What are limiting factors? Give examples of physical and biological limiting factors.
Any factor that makes it difficult for an organism to live, grow and reproduce
Physical: temperature, wetness, light
Biological: competition, predation, mutualism
Define Eurytopic and Stenotypic Species.
Eurytopic: ecologically tolerant
Stenotypic: ecologically intolerant
Name the 5 tolerance zones, as well as the species richness found in those zones.
Upper/Lower Zone of intolerance - Species absent
Upper/Lower Zone of physiological stress - Low population
Range of optimum - Area of greatest of abundance
What is Bergman's Rule?
For closely related mammals and birds, the larger form occur at higher latitudes
What is Bergman's Fine-Tuned Rule? Give an example of this.
Body size often strongly correlated with climate due to larger organisms having less surface area per volume and, thus, are better able to conserve energy.
What is Allen's Rule?
Species in cold environments have shorter extremities relative to body mass
What is Gloger's Rule?
Coloration of related forms is correlated with humidity.
Describe the differences between heliophytes and sciophytes.
Heliophytes: small thick leaves, high number of stomata
Sciophytes: large, soft leaves, with a high level of chlorophyll
What is Liebig's Law of the Minimum?
It states that growth is controlled not by the total amount of resources available, but by the scarcest resource (limiting factor).
If a species requires say 3 things to live, air, moisture, and sun, then we can expect the range at which this species thrives is different for all these dimensions. By singling out the dimension in which it is most sensitive, you can determine its range. However, we now know it is not just one dimension, but the multiple interplay that determines this.
What is a niche?
The area defined by all the physical and biological conditions the species requires to survive
Name and describe the two types of interspecific competition.
Exploitative: use up resources
Interference: aggressive dominance (black walnut tree with toxins in soil)
What is competitive exclusion?
When a species becomes so adept at getting their food source that they bully other species out of getting that resource.
Define and give examples of temporal and spatial separation.
Temporal separation is when different species which hunt for the same things hunt for them at different times. For example, sparrows and owls, who hunt for mice during the day and during the night respectively. Or flowers which blossom at different times throughout the year so there will always be enough pollinators for everyone.
Spatial separation is when species specialize in exploiting different parts of a resource (land, tree, etc...). Example is the different types of beetles in a tree. Some are found near the base, while others are found in the middle or top and each eat different parts of it.
Define euryphagous and stenophagous species.
Euryphagous: non-selective predators
Stenophagous: Selective predators, limited by food distribution
Describe a case of Mutualism between organisms.
Bats and certain flowers depend on each other. The flower has an intense sulphuric scent, inconspicuous colours, and sounds differently to a bat if it's ready to release pollen.