a group of individuals of the same species inhabiting the same area
The number of individuals added to a population through reproduction over a particular time period
Humans born per 1,000 individuals per year.
shows the proportion of individuals likely to survive to each age
Three types of survivorship curves
species with high mortality only in old age-species with mortality equal between classes-species with high mortality in young
Population growth rate
the birthrate minus the death rate over a given period of time usually 1 year
is the number of individuals of each age in the population
is the number of individuals per unit area
Movement of individuals from densely populated locations to new areas
the inherent reproductive capacity of a species (biological ability to produce offspring)
This is the first portion of the curve; slow population growth
Exponential Growth Phase (Log Phase)
More organisms are reproducing, causing accelerated growth; this continues as long as birth rate exceeds death rate
The population growth rate slows as the death rate and birthrate come to equal one another.
Stable Equilibrium Phase
The death rate and birth rate become equal and the population stops growing
Factors that prevent unlimited population growth
All of the different limiting factors that act on a population
Extrinsic limiting factors
come from outside the population
Intrinsic limiting factors
originate within the population and exercise control over it.
Density-dependent limiting factors
become more effective as the density of the population increases.
Density-independent limiting factors
population- controlling influences that are not related to the density of the population.
Categories of Limiting Factors
Raw material availability, Energy availability, Accumulation of waste products, Interactions among organisms
the maximum sustainable population for an area.
carrying capacity can be influenced by environmental differences such as
successional changes, climate variations, disease epidemics, forest fires floods natural disasters, nutrient levels in aquatic ecosystems
Two reproductive strategies
K and R
Organisms that typically reach a stable population as the population reaches the carrying capacity.
Typically, these are small organisms that have a short life, produce many offspring, exploit unstable environments, and do not reach a carrying capacity.
Characteristics of K-strategists
usually occupy relatively stable environments, large organisms, long-lived, produce few offspring, provide parental care, controlled by density dependent limiting factors.
per capita income exceeding $10,000, europe canada US japan australia new zealand, combined population of 1.2 billion, stable populations
per capita income less than $5,000, all remaining countries of the world, nearly 3 billion live on less than $2 a day, high population growth rates
relates the size of the population to available resources.
is a measure of the land area required to provide the resources and absorb the wastes of a population
is the study of populations and their characteristics, how those characteristics affect growth, and the consequences of that growth.
total fertility rate of a population
is the number of children a woman has during her lifetime.
Zero population growth
is when the birth rate equals death rate.
Gross national income (GNI)
is an index of purchasing power measuring total goods and services generated by citizens of a country
a model of population growth based on historical, social, and economic development of Europe and N. America.
Examples of countries who are reducing automobile use in cities
london=$20 to drive in city, Hong Long= monthly bill from sensors,Rome and florence= cars banned from 7:30am-7:30pm
Cars altered people's lifestyles
Vacationers could travel greater distance, Vacationers could travel greater distance, In the suburbs, labor-saving, energy-consuming devices became essential in the home,
Industrial nations use energy roughly for
residential/commercial uses, industrial uses, transportation. %16 of energy is used for residential and commercial purposes in US. %68 used for air conditioning and heating
Most electrical energy is produced as a result of
burning fossil fuel
Price of gas is determined by
purchasing and processing crude oil, taxes, politics, natural disasters
the organization of Petroleum Exporting Countries. Consists of 13 members. These nations control over %75 of the world estimated oil reserves. agree to regulate production to maintain a price greater that $22 a barrel
Nonrenewable energy sources
are those whose resources are being used faster than can be replenished. Coal, oil, and natural gas
Renewable energy sources
replenish themselves or are continuously present as a feature of the environment.Solar, geothermal, tidal, etc. Some forms are referred to as perpetual energy.
is a naturally occurring substance of use to humans that can potentially be extracted using current technology.
is a known deposit that can be economically extracted using current technology, under certain economic conditions.
Reserves are _______ than resources
most abundant fossil fuel
three categories of coal
1. Lignite----Is least desirable because of its high moisture content. 2. Bituminous----Most widely used because it is most abundant and easiest to mine. 3.Anthracite----Has the highest energy content and is cleanest burning, but is hard to obtain.
two extraction methods
Surface mining (strip mining), which is the process of removing material on top of a vein, is efficient but destructive. Underground mining minimizes surface disturbance, but is costly and dangerous. Underground mining minimizes surface disturbance, but is costly and dangerous.
Many miners suffer from black lung disease, a respiratory condition that results from the accumulation of fine coal-dust particles in the miners' lungs.
Issues with coal
bulkey and causes transport problems, mining creates dust pollution, burning coal releases pollutants (carbon and sulfer)
Reservoir construction causes significant environmental and social damage
Loss of farmland or forest land due to flooding. Community relocation. Prevention of fish migrations. Trapping of silt fills in reservoir and stops flow of nutrients downstream. Mercury accumulation.
is created when flowing water is captured and turned into electricity.
the sun's energy is converted directly to heat and used at collection site.
active heating system
the sun's energy is converted into heat, but transported elsewhere to be used
passive solar system
light energy is transformed to heat energy when it is absorbed by a surface.
active solar system
requires a solar collector, a pump, and a system of pipes to transfer the heat from the site of production to the area to be heated.
A photovoltaic cell (PV)
is a solid-state semiconductor that converts sunlight directly into electricity.
All biomass is produced by green plants that convert sunlight into plant material through photosynthesis.
4 sources of biomass energy
1. fuelwood 2. municipal and industrial wastes 3. Agricultural crop residues ad animal wastes 4. energy plantations
Crops suitable for energy use must
Good energy crops have a very high yield of dry material per unit of land. The amount of energy that can be produced from a biomass crop must be more than the amount of energy required to grow a crop.
Technologies capable of converting biomass into energy
direct combustion and cogeneration, ethanol production, anaerobic digestion, pyrolysis