Bio5C Exam 1

Ecology

The study of the relationship between organisms and how they interact with their environment

Components of Ecosystem

Abiotic and biotic factors

Abiotic Factors

All non-living components in an ecosystem

Biotic Factors

All living components in an ecosystem

The various scales of ecology

Global, landscape, ecosystem, community, population, organismal

Global scale

About earth as a whole

Landscape

Influences across multiple ecosystems

Ecosystem

Relationship between the ecosystem and organisms

Community

Difference between predation and competition

Population

Influences on the population

Organismal

Influences on individual organisms

The general process of natural selection

An organism that adapts the best to its environment, includes survivors and the ones that die

Climate

The long term weather conditions in an area

Weather

The short term conditions in a specific area

What determines global climate patterns

Solar energy, earth's movement, shape of the earth

What climate is composed of

Temperature, precipitation, sunlight, wind

How Earth's shape contributes to global air, precipitation, and ocean current patterns

Due to Earth's shape, the sun will hit it at different angles

Regions of Earth by latitude

North pole (90 N)

temperate (66.5 N)

tropic of cancer (23.5 N)

equator (0)

tropic of capricorn (23.5 S)

temperate (66.5 S)

south pole (90 S)

Names of global air circulation

Easterlies (poles)

westerlies (temperate)

northeast trades (tropics)

southeast trades (tropics)

What produces seasons and what occurs at each solstice and equinox

Earth's tilt 23.5°

The gyre that produces cooler climates in California and warmer ones in the UK

North pacific subtropical gyre

The effect of mountains on local climate

Cool air flow upwards, releases moisture, and creates a rain shadow (influence air flow over land)

Climate Change

A directional change in climate that lasts over 3 decades or more

The major characteristics that determine where aquatic and terrestrial organisms reside

Climate, light and nutrient availability

Where terrestrial organisms live

climate

Where aquatic organisms live

light and nutrient availability

Biome

Distribution of life at a grand scale

Why latitude is not the only determinant of biomes

Proximity to water

Tropical Forests

Equatorial, 200-400 cm, 25-29, vertically layered, broad leaf plants, bigger trees

Desert

Tropics, less than 30 cm, day 450, night -30, drought and heat tolerant, protected herbivory

Savannah

Equatorial and subequatorial, 30-50 cm, 24-29, drought tolerant, heat adapted, grasses, forts

Chapparal

Circumpolar belt, 30-50 cm, fall winter spring 10-12, summer 40, fire and drought tolerant, high species density

Grassland

Circumpolar belt, 30-100 cm, winter -10, summer 30, long droughts and fires, grazing prevents tree development, highly seasonal, periodic droughts

Coniferous Forest

Circumpolar belt, 30-70 cm, cold winters, hot summers, needle leaf, evergreen trees, fire adapted

Broadleaf Forest

Circumpolar belt, 70-200 cm, winter 0, summer 35, vertical layering, deciduous trees

Tradeoffs that plants make in photosynthetic tissue/structure and transpiration

They adapt to different environments

How zonation is characterized in lake and marine environment

Light penetration, distance fro shore and depth, open water and bottom

Light penetration

Photic and aphotic

Photic

Most light

Aphotic

No light

Distance from shore and depth

Littoral, Limnetic, intertidal, nertic, oceanic

Littoral

Close to shore, higher depth

Limnetic

Away from shore, deeper depth

Intertidal

submerged in water sometimes, no water other times

Nertic

Little bit farther out

Oceanic

Out in ocean

Open water and bottom

Pelagic, benthic, abyssal

Pelagic

Out in open water

Benthic

close to bottom

Abyssal

Bottom of ocean

Environmental Heterogeneity

Environment varies dramatically around the globe

Biological Tradeoffs

An organism cannot be all things

How environmental heterogeneity and biological tradeoffs relate to the diversity to organism on Earth

Both factors that contribute to a species selective diversity being the traits they give off and their advantages in a given environment

The feedback loop between ecological and evolutionary change

Ecological change, alters selective pressure on organisms, evolutionary change, alters outcome of ecological interactions

Phenotypic plasticity

Changes in morphology, physiology, or behavior due to the environment

Adaption

Changes in morphology, physiology, or behavior due to genetics

The Clausen, Keck, and Hiesey experiment

Variation in plants based on altitude (observation) genes, environment, different species (hypothesis), differences in morphology and physiology (observed)

The general process of species dispersal and local adaptation

Species disperse to new area, environment puts pressure on species, some die some live, newly established species affect local ecoloy

Why is Species absent from area X?

Dispersal limits: area inaccessible or insufficient time

Biotic limits: predation, parasitism, disease

Abiotic Limits: water, oxygen salinity, ph (chemical), temperature, light, soil structure (physical)

Abiotic factors limiting distribution

Temperature, water, salinity, sunlight, rocks, soil

Biotic factors limiting distribution

Predation, herbivory, mates, competition, resources, disease

Two Principles of ecology

All populations tend to grow exponentially under ideal conditions, no population can grow exponentially forever

Population

A group of interbreeding organisms in the same geographic area

Population Ecology

Examines the dynamics of whole populations in relation to their environment

Density

The number of individuals in an area

Dispersion

Pattern of local densities

Density is influenced by

Process that add and remove individuals

Density is calculated by

Dividing the raw number of individuals by unit area

Patterns of Dispersion

Clumped, uniform, random

Clumped

Grouped together where food is abundant

Uniform

Aggro neighbors maintain even spacing

Random

Seeds fall and establish where they an

Life Tables

Measure population increase and decrease over a set period of time

Proportion alive

Number alive / initial number alive (lx)

Death rate

Initial number alive - number alive and then divide by initial number alive (dx)

Survivorship curve

Type 1: low death rates until old age (humans)

Type 2: constant death rates over lifetime (squirrels)

Type 3: high death rates at young age (long-lived plants)

Type 1

Low death rates until old age

Type 2

Constant death rates throughout lifetime

Type 3

High death rates at young age

What Ideal conditions mean

Conditions that allow species to reproduce and grow comfortably (food, water, sunlight,etc)

What leads to population dynamics

Ideal conditions

Population Dynamics

Mathematics used to study the size and age composition of populations over time

How we study population dynamics

Immigrant and emigration of one of more species

What are the kinds of patterns we observe in population dynamics

Mortality rates or movement in and out (in seasons or annually), show adverse effects of environmental damage of populations

Thomas Malthus's Important Oberservation

While population increases exponentially, food supply increases linearly

The reasons for modeling exponential population growth

To see how quickly a population is capable of growing and to see how populations will grow when colonizing new areas or rebounding

The factors that go into population size

Add births and immigration, subtract death and emigration

Closed population

set immigration and emigration at 0

N

Raw population interval

B

Births

D

Deaths

R

The difference in births and deaths during a specific time interval

b

Per capita birth

d

Per capita death

r

per capita differences in birth and death rate

dN

derivative tells us at specific instant in time

∆N

Change in population number

∆t

Time interval

Per capita difference in birth and death rate

r=b-d

Per capita difference in birth and death rate

r=b-d