Ecology

photic zone

water region w/ sufficient light for photosynth

Hadley Cell

0-30 degs (N and S of equator)

• air warms @ equator → rises + releases moisture (over equator) → dry air masses around 30 degs, suck up moisture, create arid climate beneath → some descends back to Hadley, some descends into Ferrell

environment

surrounding conditions influencing life + behavior or orgs (biotic and biotic factors)

Ferrell Cell

30 - 60 degs latitude

• air @ surface is pulled from high pressure area (30 degs) to lower pressure area (60 degs) → air warms and rises @ 60 degs → flows towards 30 degs and sinks again

Polar cells

60-70 degs latitude

• cold air sinks near poles → rises around 60 degs latitude

structural hierarchy used to organize living systems (types of ecology)

Organismal

• org’s structure and behavior meet environmental challenges

Population (one species)

• factors affecting pop size/ changes and why

Community (2+ species)

• how interactions b/w species affect community structure/ organization

Ecosystem (one place)

• energy + chemical flow b/w orgs in environment

Landscape (many ecosystems)

• energy, material, org exchanges across ecosystems

Global

• regional E / material exchange influences fxn/ org distribution in biosphere

Type III survivorship curve

High early death rate then stabilization with age (ex. Oysters)

Type I survivorship curve

Low death, early midlife, sharp decline with age (large mammals)

density dependent factors of population growth

Affect larger pops. > smaller ones

1) Competition (limited resources- food, space, water)

2) Predation

3) Disease (spreads faster in crowded pops.)

density independent factors of population growth

affect all pops. equally regardless of density

1) natural disasters (wildfire, hurricane, flood)

2) climate change (drought, extreme temps)

3) humans (pollution, habitat destruction)

cohort

group of individuals of the same age in a population

seasonality

strong seasonal cycles in day length, temp, solar rad

Aquatic biomes

life zones characterized by their physical and chemical environment

• communities distributed according to water depth, light penetration, distance from shore, open water/ bottom dwelling orgs

terrestrial biomes

major life zones characterized by climate and vegetation type (also animals, fungi, microrogs)

• we live: Temperate Broadleaf forest

population

group of orgs of the SAME species living in same area; interact with one another

secondary succession

recolonization of an area where a disturbance removed some but NOT ALL orgs in that community

mutualism

both species benefit (+,+)

longevity

avg age ppl die in a particular country

commensalism

one species benefits; other unaffected (+,0)

predator-prey (species interxn)

one species preys on another (+,-)

Benthic zone

lowest level in aquatic biome; has organic + inorganic sediments; occupied by benthos

herbivory

animal consumes plant: (+,-) or (+,0)

TFR

Total fertility rate: avg # babies per woman in a particular country during her reproductive lifespan

primary succession

ecological succession in a lifeless area

• ex. on volcanic islan

ecological succession

transition in a community’s species composition after a disturbance; establishment of a community in area w/ ~no life

amensalism

negatively effects one species; other is not affected (-, 0)

parasitism

Parasite benefits at host’s expense (+,-)

• Endoparasites - live within

• Ectoparasites - live on outer surface

• parasites can change their host’s behavior to increase likelihood of transfer to another host

cryptic coloration

camouflage (a prey/ predator adaptation- falls under Exploitation)

interspecific interactions

relationships b/w species in the same community

K - Selection

reproductive strategy where species produce less offspring because they put more energy/ resources into raising them

• typical in stable environments w/ high competition for resources

• longer life spans, mature later

exponential growth

reproduction/ pop. growth w/ unlimited resources + w/out constraints

• J curve

demography

study of changes overtime in vital statistics of populations (especially birth / death rates)

• think Life Tables and Survivorship Curves

climograph

plot of annual mean temp (y-axis) and precipitation (x-axis) in a region

ecosystem

community of orgs in an area + the physical factors they interact with

Dispersion

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

• Pattern types: clumped, uniform, random

species richness

number of species in a community

relative abundance

the proportional abundance of different species within a community 

Trophic Structure

feeding relationships b/w orgs in a community

• key factor affecting community structure

food chain

link trophic levels from producers to top carnivores (consumers)

trophic level

position an org occupies in food chain

food web

group of food chains linked by complex trophic interactions

• arrows point: eaten → consumer

foundation species

have strong effects on their community due to their large size/ high abundance

• ex. coral

keystone species

usually not abundant, control community structure through ecological roles

• many = apex predators

• critical to ecosystem diversity/ stability

• removal would change type/ number of species/ their population size at multiple trophic levels

ecosystem engineers

physically change environment → affects community structure (ex. beavers)

ecological niche

specific set of abiotic + biotic resources an org uses in its environment

Resource partitioning

ecologically similar species coexist given one or more significant differences in their niches

• related: fundamental and realized niches

Realized niche

actual resources a species uses given its environment / competition (not its ideal)

Fundamental niche

the potential/ ideal resources available for a species (no competition)

ecotone

transition area b/w ecosystems / biomes

disturbance

event that changes a community → removing organisms & changing resource availability

• storm, fire, humans

biosphere

global ecosystem

phyllotaxy

way to classify trees

• pattern of leaf arrangement on stem or branch

climate

long-term prevailing weather conditions in given area

• Factors: temp, precip, sunlight, wind

• determines distribution of terrestrial biomes/ where orgs can live

phytography

branch of botany for description, naming & classification of plants

biotic factors

LIVING parts of environment → influence distribution/ abundance of organisms

abiotic factors

NONLIVING chemical / physical attributes of environment → influence distribution/ abundance of organisms

• were never living

Ecology

scientific study of interactions b/w organisms & their environment

• greek: “home study”

estuary

region where fresh and salty marine waters mix

• Chesapeake is largest estuary in US

Population Density

number of individuals of population / unit area (where they live)

what kinds of species tend to have stepwise survivorship curves? (?)

molting species (periods of vulnerability)

biggest cause of seasonality

earth’s tilted axis & its orbit around sun

two major climatic factors affecting org distribution in terrestrial ecosystems

temperature and precipitation

Carrying Capacity

(K) Max population size that can be supported by available resources in a habitat (given no degradation of that habitat)

what does r stand for in population growth models?

The per capita population growth rate (equal to per capita birth rate minus per capita death rate)

Type II survivorship curve

a constant decline with a constant death rate over the life span

Why do some invertebrates, such as lobsters, show a "stair-step" survivorship curve?

vulnerable to predation during molting when their shell is soft

Which of the biomes (of the 7) require periodic fires to maintain their existence? (?)

savanna, chaparral, temperate grassland, and coniferous forest

aphotic zone

water region w/ very little light (insufficient for photosynth)

• orgs here have to rely on other energy gains (ex. chemosynth)

pelagic zone (aquatic)

the photic and aphotic zones together

• covers the majority of the ocean

benthos

communities of orgs living on, in, or near bottom of aquatic biome (benthic zone)

Littoral zone (aquatic)

waters close to shore; shallow enough for rooted plants

Limnetic zone (aquatic)

waters farther from shore; too deep for rooted plants

thermocline

narrow layer of abrupt temp change (in oceans / temperate lake zones)

Dispersal

movement of individuals or gametes away from their origin area / centers of high population

• contributes to global distribution of organisms

Limiting Factors for Species distribution (?)

Dispersal

Biotic Factors (other species)

Abiotic Factors (temp, water, O2, salinity, sunlight, rocks/ soil)