Population Biology and Environmental Impact

A collection of flashcards based on lecture notes covering concepts in population biology and the environmental impact of human activities.

What is population biology?

The study of populations of organisms, including their size, structure, growth, and interactions with the environment.

What are density-dependent factors that affect population growth?

Factors that influence population size based on density, including disease, food availability, space, and predation.

How do density-dependent factors impact population size?

They reduce population size by increasing mortality, such as through predator-prey oscillations.

What are density-independent factors affecting population growth?

Factors that affect populations regardless of their density, such as drought, fire, or habitat destruction.

What are the two different reproductive strategies?

K-selection (fewer offspring, higher parental care) and r-selection (many offspring, little parental care).

What is the maximum life span, and how does it vary by species?

The longest period an organism can live, varying greatly among species.

What are some factors that increase population size?

Births and immigration are key factors that increase population size.

What are some factors that decrease population size?

Deaths and emigration are key factors that decrease population size.

What are the three types of survivorship curves?

Type I: Low mortality early in life (e.g., elephants); Type II: Constant mortality rate (e.g., birds); Type III: High mortality early in life (e.g., sea turtles).

What is conservation biology?

The management of biodiversity to protect and preserve species, habitats, and ecosystems.

What is a key question in conservation biology?

Determining the minimum population size needed for a species' long-term survival.

What is Population Viability Analysis (PVA)?

A method to determine the minimum viable population size for species survival.

What are key aspects of human population studies?

Human Population Growth, Factors Determining Population Growth, and Demographics of Populations.

What is the net gain of people per second in the world?

About 2.5 people per second.

What are two views on human population growth?

Ecologists are concerned about overpopulation and environmental degradation; Economists believe technology will solve related problems.

When did human population growth begin increasing rapidly?

Around 1600, due to advancements in agriculture, healthcare, and hygiene.

How did early societies regulate population size?

Through cultural taboos, abstinence, and infanticide.

What is carrying capacity?

The maximum population size an environment can sustain based on available resources.

What is a community?

A community consists of multiple populations in an area that may interact.

What is interspecific competition?

Competition between members of different species for limited resources.

What is intraspecific competition?

Competition among members of the same species.

What does population biology study?

It examines population size, structure, dynamics, and interactions with the environment.

What factors influence human population dynamics?

Birth rates, death rates, immigration, and emigration.

How do populations grow through time?

Populations may grow exponentially under ideal conditions but eventually face limiting factors.

What is exponential growth?

A population increases rapidly without limiting factors.

Why does exponential growth always have limits?

Resources such as food, water, and space eventually run out.

What is carrying capacity (K)?

The maximum population size an environment can support without depleting resources.

What is logistic growth?

Population growth slows as resources become scarce, forming an S-shaped curve.

Why do population sizes fluctuate?

Environmental conditions, such as seasonal changes or disasters, cause variation in population sizes.

What is overshoot?

When a population exceeds the environment’s carrying capacity, leading to resource depletion.

What is a population crash?

A sudden decline in population size after exceeding carrying capacity.

What is the boom-and-bust cycle?

Repeated cycles of population growth (boom) followed by crashes (bust).

What are density-dependent factors affecting population growth?

Factors that intensify as population size increases, such as disease, food scarcity, and predation.

What are density-independent factors affecting population growth?

Factors that affect populations regardless of their density, like natural disasters.

What are the two reproductive strategies?

r-selection (many offspring, little care) & K-selection (few offspring, more care).

What are r-selected species?

Species that reproduce quickly with high offspring mortality and little parental care.

What are K-selected species?

Species that reproduce slowly, invest in offspring, and approach carrying capacity.

What factors increase population size?

Births and immigration.

What factors decrease population size?

Deaths and emigration.

What is human population growth?

The increase in the number of individuals in the human species over time.

How fast is the human population growing?

Every second, 4-5 children are born while only 2 people die.

What are the two views on population growth?

Ecologists worry overpopulation causes environmental degradation; Economists believe in technology's ability to solve issues.

Why did human population growth accelerate after 1600?

Advancements in agriculture, power sources, healthcare, and hygiene.

What is carrying capacity in human populations?

The maximum number of people Earth can support sustainably.

How does technology affect carrying capacity?

It increases carrying capacity through advancements in agriculture, engineering, and medicine.

What is the environmental impact formula?

Environmental Impact = P × A × T (Population size × Affluence × Technology).

What is demography?

The study of human populations, including births, deaths, distribution, and size.

What are the two demographic worlds?

Wealthy, aging, and shrinking vs. Poor, young, and rapidly growing.

Why are some populations declining?

Low birth rates in wealthier nations or diseases like AIDS in affected regions.

What factors influence total population growth?

Births, deaths, immigration, and emigration.

What is zero population growth (ZPG)?

When births plus immigration equals deaths plus emigration.

What has happened to fertility rates worldwide?

They have declined everywhere except in Africa.

What is life expectancy?

The average age a newborn can expect to reach in a given society.

What factors have increased life expectancy?

Improved nutrition, sanitation, and education.

What is the dependency ratio?

The ratio of non-working individuals (young and elderly) to working individuals.

What is age structure?

The distribution of people among different age groups in a population.

What is the ethical debate on human population growth?

Should we focus on max population or the optimal number ensuring quality of life and reducing environmental impact?

What are some common waste disposal methods?

Open dumps, sanitary landfills, and waste exportation.

What is an open dump?

A method of waste disposal that releases hazardous materials.

What is a sanitary landfill?

A waste disposal site where refuse is compacted and covered to reduce environmental impact.

How is e-waste managed?

About 80% of electronic waste is exported to other countries for processing.

What are the three main waste disposal methods?

Open Dumps, Sanitary Landfills, and Waste Exportation.

Why is waste disposal becoming more expensive?

Rising land prices and shipping fees increase costs.

What are incineration and energy recovery?

Methods of burning waste to generate heat for buildings or electricity.

What are the two types of incinerators?

Refuse-Derived Fuel (sorted waste) and Mass Burn (all waste).

How does recycling help reduce waste?

Recycling reprocesses materials into new products, saving money and reducing landfill pressure.

What are the benefits of recycling?

Saves money, raw materials, and landfill space.

Why is reuse often more efficient than recycling?

Reuse prevents waste altogether, reducing processing costs and energy use.

What is hazardous waste?

Any discarded material that is toxic, carcinogenic, mutagenic, corrosive, or explosive.

What federal law regulates hazardous waste?

The Resource Conservation and Recovery Act (RCRA).

What is the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA)?

Also known as the Superfund Act; aims to clean up toxic waste sites.

What are Superfund sites?

Heavily contaminated locations requiring federal cleanup efforts.

How much does hazardous waste cleanup cost in the U.S.?

Estimates range from $370 billion to $1.7 trillion.

What are the three main hazardous waste management strategies?

Produce less waste, convert waste to less hazardous forms, store waste permanently.

What is bioremediation?

The use of microorganisms to detoxify hazardous waste.

What are the risks of hazardous waste storage?

Transport accidents, financial responsibility, and long-term site maintenance.

Difference between exponential and logistic growth?

Exponential growth increases rapidly without resource limitation; logistic growth slows as it reaches carrying capacity.

What is predator-prey oscillation?

Cyclic changes in predator and prey populations, where predator numbers increase following a rise in prey, then decline as prey populations drop.

What is the minimum viable population?

The smallest population needed to avoid extinction.