Ecological Concepts: Species, Population, and Environment

Generalist species

Species that tend to be advantaged in habitats that are changing.

Specialist species

Species that tend to be advantaged in habitats that remain constant.

K-selected species

Species that tend to be large, have few offspring per reproduction event, live in stable environments, expend significant energy for each offspring, mature after many years of extended youth and parental care, have long life spans/life expectancy, and reproduce more than once in their lifetime.

r-selected species

Species that tend to be small, have many offspring, expend or invest minimal energy for each offspring, mature early, have short life spans, and may reproduce only once in their lifetime.

Biotic potential

The maximum reproductive rate of a population in ideal conditions.

Survivorship curve

A line that displays the relative survival rates of a cohort—a group of individuals of the same age—in a population, from birth to the maximum age reached by any one cohort member.

Type I survivorship curve

A curve typically followed by K-selected species.

Type II survivorship curve

A curve that can be followed by K-selected species.

Type III survivorship curve

A curve typically followed by r-selected species.

Carrying capacity

The maximum population size that an environment can sustain indefinitely.

Overshoot

when a population exceeds its carrying capacity.

Dieback

A major ecological effect of population overshoot, often severe to catastrophic due to lack of available resources leading to famine, disease, and/or conflict.

Resource availability

The extent to which resources are available to support population growth.

Population growth

The increase in the number of individuals in a population, which is limited by environmental factors, especially by the available resources and space.

Density-independent factors

Factors that affect population growth regardless of population size, such as major storms, fires, heat waves, or droughts.

Density-dependent factors

Factors that affect population growth based on population size, such as access to clean water and air, food availability, disease transmission, or territory size.

Rule of 70

A formula that states dividing the number 70 by the percentage population growth rate approximates the population's doubling time.

Malthusian theory

A theory that outlines basic factors that limit human population growth.

Global wind patterns

Primarily result from the equator, resulting in density differences and the Coriolis effect.

Incoming solar radiation (insolation)

The Earth's main source of energy and is dependent on season and latitude.

Angle of the sun's rays

Determines the intensity of the solar radiation.

Highest solar radiation

Received at the equator and decreases toward the poles.

Solar radiation variation

Varies seasonally, with the most radiation received during the location's longest summer day and the least on the shortest winter day.

Tilt of Earth's axis

Causes the Earth's seasons and the number of hours of daylight in a particular location.

Weather and climate

Affected not only by the sun's energy but by geologic and geographic factors, such as mountains and ocean temperature.

Rain shadow

A region of land that has become drier because a higher elevation area blocks precipitation from reaching the land.

Clearcutting

Can be economically advantageous but leads to soil erosion, increased soil and stream temperatures, and flooding.

Forests

Contain trees that absorb pollutants and store carbon dioxide.

Urbanization

Can lead to depletion of resources and saltwater intrusion in the hydrologic cycle.

Impervious surfaces

Human-made structures that do not allow water to reach the soil, leading to flooding.

Urban sprawl

The change in population distribution from high population density areas to low density suburbs that spread into rural lands.

Sustainability

Refers to humans living on Earth and their use of resources without depletion of the resources for future generations.

Environmental indicators

Can guide humans to sustainability and include biological diversity, food production, average global surface temperatures and CO2 concentrations, human population, and resource depletion.

Sustainable yield

The amount of a renewable resource that can be taken without reducing the available supply.

Urban runoff mitigation methods

Include replacing traditional pavement with permeable pavement, planting trees, increased use of public transportation, and building up, not out.

Deforestation mitigation methods

Include reforestation, using and buying wood harvested by ecologically sustainable forestry techniques, and reusing wood.

Integrated pest management (IPM)

A method to protect forests from pathogens and insects.

Prescribed burn

A method by which forests are set on fire under controlled conditions in order to reduce the occurrence of natural fires.

Noise pollution

Sound at levels high enough to cause physiological stress and hearing loss.

Sources of noise pollution

Include transportation, construction, and domestic and industrial activity.

Noise Pollution Effects on Animals

Effects of noise pollution on animals include stress, masking of sounds used to communicate or hunt, damaged hearing, and changes to migratory routes.

Invasive Species

Invasive species are species that can live, and sometimes thrive, outside of their normal habitat and threaten native species.

Generalist, r-selected Species

Invasive species are often generalist, r-selected species that may outcompete native species for resources.

Control of Invasive Species

Invasive species can be controlled through a variety of human interventions.

Endangered Species Factors

Factors that can lead to a species becoming threatened with extinction include extensive hunting, limited diet, competition from invasive species, and specific habitat requirements.

Species Adaptation to Changes

Species that can adapt to changes in their environment or move to a new environment are less likely to face extinction.

Selective Pressures

Selective pressures are factors that change the behaviors and fitness of organisms within an environment.

Resource Competition

Species in a given ecosystem compete for resources like territory, food, mates, and habitat, which may lead to endangerment or extinction.

Strategies to Protect Animal Populations

Strategies to protect animal populations include criminalizing poaching, protecting habitats, and legislation.

HIPPCO

HIPPCO describes the main factors leading to a decrease in biodiversity: habitat destruction, invasive species, population growth, pollution, climate change, and over-exploitation.

Habitat Fragmentation

Habitat fragmentation occurs when large habitats are broken into smaller, isolated areas due to construction, agriculture, or logging.

Effects of Habitat Fragmentation

The scale of habitat fragmentation that adversely affects inhabitants varies from species to species within an ecosystem.

Global Climate Change Effects

Global climate change can cause habitat loss via changes in temperature, precipitation, and sea level rise.

Domestication of Organisms

Some organisms, such as honeybee colonies and domestic livestock, have been domesticated for economic returns, which can negatively impact biodiversity.

ESA

ESA stands for the Endangered Species Act, a legislation aimed at protecting endangered species.

C.I.T.I.E.S

C.I.T.I.E.S stands for the Convention on International Trade in Endangered Species of Wild Fauna and Flora.

Clean Water Act

The Clean Water Act is legislation aimed at regulating water pollution.

Safe Water Drinking Act

The Safe Water Drinking Act is legislation aimed at ensuring safe drinking water.

Primary Productivity Equation

The equation for primary productivity is GPP = NPP + R, where GPP is Gross Primary Productivity, NPP is Net Primary Productivity, and R is Respiration.

Natural Energy Resources Distribution

The global distribution of natural energy resources, such as ores, coal, crude oil, and gas, is not uniform and depends on the region's geologic history.

Fossil Fuels Combustion

Combustion of fossil fuels is a chemical reaction between the fuel and oxygen that yields carbon dioxide, water, and released energy.

Fossil Fuels Energy Generation

Energy from fossil fuels is produced by burning those fuels to generate heat, which turns water into steam that drives a turbine connected to a generator.

Methods of Extracting Fossil Fuels

Humans use methods like oil drilling (land and offshore) and fracking to extract fossil fuels for energy generation.

Fracking Consequences

Fracking can cause groundwater contamination and the release of VOCs (volatile organic compounds).

Energy conservation methods at home

Adjusting the thermostat to reduce the use of heat/AC, conserving water, use of energy-efficient appliances, and conservation landscaping.

Energy conservation methods on a large scale

Improving fuel economy for vehicles, using BEF's (battery electric vehicles) and hybrid vehicles, using public transportation, and implementing green building design features.

Air pollutants from coal combustion

Releases air pollutants including CO2, SO2, toxic metals and particulates.

Fossil fuels and nitrogen oxides

The combustion of fossil fuels releases nitrogen oxides (NOx) into the atmosphere, leading to the production of ozone, formation of photochemical smog, and conversion to nitric acid, causing acid rain.

Other pollutants from fossil fuel combustion

Includes CO, hydrocarbon, and particulate matter.

Impact of SO2 on air quality

Air quality can be affected through the release of SO2 during the burning of fossil fuels, mainly diesel fuels.

Clean Air Act and lead regulation

The Environmental Protection Agency (EPA) regulated the use of lead, particularly in fuels, which dramatically decreased the amount of lead in the atmosphere.

Primary and secondary pollutants

Air pollutants can be primary or secondary pollutants.

Formation of photochemical smog

Photochemical smog is formed when NOx and VOC's react with heat and sunlight to produce a variety of pollutants.

Environmental factors affecting photochemical smog

Many environmental factors affect the formation of photochemical smog.

NOx production and ozone concentration

NOx is produced early in the day, while ozone concentrations peak in the afternoon and are higher in the summer.

Volatile Organic Compounds (VOCs)

VOCs such as formaldehyde and gasoline evaporate or sublimate at room temperature; trees are a natural source of VOCs.

Urban areas and photochemical smog

Photochemical smog often forms in urban areas because of the large number of motor vehicles.

Reducing photochemical smog

Photochemical smog can be reduced through the reduction of NOx and VOCs.

Health effects of photochemical smog

Photochemical smog can harm human health, causing respiratory problems and eye irritation.

Thermal inversion

During a thermal inversion, the normal temperature gradient in the atmosphere is altered, trapping pollution close to the ground.

Natural sources of CO2

CO2 appears naturally in the atmosphere from sources such as respiration, decomposition, and volcanic eruptions.

Methods to reduce air pollutants

Include regulatory practices, conservation practices, and alternative fuels.

Vapor recovery nozzle

An air pollution control device on a gasoline pump that prevents fumes from escaping into the atmosphere when fueling a vehicle.

Catalytic converter

An air pollution control device for internal combustion engines that converts pollutants (CO, NOx, hydrocarbons) in exhaust into less harmful molecules (CO2, N2, O2, and H2O).

Wet and dry scrubbers

Air pollution control devices that remove particulates and/or gases from industrial exhaust streams.

Pollution reduction methods for coal-burning power plants

Include scrubbers and electrostatic precipitators.

Acid deposition

Due to NOx and SOx from anthropogenic and natural sources in the atmosphere.

Sources of NOx causing acid deposition

Come from vehicles and coal-burning power plants.

Sources of SO2 causing acid deposition

Come from coal-burning power plants.

Impact of acid deposition

Mainly affects communities that are downwind from coal-burning power plants.

Acid rain

Precipitation that has been made acidic by atmospheric pollution, leading to environmental harm.

Acidification

The process by which soils and bodies of water become more acidic, often due to acid rain.

Limestone bedrock

A type of bedrock that can neutralize the effects of acid rain on lakes and ponds.

Heavy metals

Toxic metals that can contaminate groundwater and impact drinking water supply, often from industrial activities.

Litter

Discarded materials that can create hazards for wildlife and introduce toxins into the food chain.

Sediment

Particles that settle in waterways, which can reduce light infiltration and disrupt habitats.

Methylmercury

A highly toxic form of mercury produced when elemental mercury is converted by bacteria in aquatic environments.

Solid waste

Any discarded material that is not a liquid or gas, generated in various sectors.

Landfills

Sites where solid waste is disposed of, which can contaminate groundwater and release harmful gases.

E-waste

Discarded electronic devices such as televisions, cell phones, and computers.