Presentation on theme: "Chapter 3 Communities, Biomes, and Ecosystems 3.1 Community Ecology A biological community is a group of interacting populations that occupy the same."— Presentation transcript:
Chapter 3 Communities, Biomes, and Ecosystems
3.1 Community Ecology A biological community is a group of interacting populations that occupy the same area at the same time
Communities Organisms rely on one another to survive Abiotic factors affect communities and the organisms in them Organisms adapt to the conditions they live in Cactus retaining water in the harsh climate of a desert Depending on which factors are present, organisms can survive in one ecosystem, but not others
Limiting Factors Any abiotic or biotic factor that limits the numbers, reproduction, or distribution of organisms Includes sunlight, temperature, climate, water, nutrients, fire, soil chemistry, space, and other living things How would temperature be a limiting factor for polar bears?
Range of Tolerance The upper and lower limits that define the conditions in which an organism can survive Ideal water temp for steelhead trout is between 9°C and 25°C The ability of an organism to survive in certain abiotic or biotic factors is called tolerance
Ecological Succession The living and nonliving parts of an ecosystem change over a period of time Forest fire The changes that take place in a community as it gets older is called SUCCESSION
Succession Succession happens SLOWLY! So it can be hard to see happening.
Primary Succession occurs at an area of NEWLY EXPOSED rock (no soil) that has never been occupied by any living things (biotic factors)
Pioneer Species Lichens – a combination of fungus and algae Lichens begin to grow on the bare rock Since they are the first organisms to appear, they are called pioneer species Pioneer species help to create soil by secreting acids that break down the rock
Climax Communities A mature community eventually develops from bare rock Climax Community – the stable, mature community that results when there is little change in the composition of species It is the final stage of succession in a community, however, because of ecological disturbances, climax communities are unlikely to occur
Secondary Succession Occurs when a community has been removed due to fire, flood, windstorm, etc. New species may begin to occupy the habitat Over time, the species belonging to the mature community may return
Secondary Succession The orderly and predictable change that takes place after a community of organisms has been removed, but the soil has remained intact.
Chapter 4 Population Ecology
4.1 Population Dynamics Populations of species are described by density, spatial distribution, and growth rate Population Density – the number of organisms per unit area
Spatial Distribution Dispersion – the pattern of spacing of a population within an area Uniform, clumped groups, or random One primary factor in the pattern is availability of resources
Population Range No population, not even humans, occupies all habitats in the biosphere A species may not be able to expand it population range because it cannot survive the abiotic or biotic conditions found in the expanded range Abiotic conditions – temperature, rainfall, sunlight, humidity level Biotic conditions – predators, competitors, parasites
Population Limiting Factors Factors that keep a population from continuing to increase Density-independent Density-dependent
Population Limiting Factors Density-Independent any factor that does not depend on the number of members in the population Usually abiotic natural events like the weather (drought, flooding, etc.) human interference Density-Dependent any factor that depends on the number of members in a population Usually biotic Competition – density is high, resources are low Disease – density is high Parasites – density is high
Population Growth Rate Explains how fast a given population grows Emigration – number of individuals moving away from a population Immigration – number of individuals moving into a population Most populations remain the same size from year to year
Population Growth Rate A population stops increasing when the number of births is less than the number of deaths, or when emigration (moving out) exceeds immigration (moving in)
Carrying Capacity Maximum number of species an environment can support for the long term Limited by energy, water, oxygen,
Reproductive Patterns Species of organisms vary in the number of births per reproduction cycle, the age that reproduction begins, and in the life span of the organisms Plants and animals are placed into groups based on their reproductive factors R-strategists K-strategists
Reproductive Patterns R-Strategists Rate strategy Live in an environment that fluctuate Usually small organisms (mice, fruit fly) Short life spans, produce many offspring Usually controlled by density-independent factors STRATEGY: produce as many offspring as possible in a short period of time K-Strategists Carrying-capacity Live in environments that are predictable Larger organisms (elephant) Long life span, produce few offspring Controlled by density- dependent factors STRATEGY: produce fewer offspring that have a better chance of living
4.2 Human Population Demography: the study of human population size, density, distribution, movement, and birth and death rates
Advances For years, environmental conditions kept the human population size below carrying capacity Humans have altered the environment to change the carrying capacity
Advances Agricultural advances Domestication of animals Technology Medicine Improvements in shelter
Human Population Growth Rate Although the population is still growing, the growth rate has slowed
Trends in Human Population Growth Can be altered by war and disease Demographic Transition – change in population from high birth/death rates to low birth/death rates
Zero Population Growth (ZPG) when births plus immigration = deaths plus emigration The population has stopped growing because births and deaths occur at the same rate
Human Carrying Capacity Scientists are concerned about the population reaching or exceeding the carrying capacity Resources from the biosphere used by each person must also be limited
1. A 2. B 3. C 4. D CDQ 1 A. emigration B. imitation C. immigration D. migration Population Ecology Chapter 4 Chapter Diagnostic Questions What term is used to describe the number of individuals moving into a population?
1. A 2. B 3. C 4. D CDQ 2 Population Ecology Chapter 4 Chapter Diagnostic Questions B. number of organisms in an area C. characteristics of a population D. manner in which a population grows A. pattern of spacing of a population in anarea What is population density?
1. A 2. B 3. C 4. D CDQ 3 Population Ecology Chapter 4 Chapter Diagnostic Questions A. when birth rate equals death rate B. when death rate exceeds birth rate C. when birth rate exceeds death rate D. when there are zero births When does zero population growth occur?
1. A 2. B 3. C 4. D FQ 1 Population Ecology Chapter 4 A. disease B. fire C. flooding D. weather 4.1 Formative Questions Which is a density-dependent factor?
1. A 2. B 3. C 4. D FQ 2 Population Ecology Chapter 4 A. competition B. extreme cold C. parasites D. predation 4.1 Formative Questions Which is a density-independent factor?
1. A 2. B 3. C 4. D FQ 3 Population Ecology Chapter 4 A. emigration B. predation C. available nutrients D. extreme temperatures 4.1 Formative Questions Which factor can limit the carrying capacity of a population?
1. A 2. B 3. C 4. D FQ 4 Population Ecology Chapter Formative Questions A. bioinformatics B. demography C. ecology D. ethnography The study of the size, density, distribution, and movement of the human population is _______.
1. A 2. B 3. C 4. D FQ 5 Population Ecology Chapter Formative Questions A. decreased agriculture B. famine and wars C. setbacks in medicine D. voluntary population control Which is a primary reason for the decline in the percent growth of the human population after 1962?
1. A 2. B 3. C 4. D FQ 6 Population Ecology Chapter Formative Questions A. CDC B. HPG C. PGR D. ZPG What will happen to the human population when the birthrate equals the death rate?
1. A 2. B 3. C 4. D CAQ 1 Population Ecology Chapter 4 A. exponential B. spatial C. genetic D. logistic Chapter Assessment Questions Which type of population growth model does this graph represent?
1. A 2. B 3. C 4. D CAQ 2 Population Ecology Chapter 4 A. India has very little land for farming. B. Germany is smaller per acre than the United States. C. More land is used to support an individual in the United States. D. A person in Indonesia requires more land than a person in Brazil. Chapter Assessment Questions Based on the information in the graph, infer which statement accurately represents the information provided.
Use the graph to explain the growth of the mice population. Population Ecology Chapter 4 Chapter Assessment Questions CAQ 3
Answer: If two adult mice breed and produce a litter and their offspring survive to breed, then the population grows slowly at first. This slow growth is defined as the lag phase. The rate of population growth begins to increase rapidly because the total number of organisms that are able to reproduce has increased. Exponential growth occurs when the growth rate is proportional to the size of the population. All populations grow exponentially until some limiting factor slows the population’s growth. Population Ecology Chapter 4 Chapter Assessment Questions CAQ 4
1. A 2. B 3. C 4. D STP 1 Population Ecology Chapter 4 A B. 23 C. 230 D Standardized Test Practice An ecologist estimates a population density of 2.3 lemmings per square meter of tundra. What would be the approximate number of lemmings over 1000 square meters of tundra?
1. A 2. B 3. C 4. D STP 2 Population Ecology Chapter 4 Standardized Test Practice A. density B. dispersion C. logistic spacing D. spatial distribution The ecologist finds that over a 1000m 2 plot of tundra, lemmings tend to concentrate in clumps in drier areas. What is the term for this pattern of spacing?
1. A 2. B 3. C 4. D STP 3 Population Ecology Chapter 4 Standardized Test Practice A. It is density-dependent. B. It is limited by biotic factors. C. It has a limited spatial distribution. D. It is randomly dispersed in the environment. Brine shrimp are able to survive only in certain lakes that have a very high salt concentration. Which is the correct population characteristic of brine shrimp?
1. A 2. B 3. C 4. D STP 4 Population Ecology Chapter 4 Standardized Test Practice Why does the population growth level off at 10,000? A. Biotic factors have made survival difficult. B. The population has reached its carrying capacity. C. Density-independent factors have slowed the growth of the population. D. Immigration into the population has reached the maximum limit.
1. A 2. B 3. C 4. D STP 5 Population Ecology Chapter 4 Standardized Test Practice Which organism is the best example of a k-strategist? A. wolf B. grasshopper C. rabbit D. whale
Population Ecology Glencoe Biology Transparencies Chapter 4
Population Ecology Image Bank Chapter 4
population density dispersion density-independent factor density-dependent factor population growth rate emigration immigration carrying capacity Population Ecology Vocabulary Section 1 Chapter 4
demography demographic transition zero population growth (ZPG) age structure Population Ecology Vocabulary Section 2 Chapter 4
Population Ecology Chapter 4 Visualizing Population Characteristics Visualizing Population Characteristics Characteristics of Population Growth Characteristics of Population Growth Animation