ecology mongo review

Chapters 50-54

Innate behaviors

– _{Fixed action patterns (FAPs)}

• _{innate behaviors that exhibit unchangeable}

sequences

• _{Ensure that activities essential to survival}

are performed correctly without practice

– _{Sign stimuli are simple cues that trigger fixed}

action patterns

http://www.youtube.com/watch?v=uMnekeLT Urw

Movement in response to a stimulus

•

Kinesis: a simple change in activity in response

to a stimulus

•

Taxis: an oriented movement toward or away

Animal signals and communication

•

Signal: a behavior that causes a change in

another animal’s behavior

– _{chemical, visual, auditory, tactile, electrical}

modalities

– _{http://www.youtube.com/watch?v=PaNX6pJsIT0&}

Learning #1

•

Imprinting

– _{Generally irreversible}

– _{Involves learning and innate behaviors}

Learning #2

– _{Habituation is learning to ignore a repeated,}

– _{Spatial learning}

• _{Involves using landmarks to move through the} environment

• _{Is more complex than kineses or taxes}

•

Movements of animals may depend on

internal maps

– _{Cognitive maps}

• _{internal representations of spatial relationships of}

objects in the surroundings

Learning #3

1

2

3

Nest

No nest

No nest Nest

Nest

Learning #4 Associative learning

– _{An animal learns that a particular stimulus or a}

particular response is linked to a reward or punishment

– _Classical

conditioning-• _{An arbitrary stimulus is associated with a response}

• _{http://www.snotr.com/video/183}

– _{Operant conditioning}

• _{Trial and error}

• _{Skinner Box:}

Learning #5 Social learning

• _{Social learning involves observation and imitation of}

others

– _{Social learning involves changes in behavior that} result from the observation and imitation of others

– _{http://au.news.yahoo.com/world/a/-/world/1009475}

7/Orangutan-washing-itself-with-towel-wows-the-We b/

Learning #6 Cognition and problem solving

•

Problem-solving behavior relies on cognition

system to perceive, store, process, and use information

The evolution of behavior: foraging

•

Foraging behavior

– _{Cost-benefit balance:}

• _Energy

• _{Risk of predation}

The evolution of behavior: mating systems

•

Mating behaviors enhance reproductive

success:

– _{Promiscuous, monogamous, or polygamous}

(polygyny and polyandry)

– _{Which do you think is more common and why?}

•

What influences mating systems?

– _{Needs of young}

– _{Certainty of paternity}

The evolution of mating behavior: Mate

choice

• _{Intersexual selection}

– _{Usually females are the}

choosy sex

– _{Influences male behavior}

• _{Intrasexual selection}

– _{Usually males compete}

with one another

– _{Again, influences male}

behavior and anatomy

http://www.youtube.com/w atch?NR=1&feature=endscre en&v=8W7qk5Zncj0

– _{http://www.youtube.com/}

SOCIAL BEHAVIOR AND SOCIOBIOLOGY

•

Sociobiology studies social behavior

– _{The interactions of two or more} animals, in an evolutionary sense

• _{Altruism: behavior that reduces an individual’s}

fitness while increasing the fitness of others in the population

– _{Altruism can usually be explained by}

inclusive fitness and kin selection- maybe…

• _{An animal can propagate its own genes by}

Overview

1. Limiting factors in distribution of species

– _{Biotic and abiotic factors}

What limits species distribution?

1. Vagility- the ability to disperse (transplant exp)

2. Behavior- habitat selection

3. Biotic features

– _{Organisms that eat limit the distribution of those}

that get eaten

4. Abiotic features

– _Temperature

– _Water

– _Sunlight

– _Wind

– _{Rocks and soil}

Climate

•

Macroclimate

•

Global, regional, local

•

Microclimate

Macroclimate

• _{Influenced by :}

– _{Bodies of water} – _Topography

(mountains)

– _Seasonality

• _{Global Climate}

Patterns

– _{Latitudinal effects}

on sunlight intensity

– _{Air circulation and}

precipitation patterns

Low angle of incoming sunlight

Sunlight strikes most directly

General Features of Terrestrial Biomes

•

Terrestrial biomes are often named for major

physical or climatic factors and for vegetation

•

Terrestrial biomes usually grade into each other,

without sharp boundaries

– _{The area of intergradation is called an ecotone}

– _{So why do we discuss things as if there were sharp}

And now, for the game show craze sweeping

the nation!!!!

How m

any b

iomes

can Y

OU na

Biome map

Terrestrial Biome quiz

Chapter 52

Overview

•

What is population ecology?

•

Dispersal

•

Demography

•

Population growth curves

•

Limits to growth

1. Density and Dispersion

• _{Density is the number of individuals per unit area or}

volume: additions and subtractions

– _{Determining the density of natural populations is difficult}

(WHY???)

• _Sampling

• _{Mark/Recapture} • Index

• _{Dispersion is the pattern of spacing among individuals}

Patterns of Dispersion

•

Environmental and social

factors influence spacing

– _{Patch quality}

•

Patterns:

– _{Clumped (the most}

common pattern)

– _{Uniform: evenly spaced}

– _{Random: no pattern}

2. Demography

•

Demography is the study of the vital statistics

(e.g. death rates and birth rates) of a population

and how they change over time

•

A life table is an age-specific summary of the

survival pattern of a population

– _{It is best made by following the fate of a cohort}

•

Life tables predict an individual’s statistical

chance of dying during each interval of the

individual’s lifetime

Reproductive Rates

• _{A reproductive table (fertility schedule): an age-specific}

summary of the reproductive rates in a population

Age Prop w/litter Mean litter

size Mean # Fs in litter Avg # female kids

0-1 0 0 0

1-2 0.65 3.3 1.65

2-3 0.92 4.05 2.03

3-4 0.90 4.9 2.45

4-5 0.95 5.45 2.73

5-6 1 4.15 2.08

6-7 1 3.4 1.7

7-8 1 3.85 1.93

8-9 1 3.85 1.93

– _{A survivorship curve is a graphic way of}

representing the data in a life table end G

• _{The three types of survivorship curves reflect species’}

differences in reproduction and mortality

P er ce n ta ge o f s ur vi vo rs ( lo g sc a le ) 100 10 1 0.1 0 5 0 10 0 III II I

Percentage of maximum life span

Life History Diversity

•

Semelparity: one shot at reproduction

3. Models of population growth:

exponential growth

•

Scientists still model the capacity for population

increase in the absence of limiting factors

– _{If immigration and emigration are ignored, a}

population’s growth rate (per capita increase) equals birth rate minus death rate

• _{In 36 hrs, one e. coli can produce enough descendents to layer the}

• _{This equation can be written without calculus:} • _{ΔN/ Δt= rN}

– _{r is the per capita rate of increase (per capita births minus per}

capita deaths)

– Under ideal conditions, r_max is the intrinsic rate of growth

• _{This basically says: change in population size during a given}

time interval is equal to the “intrinsic rate of increase” (r) times the population size at the start of the time interval (N)

Models of population growth: logistic growth

• _{Exponential growth cannot be sustained for long in}

any population

• _{A more realistic population model limits growth by}

incorporating carrying capacity (K); the maximum population size the environment can support

• _{the per capita rate of increase declines as carrying}

capacity is reached

– _{Start with the exponential model}

– _{Add an expression that reduces r (per capita rate of}

increase) as N increases

dN

dt

=

(

K-N

•

The logistic growth equation includes

K

, the

carrying capacity

Number of generations

P o p u la ti o n s iz e ( N )

K = 1,500 1,500 2,000 1,000 500 15 10 5 0 0 Logistic growth Exponential growth = 1.0N

dN dt

= 1.0N dN

dt

1,500 – N

1,500 Time (days) N u m b er o f P ar am ec iu m /m L 1,000 0 400 5 200 10 0 15 800 600

•

Some populations overshoot

K

before settling

down to a relatively stable density

Time (days) N u m b er o f D ap h n ia /5 0 m L 180 0 90 20 60 40 0 60 150 120

A Daphnia population in the lab 30

The Logistic Model and Life Histories

•

Life history traits favored by natural selection may

vary with population density and environmental

conditions

•

K

-selection, or density-dependent selection,

selects for life history traits that are sensitive to

population density- stable environments

•

r

-selection, or density-independent selection,

4. Population Change and Population Density

•

In density-independent populations, birth rate and

death rate do not change with population density

•

In density-dependent populations, birth rates fall

and death rates rise with population density

•

Why might death rates tend to rise at higher

Density-Dependent Population Regulation

• _{Density-dependent birth and death rates are an}

example of negative feedback

• _{They are affected by many factors, such as:}

1. Competition for resources 2. Territoriality

3. Health

Stability and Fluctuation

•

Long-term population studies have challenged the

hypothesis that populations of large mammals are

relatively stable over time

1960 Year M o o se p o p u la ti o n s iz e 2,500

Steady decline probably caused largely by wolf predation 2,000 1,500 1,000 500 0

1970 1980 1990 2000

Metapopulations and Immigration

•

Metapopulations

are groups of populations

• _{Many populations}

undergo boom-and-bust cycles

• _{Boom-and-bust cycles}

are influenced by

complex interactions between biotic and abiotic factors Year H a re p o p u la ti o n s iz e (t h o u s an d s ) 1850 Snowshoe hare 0

LE 52-22 8000 B.C. H u m an p o p u la ti o n ( b il li o n s) 6 5 4 3 2 1 0 4000

B.C. 3000B.C. 2000B.C. 1000B.C.

The Plague

0 1000

Chapter 53

Continuing our jaunt through

ecology…

Overview: What Is a Community?

Interspecific interactions 1. Competition

• _{Interspecific competition: species compete for a limited}

resource

– _{Strong competition can lead to competitive exclusion}

– _{The competitive exclusion principle : two species competing}

for the same limiting resources cannot coexist

• _{Ecological niche: the total of a species’ use of biotic and}

abiotic resources

– _{As a result of competition, a species’ fundamental niche may}

Results of competition

• _{Resource partitioning is differentiation of ecological}

niches, enabling similar species to coexist in a community

• _{Character displacement: characteristics are more}

divergent in sympatric populations of two species than in allopatric populations of the same two species

Beak depth

Sympatric populations

G. fuliginosa G. fortis

Santa María, San Cristóbal 40 20 0 Los Hermanos 40 20 0 Daphne 40 20 0 G. fuliginosa, allopatric G. fortis, allopatric Beak depth (mm)

Interspecific interactions 2. Predation

•

An interaction where the predator, kills and eats

the prey end A

•

Feeding adaptations of predators: claws, teeth,

fangs, stingers, and poison

•

Prey display various defensive adaptations

– _{Behavioral defenses}

– _{Morphological and physiological defense adaptations}

LE 53-7

Batesian Mimicry- one is harmless

Predation con’t: Herbivory

•

Herbivory refers to an interaction in which an

herbivore eats parts of a plant or alga

•

It has led to evolution of plant mechanical and

Interspecific interactions 3A. Parasitism

•

In parasitism, the parasite derives nourishment

from its host, which is harmed in the process

Interspecific interactions 3B. Disease

•

Effects of disease on populations and

communities are similar to those of parasites

•

Pathogens, disease-causing agents, are typically

Interspecific interactions 3C. Mutualism

•

Mutualistic symbiosis, or mutualism, is an

Interspecific interactions 3D. Commensalism

•

In commensalism, one species benefits and the

Interspecific Interactions and Adaptation

•

Coevolution is reciprocal evolutionary

Overview…

•

Community structure!

– _{How many species}

• _{How to measure it} • _{What affects it}

– Location

– Size

– _{Trophic relationships}

•

Species that impact community structure

•

Succession

Species Diversity

•

Species diversity of a community is the variety

of organisms that make up the community

•

It has two components:

1. species richness: the total number of different species in the community

2. relative abundance: the proportion each species represents of the total individuals in the

Community 1 A B

C

D

A: 25% B: 25% C: 25% D: 25%

Community 2

A: 80% B: 5% C: 5% D: 10%

• _{A community with an even species abundance is}

considered more diverse than one in which one or two species are abundant and the remainder are rare

Trees T re e s p ec ie s ri c h n es s 180 160 140 120 100 80 0 V er te b ra te s p ec ie s ri ch n es s (l o g s ca le ) 200 100 50 10 60 40 20 1,100 900 700 500 300 100

Actual evapotranspiration (mm/yr)

Vertebrates

2,000 Potential evapotranspiration (mm/yr)

1,500 1,000

500

•

Two main climatic factors

correlated with biodiversity

are solar energy and water

availability

– _{Evapotranspiration is}

evaporation of water from soil plus transpiration of water

from plants

– _{http://micrometeorology.unl.}

What influences diversity? Area Effects

•

The species-area curve : all other factors being

equal, a larger geographic area has more species

•

A species-area curve :

N u m b er o f sp ec ie s (l o g s ca le )1,000 Area (acres) 1010 109

106 ₁₀7 ₁₀8

103 104 ₁₀5

1 10 100 100

10

Island Equilibrium Model

•

Species richness on islands depends on island size,

distance from the mainland, immigration, and

extinction (WHY??)

•

The equilibrium model of island biogeography

maintains that species richness on an ecological

island levels off at a dynamic equilibrium point

Area of island (mi2)

Trophic Structure

•

Trophic structure is

the feeding

relationships between

organisms in a

community

•

Food chains link

trophic levels from

producers to top

carnivores

Food Webs

•

A food web is a branching food chain with

Limits on Food Chain Length

•

Each food chain in a food web is usually only a

few links long

•

Two hypotheses attempt to explain food chain

length:

1. The energetic hypothesis

• Length is limited by inefficient energy transfer (more on this later) Why might this be?

2. The dynamic stability hypothesis

Species with a Large Impact #1

1. Dominant species are those that are most

abundant or have the highest biomass

– _{Are they most competitive in exploiting resources?}

Species with a Large Impact #2

2. Keystone species are not necessarily

abundant in a

community :They exert strong control on a

community by their ecological roles, or niches

Without Pisaster (experimental)

With Pisaster (control)

Species with a Large Impact #3

•

Ecosystem “Engineers” (Foundation Species)

exert

influence by causing physical changes in the

environment that affect community structure

•

For example, beaver dams can transform

Bottom-Up and Top-Down Controls

• _{The top-down model proposes that control comes}

from the trophic level above

– _{Trophic cascade}

– _{In this case, predators control herbivores, which in turn}

control primary producers

• _{Bottom up model: control comes from producers}

• _{Long-term experimental studies have shown that}

Disturbance influences species diversity and composition

• _{Decades ago: Communities are in a state of equilibrium}

• _{Now: nonequilibrium model- communities constantly}

changing after being buffeted by disturbances

• _{Intermediate disturbance hypothesis: moderate levels}

Ecological Succession

•

Ecological succession is the sequence of community

and ecosystem changes after a disturbance

•

Primary succession occurs where no soil exists when

succession begins

•

Secondary succession begins in an area where soil

remains after a disturbance

•

http://environmentalet.hypermart.net/digiweb/seco

ndarysuccession.html

•

Early-arriving species and later-arriving species

may be linked in one of three processes:

– _{Early arrivals may facilitate appearance of later}

species by making the environment favorable

– _{They may inhibit establishment of later species}

– _{They may tolerate later species but have no impact}

Chapter 54

Overview: Ecosystems, Energy, and Matter

•

An ecosystem consists of all the organisms living in

a community, as well as the abiotic factors with

which they interact

•

Energy and nutrients pass from primary producers

(

autotrophs

) to primary consumers (

herbivores

)

and then to secondary consumers (

carnivores

)

•

Energy flows

through an ecosystem, entering as

light and exiting as heat

LE 54-2

Microorganisms and other detritivores

Tertiary consumers

Secondary consumers

Detritus Primary consumers

Sun

Primary producers

Heat

Key

Primary production

•

Primary production

: the amount of light energy

converted to chemical energy by autotrophs

during a given time period

•

Total primary production is known as the

ecosystem’s gross primary production (GPP)

•

Net primary production (NPP) is GPP minus energy

used by producers

– _{Only NPP is available to consumers}

•

Overall, terrestrial ecosystems contribute about

two-thirds of global NPP

Atlantic Ocean Shinnecock Bay Moriches Bay 2 4 5 30 11 15 19 21

Coast of Long Island, New York

Phytoplankton

Inorganic phosphorus

Great

South Bay MorichesBay

Shinnecock Bay Station number 21 19 15 30 11 5 4 2 8 5 4 3 2 1 0 6 7 8 5 4 3 2 1 0 6 7

Phytoplankton biomass and phosphorus concentration

P h y to p la n k to n (m il lio n s o f ce lls /m L ) In o rg an ic p h o s p h o ru s (µ m a to m s/ L ) Ammonium enriched

Station number5 11 30 15 19 21 4 2 30 P h y to p la n kt o n (m il lio n s o f ce ll s p er m L ) Starting algal density

Phytoplankton response to nutrient enrichment

24 18 12 6 0 Phosphate enriched Unenriched control

•

In marine and

freshwater ecosystems,

both light and nutrients

control primary

production

•

Light Limitation:

Depth

of light penetration

affects primary

production

•

Nutrient Limitation:

More than light,

Primary Production in Terrestrial and Wetland

Ecosystems

• _{In terrestrial and wetland ecosystems, climatic factors}

affect primary production; soil nutrients have local effects

– _{Actual evapotranspiration is the water annually transpired by}

plants; it is related to net primary production

Mountain coniferous forest Temperate forest Tropical forest Temperate grassland Arctic tundra Desert shrubland 1,500 1,000 500 0 0 1,000 2,000 3,000

Actual evapotranspiration (mm/yr)

Secondary production

•

Secondary production

of an ecosystem is the

amount of chemical energy in food converted to

new biomass

– _{An organism’s production efficiency is the fraction of}

energy stored in food that is not used for respiration

Growth (new biomass)

Cellular respiration

Feces 100 J _{33 J}

67 J 200 J

Trophic Efficiency

• _{Trophic efficiency is the percentage of production}

transferred from one trophic level to the next

– _{It usually ranges from 5% to 20%}

1,000,000 J of sunlight 10,000 J

1,000 J 100 J 10 J Tertiary

consumers Secondary consumers

Primary consumers

NUTRIENT CYCLING: Decomposition

•

Decomposition connects all trophic levels

•

Detritivores, mainly bacteria and fungi, recycle

A General Model of Chemical Cycling

•

Carbon, oxygen,

sulfur, and nitrogen

are atmospheric and

cycle globally

•

Less mobile elements

such as phosphorus,

potassium, and

calcium cycle on a

more local level

•

All elements cycle

between organic and

inorganic reservoirs

Fossilization

Reservoir a Reservoir b

Reservoir c Reservoir d

Organic materials available as nutrients Organic materials unavailable as nutrients Inorganic materials available as nutrients Inorganic materials unavailable as nutrients Living organisms, detritus Coal, oil, peat Atmosphere, soil, water Minerals in rocks Assimilation, photosynthesis _Burning

of fossil fuels

Water, Carbon, Nitrogen. Phosphorus

•

Make cycle diagrams using books/internet

•

Note whether each item you include is a process

or a reservoir

•

Note whether each reservoir is inorganic or

organic

•

Note which processes/reservoirs are MAJOR or

minor players in the cycle

•

Write down two or more ways in which humans

impact that cycle

•

http://www.phschool.com/science/biology_pl

LE 54-17a

Transport over land

Precipitation over land Evaporation

from ocean Precipitation

over ocean

Net movement of water vapor by wind

Solar energy

Evapotranspiration from land

Runoff and groundwater

LE 54-17b

Cellular respiration

Burning of fossil fuels and wood

Carbon compounds in water

Photosynthesis

Primary consumers

Higher-level consumers

Detritus

Decomposition

LE 54-17c

Assimilation

N₂ in atmosphere

Decomposers

Nitrifying bacteria

Nitrifying bacteria Nitrogen-fixing

soil bacteria

Denitrifying bacteria

Nitrification Ammonification

Nitrogen-fixing bacteria in root nodules of legumes

NO₃–

NO₂–

NH₄+

LE 54-17d

Sedimentation

Plants Rain

Runoff Weathering

of rocks Geologic

uplift

Soil Leaching

Decomposition Plant uptake of PO₄3–

Decomposition and Nutrient Cycling Rates

• _Decomposers

(detritivores) play a key role in the general pattern of chemical cycling

• _{Rates at which nutrients}

cycle in different

ecosystems vary greatly, mostly as a result of

differing rates of decomposition

Nutrients available to producers

Decomposers

Geologic processes

Abiotic reservoir Consumers

Contamination of Aquatic Ecosystems

•

Critical load for a nutrient is the amount that plants

can absorb without damaging the ecosystem

•

Remaining nutrients can contaminate groundwater

and freshwater and marine ecosystems

Toxins in the Environment

•

Humans release many

toxic chemicals that may

persist in environment

•

In biological

magnification, toxins

concentrate at higher

trophic levels, where

biomass is lower

Rising Atmospheric CO₂

•

Due to the burning of fossil fuels and other

human activities, the concentration of

atmospheric CO

has been steadily increasing

•

The FACTS-I experiment is testing how elevated

CO

influences tree growth, carbon