Unit 5:Lesson 4 Flashcards
dispersal
-movement of individuals (or gametes) away from their area of origin or from centers of high population density
species transplants
ecologists may observe the results of transplants to determine if dispersal is a key factor limiting species distribution
- sucess=some organisms reproduce sustainably
- means that species potential range> than actual range
Habitat Selection
some individuals tend to avoid certain habitats, even when they are suitable and accessible
Limiting Biotic Factors
- negative interactions with predators or herbivores restrict potential to survive and reproduce
- polinators, food resources, parasites, pathogens, and competing organisms may also be limiting factors
Limiting factors: Temperature
-temps outside a certain range may damage or stress an organism
Limiting Factors: Water and Oxygen
- some organisms may dry up if not enough water
- low oxygen levels in deep water or water with much organic matter limits organism processes
Limiting Factors: Salinity
- affects water balance of organisms through osmosis
- some do have osmoregulating adaptations
Limiting Factors: Sunlight
- too little can limit distribution of photosynthetic species
- high light levels can increase temp stress
- UV radiation can inhibit trees at high level elevations
Limiting Factor: Rock and Soil
-ph, mineral composition, and physical structures
interspecific interactions
includes competititon, predation, herbivory, symbiosis, and facilitation
interspecific competition
-/- interaction, species compete for a resource that limits their growth and survival
Competitive Exclusion
When two species, who have identical niches compete for the same resource, in the absence of disturbance, one species will use resources more effectively and grow while the other will be eliminated
ecological niche
the sum of a species use of resources in an environment
- fundamental: potential
- realized: actual
resource partitioning
the difference between niches that enable similar species to coexist in a community
-time can also differentiate niches
Character Displacement
tendency for characteristics to diverge more in sympatric (competitive) than allopatric populations of two species
Predation
+/- interaction
Predator adaptations
- have acute sense to detect prey
- adaptations to help them detect and subdue prey
- may use mimicry to lure prey
prey adaptations
- behavioral defenses;hiding, fleeing, forming groups, alarm calls, some vigorously protect young, some have mechanical/chemical defenses
- mimicry and coloration
cryptic coloration
camouflage that makes prey difficult to see
aposematic coloration
warning coloration
Batesian mimicry
a palatable (harmless) species mimics an unpalatable (harmful one)
Mullerian mimicry
2 or more unpalatable species resemble each other
- predators learn to avoid these prey quicker