Chapter 4: Ecosystems: Components, Energy Flow and Matter Cycling

I. What is Ecology? The Study of how Organisms interact with one another… and How they interact with their non-living environment

Organization on the Planet Fig. 4.2, p. 72 Ecosystem Organization: 1. Organism: Any Living thing 2. Population: Group of interacting Individuals of the same species Biosphere Ecosystems Communities Populations Organisms

3. Community: Populations of all the different species occupy a particular place 4. Ecosystem: Community of different species interacting with one another 5. Biosphere: All of the Earth’s Ecosystems

II. Biomes and Aquatic Life Systems A. Biomes:  Land portion of the biosphere  Distinct climate and specific life-forms adapted for life within that climate. Climate - long-term patterns of weather is the primary factor determining the type of life B. Aquatic life zones:  Marine and Freshwater

15,000 ft 10,000 ft 5,000 ft Coastal mountain ranges Sierra Nevada Mountain Great American Desert Rocky Mountains Great Plains Mississippi River Valley Appalachian Mountains Coastal chaparral and scrub Desert Coniferous forest Coniferous forest Prairie grassland Deciduous forest Average annual precipitaion cm (40-50 in.) cm (30-40 in.) cm (20-30 in.) cm (10-20 in.) below 25 cm (0-10 in.) Ecosystem Concepts and Components Fig. 4.9, p. 76

C. Ecotone Transitional zone between two ecosystems A mixture of species found in both ecosystems as well as organisms that are unique to the ecotones.

Ecosystem Boundaries: Ecotones Land zoneTransition zoneAquatic zone Number of species Species in land zone Species in aquatic zone Species in transition zone only Fig. 4.10, p. 77

III. COMPONENTS OF AN ECOSYSTEM 1.ABIOTIC – Non-living components (Water, air, nutrients and solar energy) 2. BIOTIC – Living components (Plants, animals, microorganisms)

1. Abiotic Ecological Factors RANGE OF TOLERANCE -Each population within an ecosystem has a RANGE OF TOLERANCE to abiotic factors

Population size LowHighTemperature Zone of intolerance Zone of physiological stress Optimum range Zone of physiological stress Zone of intolerance No organisms Few organisms Lower limit of tolerance Abundance of organisms Few organisms No organisms Upper limit of tolerance

A. Range of Tolerance: Minimum and maximum Range in which physical and chemical variations can be tolerated Individuals in a population may have different levels of tolerance Due to genetics, health and age Most susceptible during juvenile and reproductive stages

B. Limiting Factor The one factor that is most important in regulating population size Limiting Factor Principle: Too much or too little of any abiotic factor can limit a population

Water currents Dissolved nutrient concentration (O,N,P) Salinity Suspended solids Sunlight Temperature Precipitation Wind Altitude Fire frequency Soil ABIOTIC FACTORS

2. Main BIOTIC factors within an ecosystem METABOLISM. -All the living organisms sustain their existence by the process of METABOLISM. -2 Options: A.PRODUCERS – AUTOTROPHS A. PRODUCERS – AUTOTROPHS B. CONSUMERS - HETEROTROPHS B. CONSUMERS - HETEROTROPHS

A. AUTOTROPHS -Organisms that have the ability to make their own food PHOTOSYNTHESIS CHEMOSYNTHESIS

B. HETEROTROPHS  Primary consumer: (herbivore)  Secondary/Tertiary consumer: (carnivore)  Omnivore: Plants and Animals Organisms that have to get their food from other sources. Producer 1 consumer 2 Consumer 3

Detritivores and scavengers: Parts of dead organisms or their wastes Decomposers: Breakdown dead material (recycle)

AEROBIC RESPIRATION Process of using Oxygen to break down glucoseProcess of using Oxygen to break down glucose ANAEROBIC RESPIRATION Breaking down Glucose without OxygenBreaking down Glucose without Oxygen

Producers / Consumers

The Biotic Components of Ecosystems  Producers  Consumers  Decomposers Heat Abiotic chemicals (carbon dioxide, oxygen, nitrogen, minerals) Producers(plants)Decomposers (bacteria, fungus) Consumers(herbivores,carnivores) Solar energy

IV. Ecological Niches and Adaptation -NICHE: -The “role” that an organism plays in an ecosystem HABITAT -HABITAT the actual physical location where a species lives. -Two main types of Niches… A. Generalist B. Specialist

A. Generalist Species: Broad niches Ex: Flies, cockroaches, mice, rats, white-tailed deer, raccoons, channel catfish and humans B. Specialists: Narrow niches Ex: Spotted Owls, Giant Panda Bear

Is it better to be a generalist or a specialist? Benefits to specialists: If conditions are constant there is fewer competitors Benefits to generalists: Can adapt easier if the conditions are rapidly changing

Region of niche overlap Generalist species with a broad niche Generalist species with a narrow niche Number of individuals Niche separation Niche breadth Resource use Generalist Species vs. Specialist Species

Fundamental vs. Realized Niche Fundamental Niche: Full potential range of conditions Realized Niche: Occupies part of the fundamental niche to avoid competition

V. ENERGY TRANSFER: A.Food Chains, Webs, and Trophic Levels 1. Food Chain 1. Food Chain – Sequence of organisms, each of which is a food source for the next. *Shows how energy and nutrients move from one organism to another through the ecosystem.

2. Food Web 2. Food Web- -A complex network of interconnecting food chains showing the relationship of many organisms within an ecosystem. 3. Energy Pyramid/Trophic Levels 3. Energy Pyramid/Trophic Levels- A step in the transfer of energy through an ecosystem The level of a food chain that an organism occupies.

ENVIRO ENERGY

B. Biomass and Energy Flow Each level contains a certain amount of biomass: The dry weight of all organic matter in an organism. 1.) Only a small % of what is eaten is converted into biomass 2.) The amount of usable energy decreases at each trophic level

Heat First Trophic Level Second Trophic Level Third Trophic Level Fourth Trophic Level Solar energy Producers (plants) Primary consumers (herbivores) Tertiary consumers (top carnivores) Secondary consumers (carnivores) Detritvores (decomposers and detritus feeders)

FOOD CHAINS AND WEBS

Ecological Efficiency: % of usable energy transferred from level to level Typically 5-20% Pyramid of Energy Flow Explains why: 1.) So few top carnivores 2.) Why these species are the first to suffer when there is disruption 3.) Why they are vulnerable to extinction

Ecological Pyramids Heat ,000 10,000 Usable energy Available at Each tropic level (in kilocalories) Producers(phytoplankton) Primary consumers (zooplankton) Secondary consumers (perch) Tertiary consumers (human) Decomposers

Pyramids of Biomass and Numbers Storage of biomass at each level Organisms are sorted, dried and weighed Most land ecosystems have a reduction in biomass at each level There may be more primary consumers in an open ocean Photoplankon is small and is eaten as soon as it is produced

VI. Primary Productivity of Ecosystems  Gross primary productivity (GPP)  Net primary productivity (NPP) Estuaries Swamps and marshes Tropical rain forest Temperate forest Northern coniferous forest (taiga) Savanna Agricultural land Woodland and shrubland Temperate grassland Lakes and streams Continental shelf Open ocean Tundra (arctic and alpine) Desert scrub Extreme desert 8001,6002,4003,2004,0004,8005,6006,4007,2008,0008,8009,600 Average net primary productivity (kcal/m 2 /yr) Fig. 4.25, p. 88

 Gross Primary Productivity (GPP): Rate that producers convert solar energy into biomass Usually greatest in: Shallow Waters Coral Reefs (abundant light, heat and nutrients) Upwellings (Currents bring up nutrients from the ocean bottoms) Least in: Deserts Open ocean

Net Primary Productivity: Producers must use some of the total biomass they produce for respiration NPP is what is left as available food. Net Primary Productivity = Energy stored - Energy used (Photosynthesis) - (Respiration)

Why Not Use the Most Productive Regions to Feed the Human Population? Most swamp/marsh foods are not fit for human consumption Most of the nutrient of a tropical forest are stored in the vegetation Energy requirements of harvesting food from the oceans are too high It would deplete vital sources of food for other forms of life and alter the food webs

How much of the Worlds Net Biomass Do we Use? Humans have taken over a degraded 73% of the Earth’s land surface Humans use, waste or destroy 40% of the net primary productivity What may happen if the human population doubles over the next years?