Unit 3 Envi Sci

Equation for the growth rate of a country using CBR and CDR

(CBR +Immigration) - (CDR + Emigration)/ 10

K-selected species

K-selected species possess relatively stable populations fluctuating near the carrying capacity of the environment Traits - low development, low reproductive rate, late reproductive age, large body size, multiple reproductive cycles, long lifespan, strong competitive ability, and low offspring mortality. Examples - Elephants, horses, and humans

Why do r-selected species generally follow survivorship curve 3?

R selected species have a large amount of offspring per reproductive age. However they have a Type 3 survival curve which means that most of the offspring die off during their early ages and the few live to their old age.

Mortality

the frequency of death in a population.

Fecundity

the potential to for a female to become pregnant and carry that pregnancy to a live birth in demography,

Generalist Species

A generalist is a species that has a broad niche and is able to adapt to many environmental conditions. Traits - Broad Niche, not a picky eater, can live in multiple habitats Examples - Rats, Coyotes, Raccoons

Specialist Species

A specialist species, on the other hand, has a narrow niche and is not adaptable to change in their environment. Traits - Limited diet, specific habitats, highly sensitive to change, not adaptable to change in environment Examples - Panda, Hummingbird, Otter

Survivorship Curve

A survivorship curve is the graphic representation of the number of individuals in a population that can be expected to survive to any specific age.

Survivor Ship Curve 2

A type II survivorship curve shows a roughly constant mortality rate for the species through its entire life. This means that the individual's chance of dying is independent of their age. Type II survivorship curves are plotted as a diagonal line going downward on a graph.

What factors determine the carrying capacity for deer in a temperate forest ecosystem?

For deer to survive they need food, water, shelter/cover, and space to move about and find their daily requirements.

population momentum

Population momentum is a consequence of the demographic transition. Population momentum explains why a population will continue to grow even if the fertility rate declines. ... Population momentum is defined as the ratio of the size of the population at that new equilibrium level to the size of the initial population.

Replacement Level

Replacement level is the amount of fertility needed to keep the population the same from generation to generation.

theory of demographic transition

The demographic transition refers to the transition from high to lower birth a death rates in a country or region as development occurs and that country moves from a pre-industrial to an industrialized economic system.

Why do K-selected species generally follow survivorship curve 1?

They invest a lot of parental care to their offspring which is why their family sizes are smaller. Because time, energy and resources are invested into child rearing

How are K-selected species affected by invasive species?

They produce slowly so invasive species come into their environment and use lots of the resources that the K-selected species need.

List 3 factors that influence TFR

educational opportunities for females - Teaching them about contraceptives Religious/Cultural Beliefs - having big families as a normality government acts that affect childbearing - How many children a family is allowed to have

Describe how decreasing resources impact the carrying capacity for a given population

As resources are depleted, population growth rate slows and eventually stops: This is known as logistic growth. The population size at which growth stops is generally called the carrying capacity (K), which is the number of individuals of a particular population that the environment can support.

Biotic Potential

Biotic potential is defined as the maximum number of individuals a species can produce Whales - have low biotic potential b/c they reproduce at slow rates Salmon - have high biotic potential b/c they reproduce at very high rates

CBR

Crude birth rate (CBR) the number of births per 1,000 individuals per year.

density independent factor and density dependent factor

Density-dependent factors have varying impacts according to population size. Different species populations in the same ecosystem will be affected differently. Factors include: food availability, predator density and disease risk. Density-independent factors are not influenced by a species population size.

Describe the characteristics of a developed country

Developed economies have a stable government, good governance, and substantial capital investment. The people within such countries enjoy a high standard of living and economic stability. The social infrastructure is high, and the rate of inflation is favorable.

Describe the characteristics of a developing country

Developing countries have been suffering from common attributes like mass poverty, high population growth, lower living standards, illiteracy, unemployment and underemployment, underutilization of resources, socio-political variability, lack of good governance,

Dieback(die off)

Dieback refers to a rapid decrease in numbers experienced by a population of organisms that has temporarily exceeded

Overshoot

Ecological overshoot occurs when human demand exceeds the regenerative capacity of a natural ecosystem. Deer - are harvested at twice the rate they can regenerate

Describe the relationship between education for women and TFR

Educated women generally have fewer children than uneducated women. ... Thus, women with primary education tend to have 0-30% fewer children than uneducated women

demographic transition stage 3

In Stage 3 of the Demographic Transition Model (DTM), death rates are low and birth rates diminish, as a rule accordingly of enhanced economic conditions, an expansion in women's status and education, and access to contraception. ... Stage Three moves the population towards stability through a decline in the birth rate. Mexico

demographic transition stage 4

In Stage 4 of the Demographic Transition Model (DTM), birth rates and death rates are both low, stabilizing total population growth. ... As these factors play out the total fertility rate decreases until it reaches replacement level (2.1 births per woman), at which point the country enters Stage 5. U.S.

Survivor Ship Curve 3

In survivorship curve. The Type III curve, characteristic of small mammals, fishes, and invertebrates, is the opposite: it describes organisms with a high death rate (or low survivorship rate) immediately following birth.

IFR

Infant Mortality Rate. Definition. number of babies out of every 1,000 born who die before their first birthday Factors - Preterm birth and low birth weight. Injuries (e.g., suffocation). Sudden infant death syndrome. Maternal pregnancy complications.

Carrying Capacity

Largest number of individuals of a population that a environment can support

Thomas Multhus Theory

Malthus specifically stated that the human population increases geometrically, while food production increases arithmetically food production will not be able to keep up with growth in the human population, resulting in disease, famine, war, and calamity.

demographic transition stage 1

Stage 1 of the Demographic Transition Model (DTM) is characterized by a low population growth rate due to a high birth rate (number of annual births per one thousand people) and a high death rate (number of annual deaths per one thousand people). Brazil

demographic transition stage 2

Stage 2 of the Demographic Transition Model (DTM) is characterized by a rapid decrease in a country's death rate while the birth rate remains high. As such, the total population of a country in Stage 2 will rise because births outnumber deaths, not because the birth rate is rising. Guatemala

demographic transition stage 5

Stage 5: Total population is still high but starting to decline due to the birth rate falling (to 7 per 1,000) below the death rate (9 per 1,000). The population will start to fall as it is no longer replacing itself. The population is ageing and will gradually be dominated by older people. Japan

TFR

TFR stands for total fertility rate. When discussing human populations, this is the average number of children a woman has

The rule of 70

The rule of 70 is a way to estimate the time it takes to double a number based on its growth rate. The formula is as follows: Take the number 70 and divide it by the growth rate.

CDR

The total number of deaths in a year for every 1,000 people alive in the society.

Explain why replacement level fertility rate is higher in developing nations than in developed nations

This is because they have a higher mortality rate so more children are needed to keep it equal

Survivor Ship Curve 1

Type I or convex curves are characterized by high age-specific survival probability in early and middle life, followed by a rapid decline in survival in later life. They are typical of species that produce few offspring but care for them well, including humans and many other large mammals.

Limiting Resource

a particular natural resource that, when limited, determines the carrying capacity of an ecosystem for a particular species. Moose - Predation, habitat, hunting, and environmental conditions have all been implicated as regulatory mechanisms

Age Cohort

portion of individuals of each age in a population

Age Cohort

proportion of individuals of each age in a population.

r-selected species

r-selected species are those that emphasize high growth rates, typically exploit less-crowded ecological niches, and produce many offspring, each of which has a relatively low probability of surviving to adulthood Traits - Rapid development, High reproductive rate, Early reproductive age, Small body size, One reproductive cycle, Short lifespan. Examples - Mice, Rabbits, Weeds

Are invasive species K-selected or r-selected species? Why?

r-selected, because produce an abundance of offspring and grow/mature quickly