Biology Ecology Chapters 2 5 Ecology Topics Essential

Biology Ecology Chapters 2 -5

Ecology Topics Essential Questions 1. What is ecology? What do ecologists study? • Introduction to Ecology 2. Compare and contrast biotic and abiotic factors. What is their importance in an ecosystem? • Abiotic & Biotic factors of an Ecosystem 3. Identify and describe the following symbiotic relationships: mutualism, commensalisms, and parasitism. 4. Describe the relationship of a predator to its prey. • • Predator/ Prey Relationships Symbiotic Relationships

Ecology – Key Terms • • • • Ecology Abiotic Biotic Population Community Ecosystem Habitat Niche Predator Prey Symbiosis Commensalism Parasitism Mutualism Organism Biosphere Organizing key terms: Organization Living v. nonliving Relationships Biosphere Biotic (living) Symbiosis: Mutualism (+/+) Commensalism (+/0) Parasitism (+/-) Abiotic (nonliving) Ecosystem Community Predator Prey Population Habitat (location) Organism (species) Niche (role / job)

What is Ecology? Ecology is the study of the interactions of living organisms with one another and with their nonliving environment of matter and energy; study of the structure and functions of nature What roles do insects play?

Ecosystem Organization Overview Biosphere- Zone of earth where life is found. Sometimes called the ecosphere Ecosystems- Community of different species interacting with one another and with the chemical and physical factors making up its nonliving environment Communities- Populations of all species living and interacting in an area at a particular time Populations- Group of individual organisms of the same species living in a particular area Organisms Any form of life (species)- group of organisms that resemble one another in appearance, behavior, chemical makeup and processes, and genetic structure.

What are the Characteristics of Life? Biotic – living components of an ecosystem Abiotic – Nonliving component of an ecosystem All things living have the following specific properties: Known species 1, 412, 000 Other animals 281, 000 ØCellular organization ØMetabolism ØHomeostasis ØReproduction Fungi 69, 000 Insects 751, 000 Prokaryotes 4, 800 ØHeredity About 1. 4 million species have been identified, but estimates of number of species range from 3. 6 million to 100 million Protists 57, 700 Plants 248, 400

Ecosystem Components The major components of ecosystems are abiotic (nonliving) water, air, nutrients, solar energy, and biotic (living) plants, animals, and microbes. Niche – How organisms interact with each other within a community. An organism role in the ecosystem Habitat is the place where a population or an individual organism usually lives

Major Biomes and the Role of Climate The amount of energy received and topography of a region determines climate. Terrestrial parts of the biosphere are classified as biomes, areas such as deserts, forests, and grasslands. Temperature, precipitation and topography (abiotic factors) determine the vegetation (plants) and the animals they will support Aquatic life zones describe the many different areas found in a water environment, such as freshwater or marine life zones (coral reefs, coastal estuaries, deep ocean).

Biomes of the World Polar Temperate Tropic of Cancer Equator Tropics Tropic of Capricorn Arctic tundra (polar grasslands) Desert Boreal forest (taiga), evergreen coniferous forest (e. g. , montane coniferous forest) Tropical rain forest, tropical evergreen forest Semidesert, arid grassland Mountains (complex zonation) Temperate deciduous forest Tropical deciduous forest Ice Temperate grassland Tropical scrub forest Dry woodlands and shrublands (chaparral) Tropical savanna, thorn forest

Tropical Rainforest Deserts Deciduous Forest

Tundra Grassland Taiga

Aquatic Life Zones-Marine and freshwater portions of the biosphere. Examples include freshwater life zones (such as lakes and streams) and ocean or marine life zones Open Sea level Depth in meters 0 50 Euphotic Zone Estuarine Zone 100 Continental shelf Photosynthesis Sun 200 500 Bathyal Zone 1, 000 Twilight High tide Low tide Coastal Zone 1, 500 Marine Life Zones 2, 000 3, 000 4, 000 5, 000 10, 000 Darkness Abyssal Zone

Relationships

Symbiotic Species Interactions: Mutualism (+/+) Pollination mutualism Insects Nutritional mutualism Hermit crabs and Anemones Monkeys and Deer Gut inhabitant mutualism Cellulose digesting protozoa Parasitism (+/-) Parasite – organisms feeding on or in another species Host – organisms fed on by parasites External parasites Internal parasites Commensalism (+/0) Species interaction that benefits one and has little or no effect on the other. Example: Small plants growing in shade of larger plants or Hermit crab and Rag worm Lifecycle of a Parasite Symbiosis Overview The head of the tapeworm is called a scolex, and is equipped with hooks and suckers which are used for attaching to the intestinal wall of the host. Adult tapeworms, some reaching a length of 15 feet, are parasites in the guts of animals and absorb nutrients across their body surface. The structures behind the head are called proglottids.

Species Interactions – Predation / prey Prey Acquisition Example: Killer Whales Predator Avoidance Camouflage Span worm Deceptive Behavior Wandering leaf insect When touched, the snake caterpillar changes shape to look like the head of a snake Deceptive Look Chemical Warfare Hind wings of Io moth resemble eyes of a much larger animal Poison dart frog Mimicry Bombardier beetle Foul-tasting monarch Butterfly Viceroy butterfly mimicsmonarch butterfly

Ecology Topics • • Ecosystem energy flow Essential Questions 5. Explain the ways in which energy flows through an ecosystem. 6. What role does the carbon cycle play in photosynthesis and cellular respiration? 7. How are communities influenced? What are the major limiting factors that influence carrying capacity? 8. What do population growth graphs look like? Can you identify them? Cycles in an ecosystem • Limiting Factors • Population Growth Graphs

Ecology – Key Terms • • • • Autotrophs / Producer Photosynthesis Heterotrophs / Consumer Cellular Respiration Decomposer / Consumer Food Chain Food Web Energy Pyramid Biomass Limiting Factor Biotic Potential Environmental Resistance Carrying Capacity Logistic Growth Exponential Growth

Natural Capital: Sustaining Life of Earth Flow of Energy to and from the Earth From the sun to the Earth Remote Sensing One-way flow of energy from Sun Cycling of Crucial Elements Gravity

Ecosystem Components Glucose and other organic compounds are broken down and energy released by the process of aerobic respiration, the use of oxygen to convert organic matter back to carbon dioxide and water. This process is a net chemical change to that of photosynthesis. Photosynthesis: CO 2 + H 2 O Carbon dioxide water CO 2 + H 2 O Light C 6 H 12 O 6 + O 2 Glucose sugar oxygen C 6 H 12 O 6 + O 2 Aerobic Respiration “Cellular Respiration” Some decomposers are able to break down organic compounds without using oxygen. This process is called anaerobic respiration, or fermentation. The end products are compounds such as methane gas, ethyl alcohol, acetic acid, and hydrogen sulfide. Matter is recycled; there is a one-way flow of energy.

Food Chains and Energy Flow in Ecosystems Food chains and food webs help us understand how eaters, the eaten, and the decomposed are interconnected in an ecosystem. The sequence of organisms as they are eaten is a food chain. Food webs are complex networks of interconnected food chains. They are maps of life's interdependence. Trophic levels are feeding levels for organisms within an ecosystem, (1) Producers belong to the first trophic level. (2) Primary consumers belong to the second trophic level. (3)Secondary consumers belong to the (4) third trophic level. Detritivores and decomposers process detritus from all trophic levels. Energy flow in a food web/chain decreases at each succeeding organism in a chain or web. The dry weight of all organic matter within the organisms of a food chain/web is called biomass.

Tropic Levels Humans Blue whale Ecological efficiency is the term that describes the percentage of usable energy transferred as biomass from one trophic level to another and ranges from 2%-40% with 10% being typical. Sperm whale Killer whale Elephant seal Crabeater seal Leopard seal The greater number of trophic levels in a food chain, the greater loss of usable energy. Emperor penguin Adélie penguins Petrel Squid Fish Carnivorous plankton Herbivorous zooplankton Krill Phytoplankton

Ecological Pyramids Pyramid of numbers Pyramid of energy flow Compares the total number of organism at each The pyramid of energy flow trophic level visualizes the loss of usable energy through a food chain. The lower levels of the trophic pyramid support more organisms. If people eat at a lower trophic level (fruits, vegetables, grains directly consumed), Earth can support more people. There is a large loss of energy between successive trophic levels. Pyramid of biomass Compares biomass (The dry weight of all organic matter within the organisms of a food chain/web) at each trophic level

Ecosystem Factors Ecosystem characteristics include a range of tolerance to physical and chemical environments by the ecosystem's populations Law of tolerance: The distribution of a species in an ecosystem is determined by the levels of one or more physical or chemical factors being within the range tolerated by that species. Aquatic life zones can be limited by the dissolved oxygen (DO) content in the water, temperature, p. H or by the salinity Sugar Maple The limiting factor principle states that too much or too little of any abiotic factor can limit or prevent growth of a population, even if all other factors are at or near the optimum range of tolerance. An abiotic factor such as lack of water or poor soil can be understood here

The Study of Population Dynamics Populations change in size, density, dispersion and age structure. Population density —the number of individuals of a population that inhabit a certain unit of land or water area. Population dispersion —refers to how individuals of a population are spaced within a region. Age structure of a population is usually described as the pre-reproductive stage, the reproductive stage and the postreproductive stage. A population with a large reproductive stage is likely to increase, while a population with a large post-reproductive stage is likely to decrease.

Population Size Four variables influence/govern population size: (1) births, (2) deaths, (3) immigration, and (4) emigration. Increase in population occurs by birth and immigration. Decrease in population occurs by death and emigration. Rapidly growing populations have four characteristics: 1. Individuals in the population reproduce early in life. 2. Individuals have short periods between generations. 3. Individuals have long reproductive lives. 4. Individuals produce multiple offspring each time they reproduce.

Biotic Potential vs. Environmental Resistance The biotic potential max (rmax) is the population's capacity for growth. The intrinsic rate of increase (r) is the rate of population growth with unlimited resources. environmental resistance consists of factors that limit population growth. limiting Factors No population can grow indefinitely due to limited resources such as light, water, and nutrients and also due to competitors and/or predators.

Limiting Factors Examples: Extrinsic Biotic – Density Dependent Abiotic – Density Independent Intrinsic Social Hierarchy Gender changing Density-independent population controls affect a population's size regardless of its density. These are abiotic factors in the community. Density-dependent factors or population controls have a greater affect on the population as its density increases. Infectious disease is an example of densitydependent population control.

Biotic Potential v. Environmental Resistance (Logistic Population Growth) Environmental resistance Population size (N) Carrying capacity (K) is determined by biotic potential and environmental resistance. (K) is is the number of a species individuals that can be sustained indefinitely in a specific space. Biotic potential Exponential growth Time (t) As a population reaches its carrying capacity, its growth rate will decrease because resources become more scarce.

The Role of Predation in Controlling Population Size Interactions between predators and their prey change in cycles and appear to be caused by species interactions, but other factors may be involved. The hypothesis of top-down control of prey by predators may not be the only explanation for the boom-andbust cycles seen in these populations. This may also be related to the food supply of prey. The bottom-up control hypothesis states that plants are consumed too rapidly by prey for replacement to keep up. This may lead to a crash of herbivores, and that may lead to a crash of higher predators. Fig. 9 -8 p. 168 These are not mutually exclusive hypotheses; more probably have interaction between predation and food supplies.

Ecology Topics • Human population growth • Biodiversity • Impacts on the environment • Factors influencing climate • Direct & Indirect influence on natural resources • Conservation Essential Questions 9. What factors affect the growth of human populations? 10. What is biodiversity? Describe the importance of it. 11. How do both the changes and the needs of a human populations impact the environment? 12. What are the factors that influence climate? 13. How do humans directly and indirect influence natural resources? What some practices that can be done to improve and conserve the natural world?

World Population and Exponential Growth “Rule of 70” Doubling Time As the human population grows what might be the impact on (1) resources use and waste (2) poverty (3) loss of biodiversity (4) Global Climate Change 2008

Living on interest vs. Living on principal Living on Interest (Sustainably) Imagine you win $1, 000 in the lottery Invest the capital (1 million) at 10% interest. You will have a sustainable income of $100, 000 per year. Without depleting your capital (1 million) Living on Principal If you spent $200, 000 per year, your 1 million would be gone early in the 7 th year If you spent $110, 000 per year, you would be bankrupt early in the 18 th year. How would you prefer to live? How do we live now?

Who is Overpopulated? Population Growth Are we living Sustainably? Is the problem we face population size or resource use? Fig. 1 -4, p. 8 return

Ecological Footprint What is an ecological footprint? Age of Consumption – Examples of over consumption

How have human activities affected the Earth’s biodiversity? Humans have disturbed from 50 to 83% of the earth's land surface. Humans use, waste, or destroy about 40% of the net primary productivity of the planet's terrestrial ecosystems. Planet in Peril – Battle lines (2009) Examples / Issues: Bush Meat / Zoonotic Viruses Nigerian Oil Conflict Peruvian Lead poisoning Shark fining and Ecotourism African Elephants Mountain Gorillas Planet in Peril (2007) Thailand Species Trade China and Cambodia

Why should we care about biodiversity? Preservation of biodiversity is important for several reasons, such as intrinsic or existence value, and also because of its usefulness to humans (Instrumental Value) Instrumental value consists of use values that benefit people for goods and services, scientific information, recreation, and ecological services. Nonuse values are (1) existence value, (2) aesthetic value (the appreciation of wild species, or a view for beauty alone), and (3) bequest value (the act of leaving natural capital for use by future generations). What is Conservation Biology? • Conservation biology is a multidisciplinary science that originated in the 1970’s. Its goal is to use emergency responses slow down the rate destruction and degradation Goals, strategies, and tactics for protecting biodiversity

Climate Change and Human Activities Ø Increased use of fossil fuels Ø Global warming Ø Melting icecaps and glaciers Planet in Peril – Sea Level Rise Ø Rising sea level Ø Deforestation

Factors Affecting the Earth’s Temperature Ø Changes in solar output Ø Changes in Earth’s albedo Ø Moderating effect of oceans Ø Clouds and water vapor Ø Air pollution

Greenhouse effect Ø Greenhouse gases

Loss of the Ozone Layer: Reasons for Concern Ø Increased incidence and severity of sunburn Ø Increase in eye cataracts Ø Increased incidence of skin cancer Ø Immune system suppression Ø Increase in acid deposition Ø Lower crop yields and decline in productivity Seasonal Ozone Layer Thinning at the Poles Ø Ozone thinning (hole) Ø Polar vortex Skin Cancer

Endangered planet 1990 State of the Planet 2007 The Lorax