Name:_________________________________________________ Ecology Unit, Chapter 14 Notes
14.1: Habitat and Niche
Key Concept: Every organism has a habitat and a niche
What’s the difference between a habitat and a niche?
¡ ______________________: All of the biotic & abiotic factors in the area where an organism lives (i.e. grass, trees, watering hole)
¡ ______________________: Includes the same as the habitat. (All of the physical, chemical, and biological factors that a species needs to survive, stay healthy, and reproduce), ______________________________________________________________ (i.e. type of food species eats, temperature it can tolerate, time of day it is active, how it interacts with others)
¡ Habitat is where a species ___________________ (“address”), niche is _______________ it lives there (“job”)
14.2: Community Interactions
Key concept: Organisms interact as individuals and as populations.
Competition & predation are two important ways in which species interact.
1. Competition: Two organisms fight for the same limited resources.
¡ Intraspecific: members of the __________________ species
¡ Interspecific: ____________________________ species
2. Predation: One organism captures and feeds upon another organism.
Symbiosis is a close ecological relationship between two or more organisms of different species that live in direct contact with one another.
Three types of symbiosis:
¡ _____________________________: Both species benefit from one another. Example: bat & cactus
¡ Commensalism: One species benefits from the other, the other is neither ___________________________.
Example: Humans & demodicids
¡ _____________________________: One organism benefits while the other is harmed. Ex.: Tapeworms
¡ _______________________________: Live in the tissues and organs of the host
¡ Ectoparasite: Lives on the _________________________ of the host
14.4: Population Growth Patterns
Key concept: Populations grow in predictable patterns
Population size changes. Why?
¡ Increased Population
1. __________________________: Movement of individuals into a population from another population
Ex: fruit flies and banana
2._____________________: increases the number of individuals in a population. Ex; additional flies born
¡ Decreased Population
3. _______________________________: Movement of individuals out of a population and into another population
Ex: some flies get out.
4. ___________________: the size of the population decreases when individuals die. Ex; fruit flies get squashed.
¡ The rate of growth for a population is directly determined by _________________________________________.
Types of Population Growth
¡ Exponential Growth – occurs when individuals reproduce at a __________________________________________________________________; population size increases dramatically over a period of time.
*J-curve, human population
¡ Logistic Growth – population rises exponentially and then growth slows when it reaches its ______________________________________________.
*Carrying capacity: The maximum number of individuals of a particular species that the environment can _______________________________________________________________.
*S-shaped Curve
What affects the carrying capacity of a population?
¡ Factors that have the greatest effect at keeping down the size of a population are called ___________________________________________________.
¡ They can be ________________________________________or ____________________________________________________.
Density-dependent limiting factors:
*Affected by the number of _____________________________ in a given area.
*Examples: Competition, __________________________, parasitism, ______________________
Density-independent limiting factors:
*Aspects of the environment that limit population growth _____________________________________. *Examples: Unusual weather, natural disasters, __________________________________.
14.5 Ecological Succession
Key concept: Ecological succession is a process of change in the species that make up a community.
Succession occurs following a disturbance in an ecosystem.
¡ Succession: the sequence of biotic changes that regenerate a _______________________ community or create a community in a previously ___________________________ area.
*Primary succession:
¡ The establishment and development of an ecosystem in an area that was previously __________________.
¡ Can begin due to melting glaciers, ______________________________, or landslides.
¡ First organisms to live in a previously uninhabited area are called pioneer species.
¡ Examples: lichens and mosses that can break rock down into smaller pieces.
*Secondary Succession:
¡ The reestablishment of a ____________________ ecosystem in an area where the soil was left intact.
¡ Plants and other organisms that remain start the process of regrowth.
¡ Small disturbances start the process ______________________________. Example: forest fire, tree falling