LEC 17: Population Dynamics

These flashcards cover key concepts, definitions, and formulas related to population dynamics, focusing on the common mud turtle's reproductive rates, generation time, and different population growth models.

What is the net reproductive rate denoted as?

R0 or R naught.

What is the geometric rate of increase represented by?

λ (Lambda).

What does 'r' represent in population dynamics?

The per capita rate of increase.

What turtle species was closely examined in this lecture?

Common mud turtle (Kinosternon subrubrum).

How is R0 calculated from lx and mx?

R0 = Σ lxmx.

If R0 is less than 1, what does this indicate about the population?

The population is declining.

What is the generation time (T) formula?

T = Σ x lx mx / R0.

What does lx represent in the context of population dynamics?

The proportion of individuals surviving at age x.

What does mx represent in population dynamics?

Fecundity, or the average number of daughters per mother at age x.

How do you determine the average generation time given by T?

The average age at which a female gives birth to her offspring.

What is the per capita rate of increase (r) equation?

r = b - d (where b is per capita birth rate and d is per capita death rate).

What does a negative value for r indicate about the population?

The population is declining.

What type of population growth is characterized by pulsed reproduction?

Geometric population growth.

What does a J-shaped curve represent in population studies?

Exponential growth of a population.

What is the relationship between R0 and λ for species with discrete generations?

R0 = λ.

What is the intrinsic rate of increase denoted as?

rmax.

What is 'K' in the context of logistic growth?

Carrying capacity - the maximum population size that an environment can sustain.

When does population growth reach its maximum?

When resources are ideal, under exponential growth conditions.

What term describes populations that experience limited resources?

Logistic growth.

What is the formula for exponential growth?

Nt = N0 e^(rt).

What is the equation for calculating population size in geometric growth?

Nt = N0 λ^t.

What contributes to a population stabilizing at carrying capacity K?

When birth + immigration = death + emigration.

What behavior is observed in populations before reaching K?

Initial exponential growth followed by a slowdown.

How does logistic growth change as N approaches K?

Growth slows and stops as N approaches K.

What indicates a stable population during growth?

r = 0 (births equal deaths).

In logistic growth, what happens when N is small?

Growth is characterized mainly by the rmax term.

How does a population's size change in logistic growth as N increases?

The growth rate approaches 0 as N approaches K.

What is the calculation for dN/dt in logistic growth?

dN/dt = rmax N (1 - N/K).

What does logistic growth take into account compared to exponential growth?

Limitations on resources that slow growth.

What does environmental carrying capacity mean?

The maximum number of individuals that can be supported by the environment.

How is per capita growth rate expressed in logistic models?

Using the equation dN/dT = rmaxN(1 - N/K).

What are the implications of a positive r value in population growth?

The population is increasing.

When is R0 considered stable?

When R0 = 1.

In which population model does each generation's size change based on a constant ratio multiplied by current population size?

Exponential growth.

What is the formula to predict future population size in logistic models?

Nt = K / (1 + (K/N0 - 1)e^(-rmax t)).

What influences the shapes observed in demographic curves?

Conditions of resources and reproductive strategies.

What is the behavior of populations that exhibit exponential growth under ideal conditions?

They grow rapidly and continuously.

What happens to populations experiencing resource limitation over time?

Population growth declines and stabilizes at K.

What are common examples of organisms that exhibit geometric growth?

Species with pulsed reproduction and non-overlapping generations.

What is the significance of studying population growth in ecology?

To understand and predict ecological dynamics and biodiversity.

How do ecological models adjust for real-world limitations?

By incorporating resource limitations into growth equations.

What factors lead to unstable population growth in biological systems?

Competing for limited resources as population density increases.