks kill vast tracts of trees due to homogeneity of tree species

Some forests being logged at alarming rate

Population Ecology

Explores how biotic and abiotic factors influence density, distribution, and population size

Population

Group of indiviudals of the same species living in an area

Density

Number of individuals per unit area or volume

Dynamic process that stems from the result of addition and subtraction of individuals from the population

Dispersion

Pattern of spacing among individuals within a population

Clumped dispersion

patches of individuals from a population

Caused by nutrient availability, mating, and predation

Most Common

Uniform dispersion

Evenly spaced individuals from each other

Caused by territoriality, defense mechanisms,

Random dispersion

no given pattern

Caused by even distribution of resources and lack of controlling factors

Additions to population

Birth and immigration

Removals from the population

Death and emigration

Demography

Study of births, deaths, and migration rates of populations over time

Life table

Age specific summary of survival and reproductive rates within a population

Made by following a cohort from birth to death

In sexually reproducing species only females are considered

Survivorship curves

Graphic way of representing survival rate data on a life table

Plot proportion of members of cohort alive at each age

Type I, II, and III curves

Type I survivorship curve

High survivorship in early and middle life, decreased death rates in old age groups

ex. humans

Type II survivorship curve

Survivorship declines linearly, constant death rate over organisms

ex. ground squirrels

Type III survivorship curve

low survivorship due to high death rates for young age groups, and stable survivorship later in life due to lower death rates for survivors

Ex. oysters, many plants

What does change in population size equal?

Births + Immigrants - Deaths - Emigrants

Mathematical expression of population growth

ΔN/Δt = B-D

or

ΔN/Δt = R

where ΔN = change in population size, Δt = time interval, B = # of births, D = # of deaths, and R = difference of births and deaths

what is r_Δt

r_Δt is the average contribution of each individual to the population size over the time interval Δt

When does unlimited growth occur

ideal conditions (unlimited food and individuals reproducing at physiological capacity)

also found in populations in new environments or when they are rebounding after a catastrophic event

J shaped curve

Exponential population growth equation

dN/dt = rN

r = intrinsic rate of increase

N = population size

Intrinsic rate of increase (r)

A higher r means a steeper J shaped curve

Logistic Growth

Realistic model of populations wherein resources are limited by carrying capacity (k)

S shaped curve (sigmoid)

What happens as a population reaches its carrying capacity

per capita birthrate decreases and/or per capita death rate increases

growth rate drops

When is population growth highest

at ½ carrying capacity

Thomas Malthas

English economist and demographer know for his theory that population growth would outrun available resources

Life History

Traits that affect a species schedule of reproduction and survival

Age at which reproduction occurs

How often it reproduces

How many offspring are produced per reproductive episode

What do finite resources lead to

trade offs between survival and reproduction

number and size of offspring

Describe the offspring of species who are likely to die

they produce many small offspring

K-selection

Traits advantageous at high densities

r-selection

traits that maximize reproductive success at low densities

Density independent

Not affected by population density

Density dependent

Birth rate decreases or death rate increases as density increases

Biological Community

population of different species living close enough to interact

Competition

-/-

Species compete for limited resources — affects survival and reproduction of both species

ex. trees in the same forest, lions and cheetahs

Principle of Competitive Exclusion

2 species competing for a limiting resource cannot coexist in one place

competitive exclusion of inferior competitor

Georgy Gause

Russian biologist who formulated idea of competitive exclusion

Paramecium aurelia outcompeted Paramecium caudatum by using resources faster in his experiment

Ecological Niche

Specific set of abiotic and biotic resources used by an organism

Ecologically similar species can coexist if one or more significant differences in their niches

ex. DR Anoles

Spatial partitioning

competing species use different areas in a habitat to coexist

ex. DR anoles

Temporal partitioning

Species use the shared resources at different times to coexist

ex. hawks and owls

Fundamental niche

The niche a species can potentially occupy based on the range of conditions in which it grows and reproduces

Realized niche

The limited niche the species actually occupies when competing species are present

Character displacement

If character differences between two species are greater when populations are sympatric than allopatric it is called character displacement

Evidence of competition in the past

Galapagos Finches

Joseph Connell

Researched fundamental/realized niche through barnacles (chthamalus and balanus)

Formed idea of 5-6 linkages per food chain

Created intermediate disturbance theory after researching coral reefs and tropical rainforests with many disturbances and few disturbances

Sympatric

Same geographical area

Allopatric

Different geographical area

Ectoparasites

Parasites attaching to the outside of the body

ex. ticks, leeches

Endoparasites

Parasites inside the body

ex. tapeworms

Predation

+/- Beneficial to one harmful to the other

Predator kills and consumes prey

ex. Bears and fish, lions and zebras, lacewings and mice

Predator traits

acute senses, claws, fangs, venom

Prey adaptations

Behavioral: hiding, fleeing, herds/schools, active self defense

Morphological: Mechanical (spines, thick skin) (ex. Pachyderms, cacti), chemical (toxins) (ex. poison dart frogs)

Coloration

Cryptic coloration

Blending into the environment

ex. canyon tree frog

Aposematic coloration

Bright colors warning predators of toxins

ex. poison dart frog

Batesian mimicry

nonharmful species mimics harmful species

hawkmoth larva

Henry Walter Bates

English naturalist who provided explanation for mimicry

Parasitism

+/- Beneficial to one harmful to the other

Parasite uses hosts resources at the detriment of the host

Many have complex life cycles including many hosts

Some parasites affect behavior of host

Ex. ticks, tapeworms, and cuckoo bird

Herbivory (±)

An herbivore eats part of a plant/algae, harming but usually not killing it

Ex.

terrestrial: large mammals and small invertebrates (mostly small invertebrates)

Marine: sea urchins, fish, and some mammals

Herbivore adaptations

chemical sensors, specialized teeth or digestive systems

Plant adaptations to herbivory

chemical toxins, protective structures (spines, thorns)

Mutualism

+/+

Beneficial to both species

in some examples species can’t survive without each other

Each partner experiences a cost outweighed by the benefits of the interaction

ex. bees and flowers, mycorrhizae and trees, acacias and ants

Comensalism

+/0

beneficial to one other neither helped or hurt

hard to prove and highly debated

ex. barnacles on whales, epiphytic plants on trees, Junus gerardii and other plants in salt marshes

Amensalism

0/-

One unaffected other harmed

ex. Elephants and burrowing animals, penicillium and bacteria

THIS IS A BONUS CARD, IT IS NOT IN THE CURRICULUM

Species richness

Number of species in a community

Relative abundance

proportion each species represents of all individuals in the community

Species diversity

Measured by Shannon diversity index

determining species richness and relative abundance challenging for rare, mobile, or small species

molecular tools can be used to help determine microorganism biodiversity

Cedar Creek Ecosystem Science Reserve

Plant diversity was manipulated on different plots for more than two decades

In Minnesota

effect of high diversity

Communities more productive/stable

Better able to withstand and recover from environmental stress and introduced/exotic species

Able to produce more biomass

Trophic Structure

the feeding relationships between organisms in a community

key factor affecting community structure and dynamics