Chapter 3 The Biosphere

3.1 Vocabulary Biosphere Species Population Community Ecology Ecosystem Biome Biotic Factor Abiotic Factor

Section 1 What is Ecology? Standards: 6A.1 Objectives: Explain the difference between abiotic factors and biotic factors. Describe the levels of biological organization.

Biosphere Biosphere – consists of all life on Earth Earth  “Ball of Life” Includes land, water, and atmosphere

Ecology Ecology – study of the relationships among living organisms and the interaction the organisms have with their environment. Studying organisms in the field can be difficult  too many variables to study.

Living & Nonliving Factors Environmental conditions include biotic and abiotic factors: Biotic Factors – living organisms  (dead or alive) Abiotic Factors – nonliving parts  (physical components such as temperature, air, water, wind, humidity, sun, soil, rain, nutrients) Organisms depend on biotic & abiotic factors for survival. Organisms are well adapted to the biotic & abiotic factors in their environment ONLY.

Biotic and Abiotic Factors Environment Biotic Abiotic

Review: Biotic or Abiotic Factors?

Levels of Organization Biosphere is too large and complex to study relationships  ecologists study smaller levels. Organism  lowest level Population Community Ecosystem Biome Biosphere  highest level Least Complex Most Complex

Organism An individual living thing.

Population Population – group of the same species that share the same geographic location at the same time. Same species compete for same resources

Community Community – groups of interacting populations that occupy the same area at the same time.

Ecosystem Ecosystem – community of interacting organisms and the abiotic factors that affect them. No clear boundaries  overlap Changes in climate, migration, human activity  impact stability of ecosystem Stable Ecosystem = Healthy  Homeostasis: Population of each organism & supply of resources fluctuates at a predictable rate Constant flow of energy

Biome Biome – group of ecosystems that share the same climate and have similar types of communities. Examples: rainforest, desert, tundra, freshwater, marine

Review: Level of Organization B C D E F Biome Community Organism Biosphere Ecosystem Population

Ecological Methods Ecologists use 3 methods in their work: Observation Experimentation Modeling

3.2 Vocabulary Autotroph Carnivore Primary Producer Herbivore Photosynthesis Scavenger Chemosynthesis Omnivore Heterotroph Decomposer Consumer Detritivore

Section 2 Energy, Producers, and Consumers Standards: 3A.2, 6B.1 Objectives: Identify the ultimate energy source for photosynthetic producers. Classify organisms as producers, consumers, herbivores, scavengers, omnivores, decomposers, or detritivores.

Review All organisms need ENERGY. Energy is the ability to do work. Energy is needed for growth, reproduction, and other metabolic processes. Organisms do NOT create energy  organisms use energy from other sources. Ultimate source of energy  SUN

Energy from the Sun Autotrophs – organisms that collect energy from sunlight (or inorganic substances) to produce food. Also called PRIMARY PRODUCERS (first producers) Photosynthesis – captures light energy and uses it to power chemical reactions that convert carbon dioxide and water into oxygen and energy-rich carbohydrates (sugars and starches) Used by plants, algae, phytoplankton, some bacteria Adds oxygen to atmosphere and removes carbon dioxide

Energy Without the Sun Chemosynthesis – chemical energy is used by to produce carbohydrates Used by bacteria in deep-sea volcanic vents or hot springs

Energy from Consuming Heterotrophs – organisms that get energy by consuming other organisms. Also called CONSUMERS. Predator-Prey Relationship Examples: animals, fungus, bacteria Different types based on what they eat. Use sun indirectly

Types of Consumers Herbivores – eat only plants Examples: cow, rabbit, grasshopper Carnivores – eat only meat (or animals) Examples: lion, wolf, cat Omnivores – eat both plants and animals Examples: bears, humans Detritivores – eat dead plants & animals; recycles nutrients; decomposers Examples: worms, fungus

Types of Heterotrophs Herbivores Omnivores Carnivores Insectivores

3.3 Vocabulary Food Chain Phytoplankton Food Web Zooplankton Trophic Level Ecological Pyramid Biomass

Section 3 Energy Flow in Ecosystems Standards: 6B.1 Objectives: Describe the flow of energy through an ecosystem. Model the flow of energy through an ecosystem by creating a food chain or food web.

Energy Flow The sun’s energy enters Earth’s ecosystems through photosynthetic organisms  plants & algae. 1st Trophic Level Autotrophs/Primary Producers 3rd Trophic Level Carnivores & Omnivores/ Heterotrophs/Secondary Consumers 2nd Trophic Level Heterotrophs/Primary Consumers/Herbivores Tertiary Consumer Direction that Energy Flows

Models of Energy Flow Diagrams show the direction energy goes between organisms. Trophic Level – each step in a food chain or food web. Types of Models: Food Chain Food Web Energy Pyramid

Food Chain Food Chain – series of simple steps in which organisms transfer energy by eating & being eaten. Aquatic Ecosystems: Phytoplankton – photosynthetic algae  ocean surface Zooplankton – small free-floating animals

Food Web Most organisms feed on more than one species. Food Web – network of complex interactions formed by the feeding relationships among the various organisms in an ecosystem More accurate

Food Web

Food Web

Food Web

Food Web Disturbances If krill population drops, HOW would that affect the sizes of other populations?

Decomposers & Primary Producers

Ecological Pyramids Ecological Pyramids - shows the relative amount of energy, biomass, or numbers of organisms at each trophic level in an ecosystem. 90% of energy is utilized by organisms for cellular processes (respiration, movement, growth, etc.) and/or released back into the environment as heat. 10% of energy is available for the next trophic level.

Ecological Pyramids 3 Types: Energy, Population Size, & Biomass (total mass of living organisms in a trophic level) Base represents producers and size decreases in higher trophic levels.

3.4 Vocabulary Biogeochemical Cycle Nutrient Nitrogen Fixation Denitrification

Section 4 Cycles of Matter Standards: 3A.2, 6B.1 Objectives: Describe how nutrients move through the biotic and abiotic parts of an ecosystem. Explain the importance of nutrients to living organisms. Compare the biogeochemical cycles of nutrients.

Cycling of Matter Nutrients – chemical substances needed to live. Living organisms need specific nutrients to survive. Organisms composed mostly of 4 elements: carbon (C), hydrogen (H), oxygen (O), nitrogen (N). Earth  closed system Matter changes form but neither created nor destroyed  recycled in biosphere. Nutrients found in food, water, rocks, soil, air.

Cycling of Matter Biogeochemical Cycle – exchange of matter through the biosphere. Elements pass from one organism to another and among parts of the biosphere. 4 Biogeochemical Cycles Hydrologic Cycle (Water Cycle) Carbon Cycle Nitrogen Cycle Phosphorus Cycle

Water Cycle Life needs water Water is found in the atmosphere, Earth’s surface & underground, & in living organisms. Evaporation – sun’s energy changes liquid  gas Transpiration – evaporation of water from plants Condensation – cold temps. changes gas  liquid Precipitation – liquid water falls from sky Respiration –organisms produce water Elimination – organisms need water to eliminate waste

Water Cycle

Carbon Cycle Life needs carbon  macromolecules (lipids, carbohydrates, proteins, nucleic acids). Carbon is found in the atmosphere, minerals & rocks, fossil fuels, soil, & aquatic sediments. Organisms play a major role in recycling: Photosynthesis – plants take in CO2  sugar Respiration – organisms break down sugar  CO2 Decomposition – decomposers break down carbon compounds when organisms die  CO2 Digestion - Producers  Consumers  CO2 Combustion – burning wood/fossil fuels  CO2 Weathering – bones & shells form rocks  CO2

Carbon Cycle

Nitrogen Cycle Life needs nitrogen  make proteins & nucleic acids. Nitrogen is found in the atmosphere (N2), living organisms, soil, & aquatic sediments. Organisms play a major role in recycling: Nitrogen-Fixation – nitrogen-fixing bacteria found in soil, plant roots, or aquatic ecosystems convert nitrogen into usable forms for plants such as ammonia or nitrates. Decomposition – decomposers return nitrogen into soil. Denitrification – soil bacteria break down nitrogen compounds in soil & release N2 back into atmosphere.

Nitrogen Cycle

Phosphorus Cycle Life needs phosphorus  DNA & RNA P does not cycle in atmosphere. P is found in minerals & rocks, soil, & aquatic sediments. Organisms play a major role in recycling: Weathering of rocks & sediments  releases P Plants take in P  absorb from soil or water Decomposition – decomposers break down P compounds when organisms die Digestion - Producers  Consumers P is mined  produce fertilizer for crops

Phosphorus Cycle