Midterm Flashcards
What can ecology teach us about public health?
Natural Services: Marshes are the best filtration for toxins in water. Leaving them intact can reduce the burden of water treatment systems.
Biomedical: scientists will try to harness the chemicals of certain organisms and synthesis them for the treatment of human diseases.
What can ecology teach us about Agriculture and fishing?
- Part of knowing the ecology of pests can help us introduce other factors to maintain our crops rather than using pesticides.
- Ecological research has notified the harm of dams on fish and it has helped us create structures that will work along side wildlife
What is the difference between enzootic and epzootic cycles?
Enzootic cycle: does not involve humans (mice transmit diseases amongst themselves.)
Epzootic cycle: involves humans
What is the study of demography?
study of populations
How do you calculate density of an area?
Density = size / range
size is number of individuals
range is how wide the population is spread
What are the three types of population distributions?
Random distribution: no organism has an affect on where the other one will go.
Clumped distribution: happens when resources are distributed patchy. Likleyness of young surviving is low
Uniform: All organisms feed on the same resources (sparse), or due to predators
What is the mark recapture method?
Method of finding a population.
C/R*M= N
C= all caught second day
R= Recaptures
M= All caught first day
How to calculate intrinsic growth rate / per capita growth rate
r = (change in pop*change in time) / original pop)
What is Exponential vs Logistic growth and what are leading causes for each?
Exponential growth: Doesn’t slow down even when a population gets really large
- is caused by unlimmited resources and no predators
Logistic growth:
Reaches a plateau with maximum population an environment can hold (carrying capacity)
- Density indipendent regulation includes storm, cold, drought
- Density dependent ragulation include predators, competition, space, food, disease
What do type 1, type 2, and type 3 survival curves mean?
Type 1) Survive early years then show steep decline near last part of lifespan (humans and other large animals)
Type 2) Lose steady numbers throughout lifespan(Small mammals and birds)
Type 3) Many die in early years and those that do survive show slow declines overtime (fish, frogs, insects, herbaceous trees)
What is the difference between r and k strategists
K strategists (predictable environments): larger but fewer offspring
- Few offspring
* Delayed reproduction
* Infrequent reproduction
* Long lifespan
R- strategies (unpredictable environment/ patchy resources):
- Many offspring
* Early reproduction
* Frequent reproduction
* Short life span
What is a metapopulation
A metapopulation is a population of populations which gives organisms the opportunity to move from place to place.
highly isolated populations are more at risk of extinction because they are less diverse.
What are source sink dynamics?
Sources are areas of land that have high intrinsic growth rate and creates immigration to other sources or sinks.
Sinks have low intrinsic growth rate and would go extinct if it wasn’t for sources.
What are demographic and environmental factors that contribute to extinction.
Demographic factors occur more in small populations (e.g. small
isolated patches)
* Only older, non-reproductive individuals remain
* Sex ratio altered by chance so too few on one sex
Environmental factors
* Hurricanes
* Drought
* Fire
* Floods
What is a niche? and what are the specific types of niches?
A niche is specific set of environmental conditions required by an organism or functions it preforms in nature (indicator species of healthy environmental conditions)
Fundamental niche includes all habitat that is potentially available to the species
Realized niche is the subset of features that are actually occupied (constrained by predators/ competitors)
What is resource partitioning?
Though there are limited resources, species are able to divide them amongst each other. (ex/ different birds eating from different parts of the tree)
What do the terms interference competition, exploitative competition and competetive exclusion mean?
Interference comptition is a direct physical competition for resources
Exploitative competition is indirect as one species reduces resources for another
Competitive exclusion states that are competing for the same resources can not coexist in a community.
Describe these four defense mechanisms:
Cryptic colouration
Aposematic colouration
Batesian Mimicry
Mullerian mimicry
List anything else you know about defense mechanisms.
Cryptic colouration = camoflauge
Aposematic colouration: bright colours that signal toxicity
Batesian mimicry: harmless species evolved to imitate warning signal of harmful species
Mullerian mimicry: Both have very strong defences but they look the same
anti herbivore Adaptations example
Different types of herbivores have adaptations such as their beak, teeth, etc.
- plants also adapt so that when they are damaged or to warn other trees they can change their chemical balence to make themselves taste bad
different types of symbiotic relationships
+/+ mutualism
+/0 commercialism
+/- parasitism
Ways to control species sampling
- Repeated samples
- different types of traps
What is formula for species diversity index?
H = -(pln pA)+(pBln pB) + (pCln pC…)
High H values mean habitats with MORE SPECIES and MORE EVEN
DISTRIBUTION of species
What is island Biogeography, and what are some reasons for why it works the way it does?
There is the relationship between the area of an island and the number of species present (larger islands have more species)
- maybe larger areas are less prone to extinction (more species creates a buffer)
- maybe larger islands have larger shoreline which might promote more immigration
What is Allopatric speciation?
When a species separates into two isolated groups (blocked by a mountain range, water way, etc.), each species will develop differently based on their unique habitat
Why is there no trophic level for parasites?
Parasites are found all throughout the trophic system.
What is succession?
Primary succession and secondary succession/
Natural communities replace or succeed over one another over time.
Primary succession- starts with bare rock (maybe a volcanic eruption)
Secondary succession- soil is already present (maybe a forest fire)
What is an ecological trap?
When an organism is attracted to poor quality habitats where their fitness i compromised.
What is the difference between interspective and intraspective interactions
intraspecfic competition is same species interactions
interspecific competition is two different species
