Ch. 52 & 54 Flashcards
How many levels of ecological study are there?
6
What questions might ecologists ask when they discover a new species?
- What environmental factors limit where it is found?
- How do variations in an organism’s food supply or interactions with other species affect the size of their population?
Name the ecological studies in order?
Organismal, population, community, ecosystem, landscape, global.
What is a population?
A group individuals of the same species living in the same area.
Organismal Ecology:
Concerned with an organism’s structure, physiology, and behavior.
Population Ecology:
Analyzes factors that affect population size and how and why it changes over time.
Community Ecology:
Examines how interactions between species such as predation and competition affect community studcture and organization.
Ecosystem Ecology:
Emphasizes energy flow and chemical cycling between organisms and the environment.
Landscape Ecology:
Focuses on factors controlling exchanges of energy and materials/ organisms across multiple ecosystems.
Global Ecology:
Examines hoe the regional exchange of energy and materials influences the functioning and distribution of organisms across the biosphere.
What 2 types of ecology are we studying?
Community and Ecosystem
What is a community and what aspects are important to ecologists?
A group of populations of different species in an area.
How do interactions between species affect the community organization and structure?
What is climate?
the long-term prevailing weather conditions in a given area.
4 major physical components of a climate?
Temperature
Precipitation
Sunlight
Wind
What are global patterns determined by?
Solar energy and the Earth’s movement in space
The warming effect of the sun impacts?
- Temperature variations
- Circulation (air and water0
- Evaporation
- Causes latitudinal variations in climate.
What to factors can modify regional and local climate?
- Large bodies of water
- Mountain ranges
Seasonal variations are greater ______ ______, and include differences in ___________, __________ , and __________.
- Towards poles
- Day length, solar radiation, and temperature.
What is microclimate?
Fine localized pattern: casts shade, alters evaporation from the sun.
Ex: forest trees, a log can shelter from the extremes, tree holes.
What is an ecological niche?
How organisms use resources (abiotic/biotic)
Ecologically similar species may coexist but differ and specialize.
Competitive Exclusion principle
Two species competing for the same limited resources (local elimination)
Fundamental vs Realized niche
Fundamental: Theoretical, physiology
Realized: Actual, competition
Community structure
Number of species found in a community, particular species present and relative abundance of these species.
Interspecific Interactions
includes competition, predation, herbivory, parasitism, commensalism.
Competition
(-/-) interaction that occurs when both species use resources that limit survival and reproduction.
Resource Partitioning
Differentiation of niches that enables similar species to coexist in a community.
Competition Exclusive
One slight reproductive advantage will eventually lead to local elimination of inferior competitor.
Populations allopatric
geographically separate
Populations sympatric
geologically overlapping
Character Displacement
Tendency for characteristics to diverge more in sympatric or allopatric of 2 species
Exploitation
any (+/-) interaction.
-predation, herbivory, parasitism
Predation
(+/-) interaction which an individual of one species, predator, kills and eats, prey.
Prey
Also has adaptations or behavioral defenses like hiding, fleeing, herds.
Typically, don’t use self-defense
Predators
Have adaptations to find/identify prey.
Nocturnal, fangs, poison, fast and agile
Aposematic coloration
Animals with effective chemical defenses exhibit a warning coloration. Predators avoid these colors.
Cryptic coloration
“camo” makes prey hard to see
Batesian Mimicry
palatable/harmless species mimics a harmful species not closely related. Can even involve behavior.
Mullerian Mimicry
2+ more unpalatable prey resembles each other. More unpalatable prey, the more predators learn to avoid them.
Herbivory
(+/-) interaction. Organism/herbivore eats parts of plant/alga harming it but not killing it.
Has adaptations, heightened sense of smell to examine plants and their value.
-Plants can use toxins or chemicals since they can’t run.
Parasitism
(+/-) interaction. When parasites get nourishment from host, which is harmed in the process.
Endoparasite
Parasite lives in host
Ectoparasite
Parasite lives on host
Positive interactions
(+/+) or (+/0)
3 types of exploitive interactions (+/-)
Predation
Herbivory
Parasitism
2 types of positive interactions
Mutualism
Commensalism
Mutualism
(+/+) benefits both species; common in nature. Some mutualism interacting individuals depend on the other for survival/reproduction. Both partners incur costs/benefits
Commensalism
(+/0) benefits 1 individual but doesn’t harm/ benefit the other.
Ex: wildflowers grow in trees shade
Species Diversity
Variety of different kinds of organisms that make up the community
Species Richness
number of different species in a community
Tropic Structure
Feeding relationships between organisms. Transfer of chemicals energy from plants —> autotrophs —> herbivores —> carnivores —> decomposers.
Relative Abundance
proportion of each species represents of all individuals in community.
Higher diversity communities are…
generally, more productive and better able/ withstand from environment stresses.
Food Webs
group of food chains linked together. Each position of an organism has trophic level.
Energetic Hypothesis
Suggests length of food chain is limited by inefficiency of energy transfer. 10 percent of energy stored in organic matter is converted to next trophic level
Foundation species
Have strong effects on their communities as a result of their high abundance.
Keystone species
Not the most abundant in a community but exert strong control.
Ecosystem Engineers
Species that create/dramatically alter their environment
Bottom-Up control
Abundance of organisms at each trophic level is limited by nutrient supply/ availability of food at lower trophic levels.
Top-Down control
Abundance of organisms at each trophic level controlled by abundance of consumers at higher trophic levels. Predators limit herbivores, herbivores limit plants.
Disturbances
keep many communities from reaching a state of equilibrium in species diversity/ composition.
Ex: storm, flood, drought, human activity, fire
Nonequilibrium model
describes most communities as constantly changing after disturbance.
Intermediate Disturbance Hypothesis
states moderate levels of disturbance foster greater species diversity than high/low levels of disturbance.
Ecological Succession
Disturbed area may be colonized by a variety of species which are gradually replaced by other species, which are in turn replaced by other species.
Primary Succession
When colonization of species replaced by other and replaced again occurs on a virtually lifeless area.
3 processes of primary succession arriving species
- early arrivals facilitate for later arrivals by making environment suitable
- early arrivals inhibit establishment so later arriving organisms occur in spite of not because of
- Early arrivals may be completely independent /tolerate conditions neither hurt/help.
Secondary succession
Recolonization of an area after a major disturbance has removed most/not all organisms in a community. After disturbance area returns to og state.
2 large scale factors contributing to community diversity
- Latitudinal Gradients
- Area Effects
Latitudinal Gradients
More species inhibit the tropics: plants and animals bc of evolutionary history and climate. Species diversity highest in tropics bc of sunlight & precipitation
Area Effects
Diversity increases with increasing area
Island Equilibrium Model
-Method for predicting species diversity; number of species at equilibrium relative to island size and distance
-Immigration rate decreases as number of species on island gets larger while extinction rate increases. Island size and distance from mainland are important too.
-Small islands have less immigration and higher extinction
-Island close to mainland has higher immigration and lower extinction
Pathogens alter community structure locally and globally
- Marine/ocean: coral reefs–> white band disease
- Terrestrial: oak trees (SOD)
3/4 human diseases come from ______ pathogens through vectors
Zoonic
2 types of mutualism
Obligate: both species are completely dependent on each other
Facultative: Partners may coexist without being entirely dependent on each other.
2 components of community structure
- How diverse they are
- The feeding relationships of their species/feeding relationships
Shannon Diversity Index
A tool (equation) to calculate indexes of diversity based on species richness and relative abundance.
