CHAPTER 3: The BIOSPHERE 3-1 What is Ecology? 3-2 Energy Flow 3-3 Cycles of Matter
Ecology Study of the interactions of organisms with one another and with their physical surroundings.
Earth is a Living Planet Earth is a single living system. It is a biosphere.
A view of Earth from space A Central Park woodland Approaching Central Park (the red rectangle in the middle of this photo) An eastern gray squirrel Figure 1.2.1
A Hierarchy of Interactions Organismal ecology (individual) Population ecology (group of individuals) Community ecology (all organisms in a particular area) Ecosystem ecology (all organisms and abiotic factors)
Ecosystems consists of a given area’s physical features (______________) and living organisms (______________). abiotic factors biotic factors
B. ECOSYSTEM STRUCTURE 1. abiotic factors – ____________________ examples: __________________________ nonliving components water, light, heat, gases, minerals 2. Biotic factors – organisms transfer energy, participate in cycle of chemicals, change environment
Homework Due • Read Pgs. 62-65 (Sect. 3.1) • Section Assessment Quest. #1-5 on pg. 67 (stamp) Tonight’s homework: -Read pgs. 67-73 (Sect. 3.2) -Do Section Assessment Quest. #1-5 on pg. 73
Introductory Questions #6 1. A group of ecosystems that have the same climate & dominate communities are called _______. (see pg. 64) • At what biological levels does the study of Ecology include? (see Fig. 3-2) • Ecological research involves three fundamental approaches. Name these three approaches. (see Fig. 3-3, pg. 65) • What is the main energy source for all life? (see pg. 67) • Explain how an autotroph is different from a heterotroph. Give three examples for each. (see pgs. 67-68)
Biotic Factors Living aspects of an ecosystem such as_____________ _______________, worms, amoebas, and waterlilies. fishes, frogs, insects, snails,
Habitats • the location or surrounding where the organism lives
Community organisms living together in an ecosystem
Niches the behavior of organisms in their habitats.
Abiotic factors nonliving physical parts of an ecosystem such as _______________ type, rocks, temperature, _______________, and rainfall. water, sunlight, soil humidity, elevation Wind: Can affect the pattern of a plant’s growth
Abiotic Factors Temperature Sunlight Water & precipitation Wind Rocks & Soil Climate (prevailing weather comb of factors) Bodies of water: lakes, oceans, rivers Seasons & positioning of the Earth Mountains
3-2 Energy Flow A. The Flow of Energy 1. All energy used by living organisms __________________________ 2. Use only ______ of the total energy _________________ originate from the sun. 1% Earth receives from the sun.
All energy used by living organisms: Sunlight energy Ecosystem originate from the sun Photosynthesis (in chloroplasts) Carbon dioxide Glucose Oxygen Water Cellular respiration (in mitochondria) for cellular work Heat energy
SUNPLANTSHerbivoresCarnivores 100%50% used immediatelyor by the plants; rest is Omnivores stored within roots as starch CONSUMERS PRODUCERS
4. Energy is _____________________ ______________________ 5. The raw materials can be recycled: _______________________ lost with each transfer and can’t be recycled! atoms/molecules
Sunlight Ecosystem The dynamics of any ecosystem depends on two processes: Heat 1. Cycling of nutrients 2. Flow of energy Consumers (such as animals) Heat Producers (plants and other photosynthetic organisms) Chemical energy (food) Figure 1.3
SUMMARY OF KEY CONCEPTS An Overview of Ecosystem Dynamics Heat Light Ecosystem Energy flow Producers Consumers Decomposers Chemical cycling (biotic abiotic) Visual Summary 19.1
a. autotrophic (self-feeding; producers) plants are photosynthetic b. heterotrophic (feeding on others; consumers) 1. Herbivores = ___________________ 2. Carnivores = ___________________ 3. Carnivores = ___________________ primary consumers secondary consumers tertiary consumers c. decomposers – or break down organic material into the same abiotic materials that we started with. Yes, nature is the champion recycler! mainly microscopic fungi and bacteria that metabolize
Derive their energy from the dead material left by all trophic levels • Are often left off of most food chain diagrams Detritivores, or decomposers Figure 19.22
Introductory Questions #7 • What does an ecological pyramid show us? Name the three types of pyramids discussed on pgs. 72 & 73. • Which pyramid shows us the amount of potential food available for each trophic level in an ecosystem? • Energy is a one-way flow system while matter is _________. (see pg. 74) • Name the FOUR geochemical cycles discussed in Sect. 3.3 (pgs. 75-79). Name the cycle that involve: -Evaporation & transpiration _______ -Many bacteria & fungi _______ -Photosynthesis & respiration _______ -Important for organisms making DNA and RNA _______ -Forms nitrates (NO3-), nitrites(NO2-), ammonia (NH3), and N2 gas. ____.
Energy flows through an ecosystem in one direction, beginning with solar energy. This stored energy then passes through a food chain, a series of organisms that successively eat one another. The trophic level, or feeding level, of an organism is the number of food chain links between it and the ecosystem’s energy source.
C. Feeding Relationships 1.Food chain: follow the progression of energy flow from one organism to another or “who eats whom.” a. shorter food chains are found in harsh climates like the desert and tundra . b.Desert or tundra areas are less stable and more easily destroyed than those found in more moderate climatic influences e.g. tropical rain forests.
2.Food webs: food chains interconnect, forming complex food webs. a.webs form when one species eats or is eaten by several other species and when one species functions at more than one trophic level. b.Example: a person eating a tuna sandwich is both a primary consumer (a herbivore, eating bread) and a tertiary consumer (a carnivore eating another carnivore, the tuna).
Autotrophs Heterotrophs Trophic Levels and Food Chains Producer Carnivore (secondary consumer) Herbivore (primary consumer) Light Energy and chemicals Detritus Detritivore (decomposer) Organic and inorganic compounds Visual Summary 19.2
LEVEL NAME KIND OF ORGANISM TYPES OF FEEDING ENERGY SOURCE 1st trophic Primary producer Plants Autotroph Sun 2nd trophic Primary consumer Herbivores Heterotroph Plants 3rd trophic Secondary consumer Carnivore Heterotroph Herbivores 4th trophic Tertiary consumer Top carnivore Heterotroph Carnivores 5th trophic decomposer Detritivore Heterotroph All other organisms
Trophic Levels and Food Chains Quaternary consumers A food chain: Carnivore • Is the sequence of food transfer from trophic level to trophic level • May have many levels Carnivore Tertiary consumers Carnivore Carnivore Secondary consumers Carnivore Carnivore Primary consumers Zooplankton Herbivore Producers Plant Phytoplankton Figure 19.21 A marine food chain A terrestrial food chain
D. Ecological Pyramids 1.shows energy relationships among each trophic level 2.way of visually demonstrating a food chain 3.shape of the pyramid shows that the transfer of energy from one level to the next is not that efficient 4.Note that 90% of all the grasses and cereal grains fed cattle are used and lost by a cow as body heat, wastes and to provide the energy for a cow to survive. Only 10% is actually used in manufacturing muscle tissue (beef steaks).
6. Relative to the human diet, it is more efficient to eat plant materials than to eat the cows that ate the plant material. Some 90% of all the grain produced in this country is fed to livestock.
5. The base level of a biotic pyramid contains plant life; the greatest number of individuals; the greatest amount of potential food energy; and, the greatest amount of biomass (weight). Approximately 90% loss of energy at each trophic level Energy
Biomagnification (DDT,PCB,Metals) Food Chain Efficiency Cod, Tuna, Marine Mammals 5 PPM 0.20 BT 10% .5 PPM 2 BT Squid, Sardines, Anchovies, Herring 10% Zooplankton, Copepods, Krill 20 BT .04 PPM 10% 200 BT . .003 PPM Phytoplankton, Diatoms, Cyanobacteria .00003 PPM
Biological Magnification Trophic process in which retained substances become more concentrated at higher levels See pg. 1202 another example PCB (polychlorinated biphenyls) in the Great lakes.
What Happens as Energy Moves Through a Food Chain? Energy is lost mainly as heat in each transformation
What Happens as Energy Moves Through a Food Chain? Organisms are not 100% efficient Only 10% of the energy at one level makes it to the next level (90%lost)
Always have a pyramid shape energy is always lost as you go up Shape = the 10% rule More energy is maintained if there are fewer levels why we should eat lower off the food chain Pyramid of Energy
Eating producers instead of consumers requires less photosynthetic productivity (feeding the cows) and reduces the impact on the environment Human meat-eaters Secondary consumers Primary consumers Human vegetarians Cattle Corn Corn Producers (a) (b) Figure 19.27
Bioamplification • Transfer of harmful chemicals throughout the ecosystem • DDT and other pesticides • PCB’s & other endocrine disrupter
3-3 Cycles of Matter A. Biogeochemical Cycles: 1. Water cycle a. driven by (2) processes: evaporation and condensation b. water enters the atmosphere by transpiration of plants as well as evaporation. c. condensation = forms H20 into rain clouds d. precipitation = release of H20 from clouds to surface