Chapter 4: Ecosystems, Ecology, and Food Webs Doug Friedman, Jane Beiner, Shayna Benavidez

Article I: Ecology & Life

Ecology Ecology in Greek is “house or place to live” Study between organisms & their environment Examining how organisms interact with their environment

Organisms Forms of Life which can be classified into species 5-100 million species, most are insects and microorganisms About 1.8 million named

Wild & Domesticated Species A species that lives in its natural environment (where it’s ancestors lived) Domestic A species that was removed from its natural environment and placed in an environment that supports the needs and wants of HUMANS

Some Words to Know Populations Genetic Diversity Habitat Organisms that are part of the same species and live in the same area of space Genetic Diversity Each different organism has a different genetic make-up Habitat The place where a population lives. Each one can very in size and place. Biological Community A population that consists of a variety of species that live in a particular place. Use Overhead fig 4-2

One more Word Ecosystem A community of different species interacting with other species & their non-living environment Natural or Artificial

LIFE! Living things are made up of one or more calls containing DNA DNA is the instructions for making new cells and amino acids Metabolism Chemical reaction that capture and transform matter and energy from the environment to supply the organism

More LIFE Homeostasis Reproduction Maintains optimal conditions despite changes to the environment Reproduction Asexual Single cell division, or self fertilization Sexual Organisms exchange gametes and fertilize the ova to create offspring.

Article II: Earth’s Life-Support Systems

Layers Core Mantle Crust Fe and Trace N Solid & Liquid Fe, Si, O, Mg Solid and Liquid Responsible for continental drift Crust Fossil Fuels Where we life

Spheres Lithosphere Atmosphere Bio-Ecosphere Upper mantle and crust Thin envelope of air around the lithosphere Bio-Ecosphere Biotic and Abiotic Habitats

What is Needed to Sustain Life? One way flow of energy EX: Sunlight through feeding cycles, then into environment and eventually back out as infrared rays Cycle of Matter and Nutrients Gravity

Cycles Carbon Phosphorus Nitrogen Water Oxygen CO2 from the atmosphere and earth’s water. PHOTOSYNTHESIS Phosphorus DNA transfers Nitrogen Atmospheric N to the soil, helps with amino acids Water Storage, evaporation, precipitation, runoff Oxygen

Open or Closed? Closed Open ENERGY is exchanged with the environment (earth) Open ENERGY and MATTER is exchanged with the environment (animals)

The Sun Photosynthesis Earth gets 1 billionth of the sun’s energy CO2 + H2O + sunlight  C6H12O6 + O2 Earth gets 1 billionth of the sun’s energy 28% is reflected into space .023% gets absorbed by plants

Article III: Ecosystem Concepts

Intro Biomes Basic Zones Large Regions Characterized by features Land Ecotone (transition) Aquatic

Components of an Ecosystem “tics” Biotic Living part of ecosystem Abiotic Non-living part of ecosystem

ABIOTIC Examples Air Water Nutrients Solar Energy Precipitation Wind Altitude Latitude Frequency of Fire Nature of Soil Water Currents Concentrations

Laws and Factors Limiting Factor Principle Law of Tolerance The existence, abundance, and distribution of a species in an ecosystem are determined by whether the levels of one or more physical or chemical factors fall within the range tolerated by that species Limiting Factor Principle Too much or too little of any abiotic factor can prevent growth of a species

BIOTIC Autotrophs-Producers Heterotrophs-Consumers Photosynthesis Chemosysthesis Heterotrophs-Consumers Herbivores-Primary Carnivores-Secondary-Tertiary Scavengers eat already dead animals

Continued Decomposers Break down dead organisms into nutrients Detritivors eat dead animals Bacteria Fungi

GOAL OF ALL PRODUCERS & CONSUMERS Aerobic Respiration C6H12O6 + O2  CO2 + H2O +ENERGY

Article IV: Food Webs and Energy Flow in Ecosystems

A few Definitions Trophic Level Biomass Feeding level Dry weight which is not counted with water because water is not a source of energy Only small amounts of what is eaten is actually converted into biomass

ENERGY Some energy is lost from trophic level to trophic level 5-20% of energy is transferred from level to level The more trophic levels the greater cumulative loss of flow (pyramid of energy flow) The energy flow triangle shows earth could support more people if we ate grains instead of grazing animals

ENERGY (ct’d) There energy loss is so large we can only support 4-5 trophic levels Gross Primary Productivity (GPP): The rate it takes ecosystems to convert solar energy into chemical energy as biomass Net Primary Productivity (NPP): It is what is left of the biomass after the organism has used parts of it to stay alive, and reproduce

ENERGY (ct’d) NPP is available to other organisms as food The earth’s total NPP is the upper limit determining the planets carrying capacity for all species Most Productivity: Estuaries Swamps Marshes Tropical Rain Forest

ENERGY (ct’d) Least Productive: Open Ocean Tundra Desert 59% of NPP from Land, 41% of NPP from Water Open ocean contributes a lot to NPP but phytoplankton is not reasonably harvestable HUMANS waste 27% of potential NPP and 40% of actual

TATS ALL