Levels of Organization

Levels of Organization What are the levels from smallest to largest? 1 Species: can breed and produce fertile offspring Population: same species in same area Community: different populations in same area Ecosystem: all organisms in particular place; includes nonliving surroundings Biome: group of ecosystems with same climate and similar communities Biosphere: all portions of the planet where life exists (land, water, air, atmosphere)

Ecology—the scientific study of interactions between different organisms and between organisms and their environment or surroundings 2

Biotic—living factors that influence an ecosystem 3 Abiotic—non-living factors that influence an ecosystem

Producers A. Sunlight is the main energy source for life on earth Also called autotrophs C. Use light or chemical energy to make food 1. Plants 2. plant-like protists (algae) 3. Bacteria 4

(Remember: 6CO2 + 6H2O 6O2 + C6H12O6) D. Photosynthesis—use light energy to convert carbon dioxide and water into oxygen and carbohydrates (Remember: 6CO2 + 6H2O 6O2 + C6H12O6) E. Chemosynthesis—performed by bacteria, use chemical energy to produce carbohydrates Light Energy 5

B. Also called heterotrophs Consumers Organisms that rely on other organisms for their energy and food supply B. Also called heterotrophs 6

Herbivores—obtain energy by eating only producers 7 Carnivores—eat only consumers

Omnivores—eat both producers and consumers 8 Decomposers—breaks down dead organic matter

Feeding Interactions A. Energy flows through an ecosystem in one direction—from the sun or inorganic compounds to autotrophs (producers) and then to heterotrophs (consumers) 9

Arrows go in the direction of how energy is transferred 10 Food Chain—series of steps in which organisms transfer energy by eating and being eaten Arrows go in the direction of how energy is transferred Start with producer and end with top consumer or carnivore Ex: grass cricket frog raccoon

C. Food Web—network of food chains within an ecosystem 11 Hawks Weasels Raccoons Mice Grass Grass Which of the organisms above is the producer? Which of the organisms above is the top consumer? Hawks

Trophic Levels—each step in a food chain or food web 1. Level 1—Producers (autotrophs) 2. Level 2—Primary Consumers (herbivores) 3. Level 3—Secondary Consumers (carnivores or omnivores) 4. Level 4—Tertiary Consumers (carnivore—usually top carnivore) 12

Hawks Weasels Raccoons Mice Grass Food Webs 13

14 Ecological Pyramids A. Diagram that shows the relative amount of energy or organisms contained within each trophic level of a food chain or web

15 Energy Pyramid shows relative amount of energy available at each trophic level 1. Organisms in a trophic level use the available energy for life processes (such as growth, photosynthesis, cellular respiration, metabolism, etc.)and release some energy as heat Remember: Every chemical process that happens in your body releases heat as a byproduct (ex: burning calories). 2. Rule of 10—only about 10% of the available energy within a trophic level is transferred to the next higher trophic level C. Biomass Pyramid—represents the amount of living organic matter at each trophic level

100% 10% 1% 0.1% Energy Pyramid Biomass Pyramid

Energy and Biomass Pyramid (together) Represents amount of energy available at each level as well as amount of living tissue—both decrease with each increasing trophic level

Heavy metals Ex: mercury Pesticides Ex: DDT (dichlorodiphenyltrichloroethane) Organochlorides: Ex: PCBs

V. Ecological Interactions between organisms Competition—when two organisms of the same or different species attempt to use an ecological resource in the same place at the same time. Ex: food, water, shelter

Monkeys compete with each other and other animals for food. Rams compete with each other for mates.

Until Americans introduced gray squirrels into parts of England in the early 20th century, red squirrels had been the only species of squirrel in the country. The gray squirrels were larger and bred faster and successfully competed for resources. Within a couple years of overlap in an area, the red squirrels disappeared.

B. Niche—the ecological niche involves both the B. Niche—the ecological niche involves both the place where an organism lives and the roles that an organism has in its habitat. Example: The ecological niche of a sunflower growing in the backyard includes absorbing light, water and nutrients (for photosynthesis), providing shelter and food for other organisms (e.g. bees, ants, etc.), and giving off oxygen into the atmosphere.

“Address”—Soil, Ground, etc. The ecological niche of an organism depends not only on where it lives but also on what it does. By analogy, it may be said that the habitat is the organism’s “address”, and the niche is its “profession”, biologically speaking. “Address”—Soil, Ground, etc. Worm’s Niche “Profession”– Mix-up soil

C. Predation—one organism captures and feeds on another organism 1. Predator—one that does the killing 2. Prey—one that is the food

1. Mutualism—both species benefit (WIN-WIN) a. Ex: insects and flowers D. Symbiosis—any relationship in which two species live closely together 1. Mutualism—both species benefit (WIN-WIN) a. Ex: insects and flowers Can you think of any other examples that we’ve talked about in class?

Example: barnacles on a whale 2. Commensalism—one member of the association benefits and the other is neither helped nor harmed. (WIN-0) Example: barnacles on a whale

Birds build nests in trees. The Remora fish attaches to the shark and gets a free ride. Commensalism Birds build nests in trees.

3. Parasitism—one organisms lives on or inside another organism (host) and harms it. The parasite obtains all or part of its nutritional needs from the host. (WIN-LOSE) Example: fleas on a dog

Parasitism Wasp eggs on back of caterpillar. Sea lampreys feed on fluids of other fish. Mosquito biting a human.

Mutualism, Commensalism or Parasitism??

Tropisms Plants have adapted to survive in their environments over time. Some of the ways we call tropisms – Thigmotropism – grow by touch (ex. Vines) Phototropism – grow towards the light (ex. A sunflower bending towards the light) Gravitropism – growing down because of gravity (ex. Root

What happens to a garden or field when plants are removed in the fall and not replanted in the spring?

Succession Succession- the series of changes that take place in a community; either as initial growth or new growth Link

Primary succession- growth in a lifeless area, soil not yet formed Ex: new volcanic island/the land under a retreating glacier Lichen and mosses will grow first and create small pockets of soil from which small grasses can grow

Secondary Succession- the regrowth of an existing community after a disturbance that leaves the soil intact

Figure 53.18x2 Forest fire

Figure 53.18 Patchiness and recovery following a large-scale disturbance

Succession in a Pond- Eutrophication

Ecology Review

What is Ecology? Ecology is the study of interactions among organisms and between organisms and their environment. There are many levels of organization ecologists study…

Energy Flow Energy flows in Sun to producers (make own food) to levels of consumers (get food from other organisms) one direction

Energy Flow Producers: Autotrophs Consumers: Heterotrophs Photosynthesis Vs. Chemosynthesis Consumers: Heterotrophs Herbivores - eats only plants Carnivores – eats only other animals Omnivores – eat both Detritivores – eat remains of plants/animals Decomposers – break down dead organisms

Feeding Relationships Food chain: series of steps Food web: links all food chains together Trophic level: each step in a chain or web

Ecological Pyramids Energy Pyramid Shows the relative amount of energy available at each trophic level. Most of the energy at the bottom - plants Biomass Pyramid Represents the amount of living organic matter at each trophic level. Typically, the greatest biomass is at the base of the pyramid.

Recycling in the Biosphere Unlike the one-way flow of energy, matter is recycled. Matter moves through an ecosystem in biogeochemical cycles. Matter is recycled because systems do not use up matter, they transform it.

Nutrient Cycles Every organism needs nutrients to grow and function. Like water, nutrients are also transferred in cycles. 3 Nutrient Cycles: Carbon Nitrogen Phosphorus-mostly in rocks and soil minerals

Carbon Cycle CO2 in Atmosphere CO2 in Ocean

Nitrogen Cycle N2 in Atmosphere NO3- and NO2- NH3

Nitrogen Cycle Bacteria that live in the soil and on the roots of legume plants convert nitrogen gas to ammonia through nitrogen fixation. When organisms die, their ammonia can be converted back to nitrogen gas through denitrification.

How do humans impact their environment? Human Impact How do humans impact their environment?

Populations Some people say there are too many of us and the earth is overcrowded, but……. nobody wants to leave.

Growth of populations The growth rate of any population depends on the birth rate and the death rate. If the birth rate > death rate, then pop. will increase. If birth rate < death rate, pop. will decrease. If birth rate = death rate, then pop. stays the same.

J-Curve/Exponential Growth: shows growth under ideal conditions Unlimited resources: Plenty of food and space No disease No predators Favorable temperatures No such place exists; eventually resources will be limited

However, organisms under ideal conditions are said to reach their biotic potential: the highest rate of reproduction under ideal conditions

S-Curve/Logistic Growth: a typical population growth curve The first stage shows little pop. growth since there are few organisms to reproduce. A rapid increase follows due to plentiful food and few predators. The population growth eventually slows and stops. Controlled by limiting factors- circumstances which keep organisms from reaching their biotic potential Eventually the carrying capacity of this population will be reached

Carrying Capacity- the maximum number of organisms an environment can support The number of organisms tends to rise above and below the carrying capacity depending on the limiting factors that are present. Why is this beneficial? http://carrier.pbworks.com/f/carrying%20capacity.gif

Limiting Factor Examples Density-dependent (impact determined by population size) Food Water Space Predation Disease Density–independent (same effect regardless of population size) Temperature Natural Disaster Disease

Changes in a Population’s Size Births and immigration add individuals to a population. Births Immigration Population size Emigration Deaths Deaths and emigration remove individuals from a population. Immigration – The movement of individuals into a population from another population. Births – An increase in births increases the population size. Emigration – The movement of individuals out of a population into another population. Death – When individuals die, the population decreases.

Population Density Population Density is a measurement of the number of individuals living in a defined space.

Geographic Dispersion: Population Dispersion is the way in which individuals of a population are spread in an area or a volume. There are three types of population dispersion: 1. Clumped Dispersion – individuals may live close together in groups in order to facilitate mating, gain protection, or access food resources. 2. Uniform (even) Dispersion – Territoriality and intraspecies competition for limited resources lead to individuals living at specific distances from one another. 3. Random Dispersion – Individuals are spread randomly within an area or volume. They have almost no competition or predators. Important

Geographic Dispersion

Population Dispersion Patterns This is a highly social group of animals such as baboons which must live near a watering hole and food source. This is also the most common distribution found in nature. A. Uniform (even) dispersion B. Random dispersion C. Clumped dispersion C. Clumped dispersion

VIDEO ON CARRYING CAPACITY AND DISPERSION PATTERNS http://education-portal.com/academy/lesson/populations-growth-density-and-carrying-capacity.html VIDEO ON CARRYING CAPACITY AND DISPERSION PATTERNS

What part would be MOST affected by a Density Independent Limiting Factor 3 2 It is limiting no matter the size of the population 1

Human Impact can take several forms Resource Use Land abuse Pollution Loss of Biodiversity Ozone Depletion Greenhouse Effect Global Warming

Resource Use Whether a resource is “renewable" or “nonrenewable" is about how long nature takes to renew it. Renewable – can be renewed by nature, includes energy sources that do not consume fuel Renewable resources are NOT unlimited, they can be abused Plants, animals

Resource Use cont. Nonrenewable Resources – cannot be replenished by nature within our lifetimes - are limited in supply fossil fuels, metals, other minerals Sustainable Use – using natural resources at a rate that does not deplete them

Land Abuse Soil Erosion Desertification – farming and drought turn dry grasslands into desert Deforestation

Pollution Acid Rain - burning of fossil fuels release N2 & S which combine with water vapor to form nitric and sulfuric acid Acid Rain

Pollution – Biological Magnification Biological Magnification – concentration of harmful substances increase in organisms as chemical travel in the food web

Loss of Biodiversity Biodiversity is the variety of living things. CAUSES of Loss: Endangered species – species that is highly vulnerable to extinction Habitat loss – physical reduction in suitable places to live

Ozone Depletion layer of ozone (O3) is normally present in Earth’s upper atmosphere prevents much of UV light emitted by sun from reaching Earth’s surface Chlorofluorocarbons (CFCs) – in polar atmosphere, CFCs act as catalyst that enable UV light to break apart ozone materials

What does the Ozone Layer do? Ozone absorbs 99% of the harmful ultraviolet (UV) radiation. Without the Ozone Layer Most of the harmful UV radiation will penetrate the atmosphere. This can cause skin cancer and eye problems but DOES NOT cause Global Warming!

Greenhouse Effect heat is retained by the layer of gases (CO2, CH4, etc) forming the atmosphere. This is a Natural Process!

Global Warming Increase in average temperature of biosphere over past 120 years, global temp. has risen .5o C CAUSES – human activities have caused global warming by adding CO2 and other greenhouse gases to the atmosphere RESULT – atmospheric greenhouse gases retain more heat and average temp rises. Can cause sea level to rise and disrupt weather patterns

Population Review What factor listed below has NOT contributed to the explosive human growth seen in the last 100 years? Advancements in medicine. Improved sanitation. More available jobs. Global Warming 2. Which factor listed below is NOT considered scientific evidence for global warming? A. Data from retreating glaciers B. Average increase in global temp. C. Increase in storm intensities. D. Increased rate of extinction. D D

Population Review C D How many people currently live on planet Earth? A. 1 million B. 1 billion C. 7 billion D. 100 billion What is the carrying capacity for humans on planet Earth? A. 1 million B. 6 billion C. 100 billion D. unknown C D

Population Review 5. How are human populations NOT likely to be impacted by global warming? A. Frequent intense storms B. Rising power costs C. Rising sea levels D. Increased temperature B

Population Review 6. Why do humans need more potent pesticides over time? A. Because the target population soon develops a resistance to the chemical. B. Because pesticide salesman need to make more money. C. Because plants begin to eat the pesticides. D. Because the explosive growth of the human population places increased demands on current farmers. A

Population Review D 7. Where are pesticides found in the environment? A. In the soil only B. In the water only C. In the air only D. Everywhere D

Population Review 8. Which of the following activities requires the most commercially produced power? A. Heating a new home. B. Heating an old home. C. Heating a car. D. Building a fire. B

Population Review 9. Which of the following is an environmentally responsible water consumption technique? A. Washing your favorite outfit by itself in the washing machine. B. Watering your garden between 10 pm and 10 am. C. Leaving the hose running the entire time you wash your car. D. Taking 2 showers per day. B

Population Review 10. How much power in the U.S. is produced by fossil fuels? A. Under 40% B. About 50% C. Over 60% D. 100% C