The number of _____________ per unit area Chapter 4 Population Ecology 4.1 Population Dynamics Population Density The number of _____________ per unit area # of Organisms Square miles Spatial Distribution _______________ is the pattern of spacing of a population.

Chapter 4 Population Ecology 4.1 Population Dynamics Population Ranges The area a species lives in that is limited by the _____________________ in the surrounding area. Common dolphin Pupfish

Density-Independent Factors Chapter 4 Population Ecology 4.1 Population Dynamics – Reducing Factors Density-Independent Factors ___________depend on the number of members in a population per unit area Weather events Fire Human alterations of the landscape Air, land, and water pollution

Density-Dependent Factors Chapter 4 Population Ecology 4.1 Population Dynamics – Reducing Factors Density-Dependent Factors _____________on the number of members in a population per unit Biotic factors We will do this in class Disease Population Biology Competition Parasites

Population Growth Rate Chapter 4 Population Ecology 4.1 Population Dynamics Population Growth Rate The population growth rate (PGR) explains how ________ a given population grows. The natality of a population is the ________ in a given time period.

Exponential Growth Model Chapter 4 Population Ecology 4.1 Population Dynamics Exponential Growth Model Exponential growth occurs and produces a growth rate chart that looks like a ____. All populations grow exponentially until some ____________ slows the population’s growth.

Chapter 4 Population Ecology 4.1 Population Dynamics Logistic Growth Model The population’s growth slows or stops following ___________growth, at the population’s carrying capacity. Exponential Growth

Chapter 4 Population Ecology 4.1 Population Dynamics A population stops increasing when the number of births is less than the number of deaths or when _____________ (moving away) exceeds _____________ (moving in).

Chapter 4 Population Ecology 4.1 Population Dynamics Carrying Capacity The maximum number of individuals of a species an environment can support for the long term is the ____________________. Carrying capacity is limited by the energy, water, oxygen, and nutrients available.

Reproductive Patterns Chapter 4 Population Ecology 4.1 Population Dynamics Reproductive Patterns Species of organisms vary in: 1. the number of births per reproduction cycle 2. the age that reproduction begins 3. the life span of the organism

4.2 Human Population Human Population Growth Chapter 4 Population Ecology 4.2 Human Population Human Population Growth The study of human population size, density, distribution, movement, and birth and death rates is demography.

Technological Advances Chapter 4 Population Ecology 4.2 Human Population Technological Advances For thousands of years, the size of the human population remained at a relatively constant number below the environment’s carrying capacity. Humans are now able to alter the environment in ways that have changed its carrying capacity.

Human Population Growth Rate Chapter 4 Population Ecology 4.2 Human Population Human Population Growth Rate Although still growing, the rate has slowed.

Trends in Human Population Growth Chapter 4 Population Ecology 4.2 Human Population Trends in Human Population Growth Human population growth is not the same in all countries.

Zero Population Growth Chapter 4 Population Ecology 4.2 Human Population Zero Population Growth Zero population growth (ZPG) occurs when the birthrate equals the death rate. Eventually pre-reproductive, reproductive, and post-reproductive ages should be approximately equal.

pre-reproductive stage, reproductive stage, and post- Chapter 4 Population Ecology 4.2 Human Population Age Structure A population’s ______________________ is the number of males and females in each of three age groups: pre-reproductive stage, reproductive stage, and post- reproductive stage.

Human Carrying Capacity Chapter 4 Population Ecology 4.2 Human Population Human Carrying Capacity Scientists are concerned about the human population ___________________the carrying capacity. An important factor is the amount of __________ from the biosphere that are used by each person.