Chapter 14 - Interactions in Ecosystems Flashcards
What is a habitat? 14.1
Where an organism lives
Include abiotic and biotic factors
What is an ecological niche? 14.1
It is composed of all of the physical, chemical, and biological factors that a species needs to survive, stay healthy, and reproduce; its role.
Includes:
Food: what kind, how it is obtained, etc…
Abiotic conditions: temperature, amount of water needed, etc…
Behavior: when it is active during the day, where and when it reproduces, etc…
What is the difference between a habitat and a niche? 14.1
A habitat is where a species lives and a niche is how it lives within its habitat.
What happens in mutualism? 14.2
Both species benefit (+/+)
What happens in commensalism? 14.2
One member benefits, the other is not helped nor harmed (+/0)
What happens in parasitism? 14.2
One organism lives off the other organism while harming it (+/-)
What is ectoparasite vs. endoparasite? 14.2
Ectoparasite—lives outside the host
Endoparasite—lives inside the host
What is symbiosis and what are the three types? 14.2
Close ecological relationship between two or more organisms of different species that live in direct contact with one another
Mutualism
Commensalism
Parasitism
What is competition? 14.2
When 2 organisms fight for the same limited resources
What are the two types of competition? 14.2
Interspecific competition—between two different species
Intraspecific competition—between members of the same species
What is predation? 14.2
Process in which one organism captures and feeds upon another organism
What are the 3 important features of population? 14.3
- Population size—the number of individuals in a population
- Population density—the number of individuals that live in a given area
- Dispersion—the way individuals of a population are arranged in an area
How do you calculate population density? 14.3
# of individuals/ = population density Area (units2)
What are the 3 patterns of dispersion? 14.3
Random—ex. Solitary animals such as sloths
Even or Uniform—occur at regular intervals—ex. Nesting sites of gannet on page 437
Clumped—individuals are bunched together in clusters—ex. Schools of fish
What is a survivorship curve?
How many are there? 14.3
Diagram that shows the number of surviving members over time from a measured set of births
3
What happens in type 1 survivorship curve? 14.3
Type I—low level of infant mortality and a population that will mostly survive to old age
common in large mammals (and humans); characterized by infant care to ensure infant survival
What happens in type 2 survivorship curve? 14.3
Type II—survivorship rate is roughly equal at all ages of an organism’s life
common in birds, small mammals, and some reptiles; susceptible to predation and disease
What happens in type 3 survivorship curve? 14.3
Type III—very high birth rate but very high infant mortality rate, few move on to adulthood
invertebrates, fish, amphibians, and plants; many offspring die from predation
What are 4 factors that affect population size? 14.4
Immigration—movement of individuals into a population from another population
Births—increase the number of individuals in a population
Emigration—movement of individuals out of a population and into another population
Deaths—decrease the number of individuals in a population
What is an exponential growth and what happens in it? 14.4
Exponential Growth Curve (J-shaped curve)—a curve in which the rate of population growth stays the same, as a result the population size increases steadily
Resources (food and space) are abundant
J-curve is a population that will grow if all individuals survive and reproduce at maximum capacity with no limiting factors
What are the 2 phases of exponential growth? 14.4
Two phases:
Lag – little or no increase
Exponential – very rapid increase - # of individuals doubles in time intervals
What is a logistic growth and what happens in it? 14.4
Logistic Model (S curve) –a population model where exponential growth is limited by depleting resources causing a population to reach carrying capacity; relative stability that occurs after Lag and Exponential Phase
What is the carrying capacity? 14.4
Carrying capacity—the maximum number of individuals an environment can support; where birth rate equals the death rate
In nature, carrying capacity can change when the environment changes
What are the two types of limiting factors? 14.4
Density-independent
Density-dependent
What is density-dependent limiting factor? 14.4
Density-dependent limiting factor—limited resources whose rates of depletion depend on the density of the population using them
Ex. Competition, predation, parasitism and disease
What is density-independent limiting factor? 14.4
Density-independent factor—environmental conditions that limit population growth regardless of population size
Ex. Weather, natural disasters, human activity
What is a population crash? 14.4
A dramatic decline in the size of a population over a short period of time
What are R-Strategists?
R-strategists
Ex: Bacteria, Cockroaches, mosquitoes, most insects, some plants
Grow exponentially when environmental conditions allow them to reproduce
Temporarily large populations
Short life span
Reproduce early in life
Produce many offspring during each time of reproduction
Small offspring with little or no parental care
When environmental conditions worsen, population size drops drastically
-TYPE 3
What are K-Strategists?
Ex. Gorillas, whales, humans, elephants, Redwood trees, tigers
Populations grow slowly and population density is usually near the carrying capacity of the environment
Long life span
Few young with a slow maturing process
Reproduction late in life
Parents often provide extensive care for their young
Many endangered species are these
-TYPE 1
What is ecological succession? 14.5
Sequence of biotic changes that regenerate a damaged community or create a community in a previously uninhabited area
What are the two types of ecological succession? 14.5
Primary
Secondary
What is primary succession and what are some examples? 14.5
Primary succession (Figure 14.16)—succession that occurs in an uninhabited area
Examples
new lava or rock from a volcano, makes a new island or a new landscape
sand bar that arises from shifting sands in the ocean
exposure of rock surfaces by a land slide or glacial retreat
meteor makes a depression that fills with rainwater or fresh water from underground streams
sand dunes can be great for observing primary succession
Rock surface Lichens Decomposers Mosses Ferns, shrubs Pines Hardwoods
Ex. Lichen on rock starts to die and make a foundation of soil for things like moss, then grass and ferns, bushes, trees, forest
What is secondary succession and what are some examples? 14.5
Secondary succession (Figure 14.17)—the sequence of community changes that takes place after a community is disrupted by natural disasters or human actions
Ex. Fire, natural disasters, human activity, etc…
Secondary succession is continually happening after small disturbances which kick start succession.
What are pioneer species? 14.5
First species in an area; usually lichen or moss which breakdown rock
Which succession occurs more often presently? 14.5
Secondary
Which type of succession takes a longer time to complete? 14.5
Primary
What’s the difference between emigration and immigration? 14.4
Immigration is the movement of individuals into a population from another while emigration is the movement of individuals out of a population into another
