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Population Dynamics Terms.

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Presentation on theme: "Population Dynamics Terms."— Presentation transcript:

1 Population Dynamics Terms

2 Habitat- an ecological or environmental area that is inhabited by a particular species of animal, plant or other type of organism Species- taxonomic group whose members can interbreed

3 Population Size (#/area)- number of individual organisms in a population
Crude density- The number (or biomass) per unit total space Ecological density- the number (or biomass) per unit of habitat space (available area or volume that can actually be colonized by the population-where organisms exist)

4 Population Dispersion- the general pattern in which individuals are distributed through a specific area Clumped Random Uniform

5 Mark-Recapture Sampling
M/N=m/n Example: There is a fish population of unknown size in a lake. 26 fish are captured, marked, and released back into the lake. After 10 days 21 fish are captured of which 3 are marked...How do we use this information to figure out the population size?

6 Answer

7 Carrying Capacity- population size of the species that the environment can sustain indefinitely, given the food, habitat, water and other necessities available in the environment.

8 Factors that affect Population Growth
Population dynamics- changes in population characteristics determined by natality, mortality, immigration, and emigration Fecundity- the potential for a species to produce offspring in one life time

9 Factors that affect Population Growth
Natality- birthrate: the ratio of live births in an area to the population of that area; expressed per 1000 population per year Mortality- deathrate: the ratio of deaths in an area to the population of that area; expressed per 1000 per year Emigration- migration from a place (especially migration from your native country in order to settle in another) Immigration- migration into a place (especially migration to a country of which you are not a native in order to settle there)

10 x 100

11 Closed Population- A population that is closed to genetic material from the outside (zoo)
Open population- a population that is open to genetic material from the outside (forest)

12 Biotic Potential the maximum rate a population can increase under ideal conditions

13 Biotic Potential Birth potential- maximum reproductive capacity of a population if resources are unlimited. Full expression of the biotic potential of an organism is restricted by environmental resistance, any condition that inhibits the increase in number of the population. Capacity for survival Procreation- the sexual activity of conceiving and bearing offspring Length of reproductive cycle

14 Geometric Growth Formula
N(t+1)=N(t) λ

15 Exponential Growth: Formula
If a population has a constant birth rate through time and is never limited by food or disease, it has what is known as exponential growth. With exponential growth the birth rate alone controls how fast (or slow) the population grows. dN / dT = rN nt.html

16 Logistic Growth In most real populations both food and disease become important as conditions become crowded. There is an upper limit to the number of individuals the environment can support. Ecologists refer to this as the "carrying capacity" of the environment. Populations in this kind of environment show what is known as logistic growth. dN /dt = rmaxN[ (k-N) / k ] ogistic.html

17 Logistic Growth 1. Lag Phase 2. Log Phase 3. Stationary Phase 3 2 1

18 Environmental Resistance- All biotic and abiotic factors combining to limit explosion
Dynamic Equilibrium- lack of change in a system as inputs and outputs remain in balance. If changes do occur, then feedbacks will allow for correction

19 Density Dependent factor- factor that influences population regulation, having a greater impact of population density increases or decreases Density Independent factor- factors that influence population regulation regardless of population density

20 Competition Intraspecific Competition- when a species competes against other members of their own species. Competing for space, mates, food/water, and shelter. Interspecific Competion- interactions between individuals of different species for an essential common resource that is in limited supply. Competing for space, food/water, and shelter.

21 Interspecific Competition
Interference-interspecific competition that involves aggression between individuals of different species who fight over the same resource(s). Eg, birds of the same size over a bird house

22 Interspecific Competition
Exploitation-interspecific competition that involves consumption of shared resources by individuals of different species, where consumption by one species may limit resource availability to other species. Eg, zebra muscle

23 Interspecific Competition
Resource Partitioning-avoidance of, or reduction in, competition for similar resources by individuals of different species from reproducing successfully together; sharing of a resource, plant root depth

24 Predator Prey Cycle Predator Prey Relationship:
An interaction between two organisms of unlike species in which one of them acts as predator that captures and feeds on the other organism that serves as the prey. Echo effect Lynx-hare-hares increase, lynx increase

25 Predation predator (an organism that is hunting) feeds on its prey (the organism that is attacked); Capturing a prey as a means of maintaining life. Example: Lion and cub eating a Cape Buffalo

26 Predator: any animal that lives by preying on other animals
Prey: the animal being hunted Predator Prey

27 Co-evolution- When two species influence one another’s evolutionary history.
Bumblebees and the flowers they pollinate have coevolved so that both have become dependent on each other for survival.

28 Allee Effect- density dependent phenomenon that occurs when population cannot survive or fails to reproduce enough to offset mortality once the population density is too low; such populations usually do not survive Minimum viable population size Passenger pigeon

29 Ecological Niche an organism’s biological characteristics, including use of and interaction with abiotic and biotic resources and assimilate the wastes produced by a human population

30 Ecological Niche Fundamental Niche- the biological characteristics of the organism and the set of resources individuals in the population are theoretically capable of using under ideal conditions; hawks predator on mice.. But day/night... Realized Niche-more specific in that this sparrow might only eat mosquitoes, lives in top of the tree...more specific because of competition *TIE*

31 Camouflage A method organisms use to disguise and conceal themselves from the surrounding environment for protection as well as attack their prey. It is a form of mimicry

32 Camouflage Camouflage is a form of adaptation to the environment
Prevents animals from becoming another animal’s prey and makes it easier to find food Increases chances of survival therefore chances to reproduce Being able to camouflage is an advantage

33 Types of Camouflage Blending into surroundings.
Colour change. [Some animals developed a special adaptation that allows them to change their coloration when surrounding changes (changing of the seasons)] Disguising Animal’s Body Does not hide presence The animal’s appearance represents an object from its surroundings

34 Mimicry When a group of organisms have evolved to share common characteristics with another group or the environment.

35 Mimicry Batesian mimicry is when a harmless species imitates a dangerous species and therefore, this causes the potential predator to leave the species alone. Example: the viceroy butterfly (top) appears very similar to the noxious tasting monarch butterfly(bottom).

36 Mimicry Müllerian mimicry is when two harmful species mimic each other in their external appearance to scare away predators.

37 Defense Active: Passive Physical-porcupine Chemical-poison; tree frog
Hiding Camouflage visual warning Mimicry

38 Symbiosis Interactions in which two species live closely, often with a physical association.

39 Symbiosis: Parasitism
Beneficial to one species, but harmful to the other... Microparasites: Microscopic, rapid reproduction. Examples: Plasmodium a blood parasite causes malaria. Trypanosoma causes sleeping sickness.

40 Symbiosis: Parasitism
Endoparasites: Lives inside the body of their host. Example: Tapeworms.

41 Symbiosis: Parasitism
Ectoparasites: Live and feed on the outside surface of their host. Examples: Fleas, ticks, lice.

42 Symbiosis: Parasitism
Social Parasites: Manipulate the social behaviour of another species to complete their life cycle. Example: Brown headed cowbird

43 Symbiosis: Mutualism interaction is beneficial to both species.
Obligatory Mutualism Neither organism can grow or reproduce without the other. Examples: Beneficial bacteria in the large intestine of humans Examples: The Red-billed Oxpecker eats ticks on the impala's coat

44 Symbiosis: Commensalism
Interaction that is beneficial to one species, but the other species is unaffected. Rare in nature

45 ALL Formulas {[(B+I)-(D+E)] / N } X 100 Population Density:
D= N/S Average sample density [total number of individuals ] / [total sample area] Estimating population size using mark-recapture sampling N= Mn/ m Population Change {[(B+I)-(D+E)] / N } X 100 Geometric Growth: N(t+1)=N(t) λ Exponential growth dN / dT = rN Logistics Growth dN /dt = rmaxN[ (k-N) / k ]

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