Exam 3 eco

Trophic

energy/food web/energy transfer

Autotrophs (auto=self)

use inorganic sources of carbon and energy (eat/fungi and stuff I thunk) photosynthetic/chemosynthetic (chem use other sources than carbon)

Photosynthetic

use CO2 as carbon source and sunlight as energy

chemosynthetic

us organic molecules (sugars) as carbon source and inorganic molecules for energy

Heterotrophs

use organic molecules (sugars) as sources for carbon and energy (they eat living things. animal/fungi)

CHONps

organic=CHON

inorganic=ps I thunk

(CHON=93-97% of biomass of plants, animals, fungi, and bacteria)

(C:N is higher in plants than in herbivores)

producers

all plants/some protist/some prokaryotes (chemo)

prokaryotes

have more tropic diversity than any other group

marine prokaryotes can photosynthesis using Rhodopsin (light sensitive is adapted to local variations in light quality)

eutrophication

a body of water becomes enriched with excess nutrients, leading to excessive growth of algae and plants and often resulting in oxygen depletion and ecological disruption.

biomagnification

higher you go up the food web the more magnified the bad effects are (an eagle eats a fish that has already eaten some things with toxin)

photosynthetic pathways

-absorb light and transfer energy electrons during PS

-energy is then used to synthesize ATP and NADH which is then later used to make sugar

three photosynthetic pathways

C3 PS=the normal photosynthesis 95% (most plants all algae)

C4 photosynthesis (corn and soybeans) (they use spatial separation) (light and carbon reactions happen in 2 different cells/PS happens in 2 different cells)

CAM photosynthesis (temporal separation) (they wait to do the carbon reactions at night) (stromata closed at daytime) (used by plants in arid environments)

C3 PS pathway

Used by most plants BUT ALL algae

red algae=Worst at PS

green algae=Best at PS

rubisco is not important for us eco students

chemosynthetic autotrophs

chemosynthetic bacteria commonly use sulfur instead of carbon

detritivores (fungi)

feed on non-living organic matter (usually plant remains)(once living organic matter)

Ecological stoichiometry

concerns the balance of multiple chemical elements in ecological interactions, for example, the balance of multiple chemical elements between plants and the herbivores that consume them.

because of the imbalance (10% rule) consumers have to eat more to obtain limiting nutrients

10% rule

when something eats something, they only get 10% of the nutrients/energy I thunk

Essential nutrients

plants: get most of theirs through soil via roots

Animals: get theirs through the food they eat

plant water and sugar flow

Xylem=go up= water

Phloem=down= sugars

Herbivore nutritional chemistry problems

must compensate for large difference between food nutrient content and animal growth requirements

Must overcome plant physical and chemical defense (thorns, silica, cellulose, lignin)

Toxins (digesting-reducing substances)(reduce N)

damselfish case study

damselfish males defend territories

bluehead wrasse case study

territorial male bluehead wrasse protect harems of females while

“streaker” males sneak in for mating

snaoooing shrimp

snapping shrimp live in cooperative colonies

behavioral ecology

study of social relations

(relationships between organisms and the environment are mediated by behavior)

(influenced by social interactions)

Sociobiology

concerned with study of social relations

(sominance, mating interactions, cooperations and others)

(influenced by social interactions)

Fitness

the number of offspring or genes contributed by an individual to future generations

(influenced by social relations)

plants reproduce

they reproduce sexually

many can also create clones (asexual) of themselves

timing

strongly influenced reproductive systems

anthropomorphic view (humans put their own view on things like bias to sexual reproduction I guess)

because asexual reproduction is common in other organismal groups

what is male, what is female

male is at least 1 Y chromosome

Women are just X chromosomes

female vs male gametes

Females produce larger, more energetically costly gametes.

• may be limited by resource access

Males produce smaller, less costly gametes

• may be limited by mate access

sexual selection

difference in reproductive rates among individuals from difference in mating success

intrasexual selection vs intersexual selection

intrasexual selection: individuals of one sex compete for mates

Intersexual selection: predators

mate choice and sexual selection in guppies

given a choice female guppies will mate with brightly colored males (reflects male genetics and health)

brightly colored males also attract predators

Tradeoff between higher mating success and vulnerability to predators

(populations with less predators= more brightly colored guppies/fish)

Endlers experimental test on natural selection study to test color pattern in guppies

greenhouse and feild experiments

when freed from predation average number of spots on male guppies increased

(predation moderates the effects of intersexual selection by female guppies)

adult scorpion flies (genus panorpa) case study (thronhill)

-feed on dead arthropods in the forest

understory.

• dead arthropod supplies are often limited

• Thornhill found that male Panorpa will guard dead arthropods

-Males attract females to mate with nuptial gifts

• offering a dead arthropod as a food source

• secreting a mass of saliva

(females more attracted to guys who can bring bigger dead arthropods)

cash

hoarding behavior like squirrels storing acorns

nuptial gifts

animals give gifts in return for hopes of reproduction I guess (covered in spit too)

sociality

relationships among individuals change when they begin living in groups and cooperating with each other

(simple acts such as mutual grooming and defense)

Eusociality

complex behaviors of stratified societies + normal sociality

multi-generation groups

cooperative care of the young

division into reproductive and nonreproductive castes

(like bees)(roles are defined at the genetic level)

larval stage/immature

just mean nonproductive stage of life

reproductive castes

like roles

queen

drones

workers

(genetically influenced/always reinforced by hormones)

Restricted reproduction (social roles)

not all reproduce but they help someone reproduce (like how not all bees have sex but the queen and drones do)

inclusive fitness

improve survival and reproductive rates of family members

Kin selection: evolutionary force favoring this behavior

ligon and ligon green woodhoopoes (pheniculus purpureus ) (Case Study)

- one pair in the flock breeds, the rest = helpers

Exhibit strong Philopatry (they stay in the area they were born their whole life), with limited dispersal from natal territory (where they are born)

• Likely due to scarcity of roost cavities (roost = where they sleep/more permeant home, but nest is just associated with breeding) (roost take no energy they just find a spot)

Reproductive success affected by rainfall, territory quality

- The helpers increase their inclusive fitness

- Delayed reproduction increases lifetime reproduction success

clutch size

the amount of offspring/eggs/liter

packer and pusey studied cooperation among African lions (Panthera leo) (Case Study)

females usually live in prides of 3-6 adults, dependents offspring and some adult males

-females are usally related, males vary

Lions exhibit many forms of cooperation

• shared nursing of cubs

• cooperative hunting and defense

• female cooperation due to kin selection

Eusocial case study wit ants annd mole rats

Leaf-cutter ants are socially complex

• important consumers in tropical systems

• use leaf fragments to FARM fungi

• nests can have 1,000 entrances, 2,000 chambers and 5-8 million

workers

Naked mole rats also live underground

• colonies of usually 70-80 (up to 250)

• burrow system can cover 100,000m2

• like ants, they live in a caste system

light waves

longer wave lengths=less energy=infrared light

shorter wave lengths=more energy=ultraviolet light

Photosynthetically active radiation=visible light between the 2 extremes (PAR) (this is the light photosynthesis uses)

Aposematic coloring

Prey with bright coloring as a warning

Mullerian mimicry

mimicry among several species of noxious organisms

Batesian mimicry

Harmless mimics

energy limitation

internal constraints on processing time limits the rate organisms can take in energy

functional response

as food increases, animals rate of feeding increases then falls off

holling defined 3 functional responses

1: feeding rate increases linearly with food density; levels off at maximum (requires little/no time to process)

2: rate rises linearly at low food density; slowly at intermediate and levels off at high food density

3: feeding rate increases most rapidly at intermediate densities

(type 2 response is most common)

Photon flux and photosynthetic response curve

rate of photosynthesis

• increases linearly with photon flux at low light intensities

• rises more slowly with medium light

• tends to level off at high light intensities

response curves for different species generally level off at different MAX PS rates

Optimaal forging theory

-Based on the prediction that natural selection will favor organisms

that are more effective at acquiring energy

- Assumes if energy supplies are limited, organisms cannot maximize

all of life’s functions simultaneously

-compromise between competing resource demands and the

principle of (energy) allocation

-Attempts to predict what/when/where organisms feed

A model for diet breadth (measurement)

rate of energy intake by predator is E/T (energy over time)

Predators will continue to add different types of prey to diet until the rate of energy intake reaches a maximum - optimization

Optimal foraging by plants

-Plants forage by growing and orienting nutrient/energy capturing structures

leaves?!

limited supplies of energy for allocation to leaves, stems and roots

-Appear to allocate growth in manner that increases acquisition of resources in

shortest supply

Applications: bioremediation using the diversity of bacteria to solve environmental problems

-gas and other petroleum products stored in underground tanks are a pollution source

-Some bacteria can be used to clean up contaminated soils and aquifers

-naturally occurring populations can break down benzene

Cyanide and nitrates in mine spoils

-cyanide is used to leach gold from ore

some bacteria can break down cyanide into NH3 which is converted to

nitrate

this mining technique contaminates soils with both CN- and nitrate

-Studies found leached ores contained rich nitrogen but little organic

carbon

supplementing ores with sucrose to increase carbon allowed bacteria to breakdown CN- and stimulated nitrate use

Hermaphrodites (often plants)

combine male and female function in a single individual

Male cooperation in African lions

-Cooperation within male coalitions does NOT always involve

close relatives

• single males have no chance of claiming/defending pride

• must form coalitions with other males

These patterns show clearly that males that team up with unrelated individuals mostly do so in coalitions of two or three.

-Probability of siring young depends on rank and coalition size

• reproductive success is more variable for males in coalitions of 3- 4 (than groups of 2)

• larger coalitions are more likely to contain male relatives

Caste division of labor ant vs mole rat

 Leaf-cutter ants:

• division of labor based mainly on size

• much size variation; many castes

• one female breeder mates with male drones

- sterile females are workers; winged females and reproductive males leave

colony after they are born

 Naked mole rats:

• one female breeder with a few males

- other males are nonreproductive workers – they fit one of two size categories

- large workers are for defense; smaller workers do all other work in colony

Tinbergen’s Framework

• understanding a behavior requires knowing:

- mechanistic causes of behavior (causation)

- how development influences behavior (ontogeny)

- evolutionary history of behavior (phylogeny)

- how behavior functionally contributes to fitness (adaptation)

Most reintroductions of captive-bred animals fail

possibly due to their behavior

Increasing complexity of captive environment, environmental

enrichment, may help captive animals retain critical behaviors

Was found to help captive-bred Atlantic cod (Gadus morhua)

• a more variable hatchery environment led to behaviors that would

increase chance of survival in the wild

Populations can be characterized by

• distribution – the size, shape and location of the area occupied

• pattern of spacing

• number of individuals (abundance)

• density

• age distributions, growth rates, etc

Distribution limits

The environment limits the geographic distribution of a

species.

• organisms can only compensate so much for environmental

variation

• compensation (i.e. regulating body temperature, water

content, etc.)

No single species can tolerate the full range of

environments.

Niche

Summarizes environmental factors that influence growth, survival and reproduction of a species.

A niche consists of ALL FACTORS necessary for the

existence of a species.

Niche concept developed independently by Grinnell and Elton

• Grinnell focused on effects of the physical environment

• Elton included biotic and abiotic factors

Hutchinson’s niche

Hutchinson defined niche as an n-dimensional hyper-volume

• n is the number of environmental factors important to survival and

reproduction

Fundamental niche – the hypervolume; the physical conditions under

which an organism CAN live

Realized niche – the restricted conditions under which an organism

DOES live due to interactions with other organisms

Kangaroo distributions and climate

Caughley, et al., found a close relationship between climate and distribution of the three largest kangaroos in Australia

• Eastern grey (Macropus giganteus) in the eastern 1/3 of the continent

• Western grey (M. fuliginous) in southern and western regions

• Red (M. rufus) in arid/semiarid interior aka the “outback” or the “bush”

• Northern Australia is too hot, too wet and/or too dry in winter for these three species

Climate and distributions

Limited distributions may be indirectly determined by climate because of

• food production

• water supply

• habitat

• incidence of parasites, pathogens and competitors

Relationship between climate and species distribution can be stable

for hundreds to thousands of years

Distributions of plants: moisture-temperature gradient

Encelia leaf pubescence corresponds to distribution on a moisture-

temperature gradient

Encelia frutescens has little pubescence while E. farinosa has pubescence and therefore absorbs less radiant energy.

•both live in hot deserts and have similar leaf temps

•E. frutescens avoids overheating via evaporative cooling

•E. frutescens also occupies cooler microclimates

Distribution of barnacles along an intertidal exposure

gradient

Organisms living in an intertidal zone have evolved different degrees of

resistance to drying.

Barnacles show distinctive patterns of ZONATION within the intertidal

zone.

• Connell found Chthamalus stellatus restricted to upper levels while

Balanus balanoides is limited to lower levels

Abiotic and biotic influences on distribution

Both abiotic and biotic factors are important in determining the

distribution and abundance of a species,

Balanus appears to be more vulnerable to desiccation excluding it from

the upper intertidal zone

• Chthamalus adults appear to be excluded from lower areas due to

competition with Balanus

• what else (besides competition) can influence the stratification of a habitat?

archaea

The archaea are prokaryotes distinguished from bacteria on the basis of structural, physiological, and other biological features. Though first discovered in association with extreme environments, the archaea are now known to be widely spread in the biosphere.

bundle sheath

A bundle sheath forms a protective interface between vascular tissue and the mesophyll. It prevents air entry into xylem, regulates water loss, and supports photosynthesis. (especially important in C4 plants)

irradiance

the amount of light or other radiant energy hitting a surface per unit area, measured in watts per square meter

Photon flux density

is the number of photons striking a square meter surface each second.

photorespiration

is a process in plants where oxygen is used instead of carbon dioxide, wasting energy and reducing sugar production.

principle of allocation

allocation of energy to one function, such as growth or reproduction, reduces the amount of energy available to other functions, such as defense. As a consequence, there must be compromises between competing demands.

rhodopsin

light-absorbing pigments found in animal eyes and in the bacteria and archaea.

C4 and CAM plants

are more efficient in their use of water than are C3 plants.

Birds and other predators exert strong selective pressure on populations of peppered moths

based on the extent to which they are camouflaged. When trees were covered with soot due to industrialization, darker morphs were more abundant, whereas in the wake of environmental regulations that reduced air pollution, the bark of trees became light-colored again, resulting in dramatic shifts in the frequency of the lighter morph.

Robin Bolser and Mark Hay (1996) tested the hypothesis that tropical seaweeds have more chemical defenses than temperate seaweeds.

The results of this study showed a clear preference for temperate species of seaweed

When given a choice the urchins removed approximately twice as much of the available temperate seaweed.

tropical seaweeds have more potent chemical defenses.

Green and colleagues

discovered that the lionfish had capture rates that were much higher than the native species tested.

This is likely because the prey species had evolved defense strategies that were effective against the historical predators

Augustin Iriarte and his colleagues (1990)

found that as pumas increase in size, the average size of their prey also increases

Shannon Murphy, Danny Lewis, and Gina Wimp studied the impacts of size by asking if the diets of wolf spiders changed as they aged

Using nitrogen isotope analysis of field-collected spiders, they were able to determine that diet did change: young spiders primarily hunted detritovores, whereas the larger, older wolf spiders were hunting herbivores

all case studies testing functional response in animals

everything ends up with the type 2 response

Foraging by Bluegill Sunfish

The optimal diet matches well with the actual diets of bluegills in Lawrence Lake. A similar match was obtained for bluegills feeding on zooplankton in open water.

Werner and Mittelbach found that optimal foraging theory provides reasonable predictions of prey selection by natural populations of bluegills.

plant forging case studies

plants try to get everything at an equal need

many plants modify their anatomy to match environmental circumstance in the direction predicted by economic theory.

haplodiploidy

denoting or possessing a genetic system in which females develop from fertilized (diploid) eggs and males from unfertilized (haploid) ones.

pistil

female organ of a flower.

self-incompatibility

incapacity of a plant to fertilize itself

stamen

male organ of a flower.

Evolution of sociality

driven by the need for group defense of high-quality territories and/or defense of mates and young.

Plants can exhibit nonrandom mating and sexual selection.

female mate choice can occur by differentially allowing certain pollen donors to fertilize eggs or by favoring some seeds over others.

Marshall performed dozens of experiments on wild radish mating systems that showed not only nonrandom mating likely due to competition between males, but also evidence of female choice

Meerkats, Suricata suricatta

cooperatively breeding groups of up to 30 individuals. Within a group of meerkats, commonly called a “mob,” a dominant female and a dominant male produce most of the young, with other adults sharing in guarding and defending the mob and caring for pups.

random distribution

individuals within a population have an equal chance of living anywhere within an area

regular distribution/even distribution (territorial)

individuals are uniformly spaced