Ecology Unit Population Ecology Ecology study of the
- Slides: 38
Ecology Unit: Population Ecology • Ecology: study of the interactions between organisms and the living and nonliving components of their environment. Vocabulary • Ecosystem Components: • Abiotic Factors: nonliving. The physical and chemical components of the environment. • Biotic Factors: living, these include all of the living things that affect the organism. © 2011 Pearson Education, Inc.
Review Levels of Organization • Biosphere: most inclusive level of organization. This is the thin volume of earth and its atmosphere that supports live. • Ecosystem: All organisms and the non-living environment. • Community: All the interacting organisms living in an area. • Population: All the members of a species that live in one place at one time. © 2011 Pearson Education, Inc.
Ecology Unit Energy Flow Review • Energy flow through a system involves, producers, consumers and decomposers • Ecologist use ecological pyramids to represent relationships among trophic levels (ex. Pyramids of Energy, Biomass and Numbers) © 2011 Pearson Education, Inc.
An Energy Pyramid for a Prairie Ecosystem: The 10% Law © 2011 Pearson Education, Inc.
Energy Transfer and Loss Heat Secondary Consumer Producer Primary Consumer Heat Chemicals Heat Detritus Feeders © 2011 Pearson Education, Inc.
Ecology Unit • Cycles of matter • Biogeochemical Cycles: nutrients move through the biosphere in a series of physical and biological processes (unlike energy, nutrients can be used over and over) • Examples: • Water Cycle: alternation of evaporation and transporation, condensation and precipitation • Nitrogen Cycle: decomposers put nitrogen back into soil • Carbon and Oxygen Cycle: involves photosynthesis and respiration. © 2011 Pearson Education, Inc.
Water vapor in atmosphere Evaporation from land & Evaporation transpiration from ocean from plants Precipitation over land Precipitation over ocean The Hydrologic Cycle Reservoirs Processes/ Locations Water in ocean Surface (reservoir) runoff Groundwater seepage © 2011 Pearson Education, Inc.
The Nitrogen Cycle Nitrogen in in Atmosphere Reservoir Producers Uptake Dentitrifying bacteria by plants Electrical storms produce nitrate Reservoirs Processes/ Locations Trophic Levels/ Organisms Consumers Wastes, Dead bodies Soil bacteria and detritus feeders Ammonia & nitrate Nitrogen-fixing bacteria in legume roots and soil © 2011 Pearson Education, Inc.
The Carbon Cycle CO 22 in atmosphere (reservoir) Reservoirs Burning of CO 2 dissolved fossil fuels Fire in ocean Respitation (reservoir) Consumers Processes/ Locations Trophic Levels/ Organisms Producers Wastes, Dead bodies Soil bacteria & detritus feeders © 2011 Pearson Education, Inc.
Population Growth • Populations grow with births and immigration • They decline with deaths and emigration Population Growth: = Change in population number (Births + Immigration) – (Deaths + Emigration) Species do not occupy all parts of their habitat at once. • Niche: the specific role or way of life of a species within it’s environment. • Niche includes the range of conditions that the species can tolerate, the resources used and the methods used to obtain resources. © 2011 Pearson Education, Inc.
• Biotic Potential: rate species reproduce if unlimited. • Maximum growth rate given ideal conditions • Produces Exponential Growth • Modifying Factors • Birth Rate • Death Rate • Migration • Immigration – into an area • Emigration – out of an area © 2011 Pearson Education, Inc.
Exponential growth • Each species can increase its population • With favorable conditions • Exponential growth produces the J-curve: the curve of exponential growth © 2011 Pearson Education, Inc.
Exponential growth of a population • Under unlimited conditions, organisms will have rapid population growth • Carrying capacity (K): the maximum population of a species that a given habitat can support without being degraded • This is the upper limit of population growth © 2011 Pearson Education, Inc.
14 • Environmental Resistance Limits Population Growth • It decreases birth rate and increases death rate • Density – Dependent Factors • Predation • Parasitism • Competition • Density – Independent Factors • Weather, pesticides, pollutants, ect. © 2011 Pearson Education, Inc.
Density dependence and independence • Density-dependent factor: increases with increased population density • Predation, disease, food shortage • Logistic growth occurs when populations become more crowded (approach carrying capacity) • Density-independent factor: one whose effects are independent of the density of the population • Spring freeze, fire • Is not involved in maintaining population equilibrium in the logistic growth © 2011 Pearson Education, Inc.
Environmental resistance • Abiotic and biotic factors cause mortality (death) • Prevents unlimited population growth • Environmental resistance: the biotic and abiotic factors that may limit a population’s increase • Biotic: predators, parasites, competitors, lack of food • Abiotic: unusual temperatures, moisture, light, salinity, p. H, lack of nutrients, fire • Environmental resistance can also lower reproduction • Loss of suitable habitat, pollution • Changed migratory habits of animals © 2011 Pearson Education, Inc.
• Environmental Resistance : • Causes populations to stabilize at or below Carrying Capacity • Maximum population size an area can support • Limitations on population growth is necessary Note: Due to environmental resistance, growth levels off and we get a population growth pattern called Logistic Growth (s-shape curve) © 2011 Pearson Education, Inc.
Outcomes of population increase • Logistic growth: some process slows growth so it levels off near carrying capacity • Results in an S-shaped curve • It levels off at K • As the population approaches K, growth slows • The population remains steady and growth = 0 • The maximum rate of population growth occurs halfway to K © 2011 Pearson Education, Inc.
Populations show logistic growth • J-shaped explosions are often followed by crashes • J-shaped growth results from unusual disturbances • Introduction of a foreign species, a suddenly changed habitat, the elimination of a predator, arrival in a new habitat • Other populations show an S-curve • Followed by cycles of lower and higher numbers around K • Or shoot above K, eventually cycling around K © 2011 Pearson Education, Inc.
Three models of population growth © 2011 Pearson Education, Inc.
© 2011 Pearson Education, Inc.
22 40 Chapter The S-Curve of Population Growth (environmental resistance) Number of Individuals Carrying Capacity (biotic potential) Equilibrium Exponential Growth Time © 2011 Pearson Education, Inc.
• Species and Community Interactions: • Ecological niche: organisms habitat • No two species ever occupy exactly the same niche • Niches of different species will overlap • What effects the balance of a community of species • Competition • Predation • Symbiosis © 2011 Pearson Education, Inc.
• Competition • Intraspecific competition: competition between the same species helps control population size • Interspecific competition: competition between different species. • Competitive exclusion: no two species occupy the same niche • Resource partitioning—similar species live and feed in different areas © 2011 Pearson Education, Inc.
Resource Partitioning © 2011 Pearson Education, Inc.
Community Interactions • Predation: one organisms kills and eats another • Symbiosis—a close Interaction between Different Species Types of symbiosis: • Parasitism—one organism (parasite) lives on or inside another (host), harmful relationship (ex. Tapeworm) • Commensalism—one benefits, other is neither harmed nor benefits (ex. barnacles attached to whales) • Mutualism—relationship benefits both species (ex. Flowers and insects) © 2011 Pearson Education, Inc.
Predators Help Control Prey Populations 27 40 Chapter © 2011 Pearson Education, Inc.
Population Cycles in Predators and Prey 28 40 Chapter © 2011 Pearson Education, Inc.
Reproductive strategies: r-strategists • The interplay of environmental resistance and biotic potential drives the success of two reproductive strategies • r-strategists (r-selected species): produce lots of young, but leave their survival to nature • • • Results in low recruitment Rapid reproduction, rapid movement, short life span Adapted to a rapidly changing environment “Boom-and-bust” populations “Weedy” or “opportunistic” species For example, housefly © 2011 Pearson Education, Inc.
Reproductive strategies: K-strategists • K-strategists (K-selected species): lower biotic potential • Care for and protect young • Live in a stable environment already populated by the species • Larger, longer lived, well-adapted to normal environmental fluctuations • Their populations fluctuate around carrying capacity • Also called equilibrial species • For example, elephant, California condor © 2011 Pearson Education, Inc.
Life histories • Life history: progression of changes in an organism’s life • Age at first reproduction, length of life, etc. • Visualized in a survivorship graph • Type I survivorship: low mortality in early life • Most live the bulk of their life span (e. g. , humans) • Type III survivorship: many offspring that die young • Few live to the end of their life (oysters, dandelions) • Type II survivorship: intermediate survivorship pattern (squirrels, coral) • K-strategists have a Type I pattern; r-strategists show Type III © 2011 Pearson Education, Inc.
Survivorship curves © 2011 Pearson Education, Inc.
Succession: • Succession: Predictable changes in a community over time, usually as a result of a natural disturbance or human caused disturbance • Existing community is gradually replaced by another community over time Example: volcanic island arises from the sea with no living community – Bare rock © 2011 Pearson Education, Inc.
Succession: Predictable Sequence of Community Changes • Primary succession—bare rock, barren environments • No previously established ecosystems (ex. Volcanic island arises from sea) • Occurs over a longer period of time (thousands of years) • Pioneer species: lichens – break down rock to soil->Mossgrasses-> shrubs-> trees • Climax community – stable collection of organisms • Secondary succession—occurs in a disturbed, established ecosystem • Plowed field, timbered forest, after mining, fires, etc. • Occurs over shorter time (hundreds of years) © 2011 Pearson Education, Inc.
Succession in Progress Mount St. Helens explosion, 1980 Same view, 20 y later © 2011 Pearson Education, Inc.
Primary Succession 36 40 Chapter © 2011 Pearson Education, Inc.
Secondary Succession 37 40 Chapter © 2011 Pearson Education, Inc.
Succession in a Freshwater Pond (c) (a) (b) © 2011 Pearson Education, Inc.
- Chapter 4 section 1 population dynamics
- Population ecology section 1 population dynamics answer key
- Population ecology section 1 population dynamics
- Chapter 4 population ecology answer key
- Logistic growth ecology definition
- The concept of population
- Organismal ecology
- Population vs community ecology
- Concept 3 population ecology
- Chapter 53 population ecology
- Equilibrial life history
- Ecology
- Lynx and hare relationship
- Chapter 53 population ecology
- Characteristic of population
- Section 1 population dynamics answer key
- Population characteristics ecology
- What is population ecology
- Population definition ecology
- Population distribution
- Parasitism pictures
- Chapter 53 population ecology
- Unit 10, unit 10 review tests, unit 10 general test
- Sample
- Intention to treat analysis
- Whats a density independent factor
- Ecology study guide
- Section 1 community ecology
- Ecology is the study that helps to preserve
- Hình ảnh bộ gõ cơ thể búng tay
- Ng-html
- Bổ thể
- Tỉ lệ cơ thể trẻ em
- Chó sói
- Thang điểm glasgow
- Chúa yêu trần thế
- Môn thể thao bắt đầu bằng từ chạy
- Thế nào là hệ số cao nhất
- Các châu lục và đại dương trên thế giới