Bio 2 Exam 4 Flashcards
What is ecology?
Study of interactions among organisms and their environment
What is a biotic interaction?
Interactions among living things
What are abiotic interactions?
Between organisms and their nonliving environment
What do biotic and abiotic interactions govern?
The number of species in and area and their population densities
What are the scales of ecology?
starts at organismal ecology, population ecology, community ecology, and ends at ecosystems ecology
What does hypothesis testing involve?
- observations
- hypothesis formation
- experimentation
- data analysis
- acceptance or rejection of hypothesis
What do graphs imply in hypothesis testing?
Imply correlation or meaningful relationship between 2 variables. CORRELATION DOES NOT MEAN CAUSATION
What is the impact of the environment?
Both geographic distribution pattern and abundance are limited by physical features of the environment
What are five important physical features of the environment?
- temperature
- wind
- water and light availability
- salinity
- pH
What is the impact of temperature?
Most important factor in the distribution of organisms (effects biological processes inability of most organisms to regulate body temperature precisely)
What is an example of the impact of temperature in the environment?
Coral reef organisms abundant only in warm water due to effects of temp on coral distribution.
— shell formation and coral deposition are accelerated at high temperatures but are suppressed in cold water
What is the second example of the impact of temperature on the environment?
Frost is the most important factor limiting geographic distribution of tropical and subtropical plants (ex. cactus distribution limited to places where temp does not go below freezing for more than one night)
What are two examples of the impact of high temperatues?
- corals expel symbiotic algae when temperatures are too high (coral bleaching)
- giant sequoias depend on fire to enhance seed release and clear out completing vegetation
What is the greenhouse effect?
Solar radiation passes through the atmosphere and heats the Earth’s surface —-> energy radiated from the Earth back into atmosphere —-> atmospheric gases (CO2, methane, water vapor) absorb the energy and reradiate to the Earth’s surface increasing temperature
What is global warming?
All greenhouse gases have increased in atmospheric concentrations since industrial times due to human activities
–As a result, anticipated changes in global climate will occur too rapidly for normal evolutionary processes to compensate
What is an example of global warming?
Climatic zones may shift faster than trees can migrate via seed dispersal resulting in extinction
What is the impact of pH?
- normal rainwater = pH of 5.6
- most plants grow best at pH 6.5 when nutrients are most available (pH less than 5.2 prevents nitrifying bacteria from working)
- chalk and limestone areas have a richer flora than acidic soils
- numbers of fish and other species decrease in acidic waters
What is acid rain?
- pH less than 5.6
- results from the burning fossil fuels containing sulfur dioxide and nitrogen oxide
What is behavioral ecology?
Studies how behavior contributes to the differential survival and reproduction of organisms
What is a fixed action pattern (FAP’s)?
Innate (instinctual) or genetically programmed behavior. Once initiated, will continue until completed
–ex. egg-rolling response in geese (improves fitness and increases survival of young)
What is a critical period?
Time when many animals develop species-specific patterns of behavior
–ex. imprinting - goslings follow the first moving thing as “mother”
What is habituation?
Simplest form of learning (non-associative learning where organism ignores repeated stimulus-decrease in response to stimulus due to repetition)
What is associative learning?
Association develops between stimulus and response
What are the two main types of associative learning?
- Classical conditioning
- Operant conditioning
What is classical conditioning?
Involuntary response becomes associated positively or negatively with a stimulus that did not originally elicit the response (ex. Pavlov’s dog salivates when a bell rings)
What is operant conditioning?
Animals behavior reinforced by a consequence (reward or punishment, also called trial-and-error learning)
—ex. birds will learn to avoid toxic butterflies
What is cognitive learning?
Ability to solve problems with conscious thought and without direct environment feedback
–ex. chimp. stacking boxes to reach bananas
–ex. ravens retrieving meat by pulling on a string
What is behavior often a mix of?
It is a mix of innate and learned ( ex. birds are genetically programmed to learn but they will sing the correct song only of correct song is heard)
What is population ecology?
Study of what factors affect population size and how these factors change over space and time
What is a population?
A group of interbreeding individuals occupying the same habitat at the same time
What is density?
Number of organisms in a given unit area. Population growth affects population density (ex. knowledge on density and growth can help make decisions about species management)
What are the three dispersion patterns?
- clumped (most common)
- uniform
- random (rarest)
What is a clumped dispersion pattern?
Resources tend to be clustered in nature. Social behavior may promote this pattern
What is a uniform dispersion pattern?
Competition may cause this pattern. May also result from social interactions (beavers have a fairly uniform rate of death over the life span)
What is a random dispersion pattern?
Resources are rarely randomly spaced may occur where resources are common and abundant
What are survivorship curves?
Plots numbers of surviving individuals at each age
What are the two life history strategies?
- r-selected species
- k-selected species
What are r-selected species?
High rate of per capita population growth, but poor competitive ability (weeds)
What are K-selected species?
More or less stable populations adapted to exist at or near carrying capacity
What is human population growth?
In 2006, the worlds population was estimated to be increasing at the rate of 146 people every minute
In what two ways can human populations exist at equilibrium densities?
- High birth and high death rates
- Low birth and low death rates
What are high birth and high death rates?
Before 1750, this was often the case, with high birth rates offset by deaths from wars, famines, and epidemics
What is low birth and low death rates?
- In Europe, beginning in the 18th century, better health and living conditions reduced the death rate
- eventually, social changes such as increasing education for women and marriage at a later age reduced the birth rate
What is a population pyramid?
Relative numbers of individuals in each defined age group –> helps predict future population growth
What is the Total Fertility Rate (TFR)?
Average number of live births a women has during her lifetime (2.3 = zero population growth)
What is carrying capacity?
The maximum population size of the species that the environment can sustain indefinitely, given the food, habitat, water and other necessities available in the environment
What is an ecological footprint?
Aggregate total of productive land needed for survival in a sustainable world (average footprint size is about 3 hectares - 1 ha = 10,000 m^2)
What are the four types of competition?
- intraspecific
- interspecific
- exploitation competition
- interference competition
What is intraspecific competition?
Between individuals of the same species
What is interspecific competition?
Between individuals of different species
What is exploitation competition?
Organisms compete indirectly through the consumption of a limited resource
What is interference competition?
Individuals interact directly with one another by physical force of intimidaiton
How can abiotic and biotic factors alter the outcome of competition?
- Competition between 2 species of flour beetles
- T. confusom usually won in the presence of parasite (biotic factor)
- temperature and moisture also impact competition (abiotic factor)
How can felid experiments impact species interactions?
Frequency of competition according to the number of species involved with a limited pool of resources (results in species assembling to use different components of resources eg. here seed size)
What is logistic growth?
Takes place when a population’s per capita growth rate decreases as population size approaches a maximum imposed by limited resources (called the carrying capacity K)
What is the competitive exclusion principle?
Complete competitors (with the same resource requirement) cannot coexist
What is resource partitioning?
Differentiation of niches, both in space and time, that enables similar species to coexist in a community —> bird species occupied different heights and portions in the tree and this each probably fed on a different range of insects
What is predation?
Classified according to how lethal they are for the prey and the length of association between consumer and prey
What are four antipredator strategies?
- aposematic coloration
- cryptic coloration
- batesian mimicry
- intimidation
What is aposematic coloration?
Warning coloration to signal the unprofitablity of prey (ex. some frogs)
What is cryptic coloration?
Camouflage
What is batesian mimicry?
False warning colorations (ex. some snakes)
What is intimidation?
Raised perceived threat (ex. puffer fish)
What is a predator-controlled system?
Action of predator feeding reduces supply of prey –> removal of predator results in increase in prey
What explains why every plant is not consumed?
- Predators and parasites keep herbivore numbers low
- plant anti-herbivore defenses make a difference
What is secondary metabolites?
Not part of primary energy generating metabolic pathway
What are mechanical defenses?
thorns and spikes
What are two examples of plant anti-herbivore defenses?
- Secondary metabolites
- mechanical defenses
What is parasitism?
One organism feeds off another, but does not normally kill it outright (ex. trematode life cycle)
What is an example of a parasitic flowering plant?
Rafflesia arnoldii - “corpse flower” parasite of vines
What is Anisakis simplex nematodes?
- eggs float in all oceans until they are eaten by crustaceans
- fish/squid eats the crustacean and the nematode develops into a cist in the muscle
- the fish then eaten by marine mammals (dolphins or seal) where the nematode reach adulthood in the gut
What is Anisakiasis in humans?
- Acute (short term effects of infection) form after digestion (abdominal pain, nausea and vomiting within hours. vomiting can dislodge the larvae from gastric mucosa)
- Chronic (long term effects of infection) form 1-2 weeks - the nematode larvae can attach themselves to the gastric mucosa or penetrate the stomach or intestinal wall, leading to abscess formation
What is Anisakiasis treatment and prevention?
- nematodes most common in cod, haddock, fluke, pacific salmon, herring, flounder, and monkfish (sushi, sashimi, other raw fish)
- prevention to kill anisakids = adequately cooking fish, freezing for seven days, or freezing for 15 hours
What is natural history?
Observations and knowledge about organisms and their environment
- ex. Dan Jansen used natural history observations to help restore the tropical dry forest of Guanacaste National Park (Costa Rica)
What is an example of why natural history is important to ecology?
- guanacaste tree Enterolobium cyclocarpum produces large and numerous fruit in order to promote seed dispersal by animals (now extinct horses, sloths, camels were original dispersers however Dan Janzen substituted cattle and horse as the new dispersers. As a result, also improved dispersal of other native plants)
Why are native plants of Costa Rica important?
- Native plants from the dry tropical forest of Costa Rica have a dispersal syndrome
- fruits and seeds have common-traits
- large sugar, oil, and nitrogen rich with hard seed coat to allow for passing intact through digestive track of large animals
Why is understanding natural history important?
Helps provide practical solutions to ecological problems
What is an example of herbivory (exploitative interactions)?
Cicadas nymphs feed underground on root xylem fluids (have strong digging forelimbs and long proboscis)
What are tymbal noise makers (cicadas)?
Fast moving muscles contract the tymbal causing ribs on tymbal plate to ripple
What are predators of cicadas?
Predatory wasps the catch adult cicadas to feed their young
What are periodical cicadas?
- nymphs emerge in large numbers at about the same time (sometimes more then 1.5 million individuals per acre)
Why do cicadas have a mass emergence?
-One hypothesis states that they are avoiding or satiating predators
—- Overwhelming their predators by their sheer numbers, ensuring the survival of most their members
- Another hypothesis is that mass emergence also creates a significant nutrients pulse
What are some examples of population dynamics?
Dispersal, metapopulations, survivorship curves, life tables
What are population dynamics?
Factors influencing expansion, decline, or maintenance of populations
What is dispersal?
Movement into (immigration) or out (emigration) of a population
- It can increase or decrease population density
What is an example of population dynamics?
- honeybees are not native to the new world
- European honey bees do well in north america, but not as well in tropical/subtropical south america
- in 1956, African honey bee were imported to Brazil to improve beekeeping in tropics
What was the goal of bringing over African Honeybees?
- Aimed to interbreed African and European bees to develop strain more suitable for the tropics (in 1957, nearly 30 colonies (swarms) were accidentally released and these bred with local bee populations)
- led to hybridization and naturalization of honey bees in Brazil
What are characteristics of African honey bees?
Open and exposed nests are common with high swarming rates and intense stinging behaviors
What was the effect of Africanized honey bees?
One of the most rapid population range expansions ever observed (300 km per year)
– in 30 years, range expanded to include most of South America and a large southern portion of North America
What is community ecology?
The factors that influence the number of species in a community
- ex. latitudinal gradient of species richness (number of species) of birds in North America
What is community stability?
Community is stable when little change can be detected in the richness and abundance over a given time-period
— A decrease in stability may indicate an ecological problem with the community
What is an example of community stability?
Diverse communities are seen as more stable because species vary in responses to changes in environmental conditions and a change in abundance of one species may compensate for a change in another
What is Succession?
Gradual and continuous change in species composition of a community following a disturbance –> endpoint called a climax community (stable)
What are the two types of succession?
- primary succession
- secondary succession
What is primary succession?
Succession in newly exposed site that has no biological legacy
– begins after lava flow of glacial retreat
What is secondary succession?
Succession on a site that supported life and has undergone a disturbance
– begins after disturbance like fire
What is ecosystem ecology?
System formed by the interaction between a community of organisms and its physical environment
What are the two things that ecosystem ecology address?
- flow of energy - complex networks of feeding relationships (food webs) among species
- production of biomass - total mass of living matter in a given area
What are trophic relationships?
- Levels of feeding (autotrophs (primary producers) food for heterotrophs (secondary consumers))
- Food chain (simple model): linear energy flow with species deeding on the proceeding organism
What is the food web (complex model)?
Interconnected food chains with multiple links among a community of organisms (full model of energy transfer)
What is energy flow via a trophic (energy) pyramid?
- Depicts how much biomass is present in groups of organisms
- Producers (autotrophs) at bottom and are eaten via food
- energy loos via consumption or heat
What are the tree components of biodiversity?
- species biodiversity
- genetic biodiversity
- ecological biodiversity
What is species biodiversity?
Species richness and abundance
-ex. richness of frog species (4,740 species)
What is genetic diversity?
Variation in genes within species
- ex. variation in size and color of a single frog species
What is ecological biodiversity?
Diversity in ecosystems, communities, and habitats
- ex. geographic variation in frog distributions and habitats
What are some top ecological problems we face?
- temperature
- overpopulation
- water resources
- pollution
- loss biodiversity
- bees
- over fishing
sea level rise
What is the importance of biodiversity?
- ecological services: allows for adjustments to changing environmental conditions and disturbances like fires and floods
- genetic diversity important for disease biology
- cleans eater, absorbs chemcials, provides oxygen, sequences carbon
What are ecosystem/ecological services and what are four example of them?
Any positive benefit that biodiversity provides to people
1. provisioning services
2. regulating servies
3. supporting service
4. cultural services
What are provisioning services?
Benefit extracted from biodiversity
-ex. drinking water, food, timber, medicinal uses
What are regulating services?
Benefit provided by ecological processes
-ex. pollination, decomposition, erosion/flood control, climate regulation
What are supporting services?
Benefits from having consistent ecological processes
- ex. photosynthesis, nutrient cycling, water cycle, creation of soils
What are cultural services?
Non-material benefit in the development of culture
- ex. knowledge building, recreation
What are eight examples of biodiversity loss?
- Exploitation of food webs and top predators
- exotic and invasive species
- changes in land use (forestry, agriculture, urbanization)
- Appropriation of freshwater supplies
- eutrophication of lakes and coastal oceans
- pollutants and contaminants
- stratospheric ozone (O3) depletion –> Montreal protocol (1987)
- Climate warming/change
What is the first example of biodiversity loss?
Decline of large ocean predators
- tuna, marlin, swordfish, sharks, cods, halibut, skates, and flounder have been fished down in the past 50 years
- serial depletion of top predators (fishing down the food web)
What is the second example of biodiversity loss?
- > 50,000 exotic species introduced to US alone
- scale is important (trans-continental, trans-oceanic, regional, local)
- 350 species of crayfish in US near 70% are imperiled by local exotic introduction fish and competitors
What is the importance of appropriation of freshwater supplies?
Humans currently use about 50% of global (available) freshwater, and were depleting deep water aquifers (much slower to recharge)
