Chapter 3 The Biosphere.

Chapter 3 The Biosphere

3-1 I. Ecology A. scientific study of interactions among organisms and between organisms and their environment, or surroundings B. Ecological Levels of Organization 1. Organism = One individual One group of species in same place and time 2. Population = 3. Community = Two or more species (populations) that interact Communities interacting with abiotic factors 4. Ecosystem =

Group of “like” ecosystems
5. Biome = Group of “like” ecosystems pertains to area where living organisms occur (land, water, air) 6. Biosphere = a. extends from about 8 km (3.6 miles) up to as far as 11 km (5 miles) down Biosphere Biome Ecosystem Community Population Individual

C. Ecological Methods 1. Observation-using any one or all of the five senses 2. Experimenting- in a lab or in the field 3. Modeling = Using math formulas based on observation and experimentation example: Hardy-Weinberg Principle

3-2 I. Energy Flow A. Producers = (autotrophs) produce their own food
1. Photoautotrophs = use sunlight to make their own food 2. Chemoautotrophs – use inorganic chemicals to make their own food (heterotrophs-MANY types) rely on other organisms for their food B. Consumers = 1. Herbivores, Carnivores, Omnivores, Detritivores (feed on plant and animal remains), Decomposers (break down dead organic matter)

II. Feeding Relationships
One way flow of energy from producers to consumers A. Food Chain = Page 69 Small Fish Zooplankton Squid Shark Algae 1. Eventually end up with decomposers

B. Food Web = Shows more complex interactions 1. All possible feeding relationships 2. More realistic C. Trophic Level = Each step in a food chain/web 1. Producers are 1st, consumers 2nd, 3rd etc. Page 71

III. 3 Types of Ecological Pyramids
A. Energy Pyramid (Page 72) 1. Shows the relative amount of energy available at each trophic level 0.1% Third-level consumers 2. Only 10% is transferred to the next level because organisms fail to capture and eat all of the food available or used for metabolism 1% Second-level consumers 10% First-level consumers 100% Producers

B. Biomass Pyramid (page 72)
1. The total amount of living tissue within a given trophic level 2. expressed in terms of grams 50 grams of human tissue 500 grams of chicken 3. represents the amount of potential food available for each trophic level 5000 grams of grain

C. Pyramid of Numbers (Page 73)
1. shows the relative number of individual organisms at each trophic level 2. Decreases at each higher trophic level 3. Not true for forests because one tree can serve many other organisms; not a typical pyramid of #s

3-3 I. The 4 Major Cycles of Matter A. Biogeochemical Cycles
1. Matter is passed from one organism to another and from one part of the biosphere to another B. Water Cycle 1. Rain, run-off, seepage, root uptake, evaporation/transpiration, condensation (clouds), back to rain 2. Transpiration = special form of evaporation; water evaporates from plants leaves to atmosphere

The Water Cycle Page 75

C. Carbon Cycle 1. Carbon moves in biosphere by: photosynthesis, respiration, decomposition, volcanoes, coal/fossil fuels, mining 2. Carbon is a key ingredient of living tissue-we are carbon-based life forms

Carbon Cycle Page 77 CO2 in Atmosphere CO2 in Ocean Carbonate Rocks
Photosynthesis Volcanic activity feeding Respiration Erosion Human activity Respiration Decomposition CO2 in Ocean Uplift Carbon is found in several large reservoirs in the biosphere. In the atmosphere, it is found as carbon dioxide gas; in the oceans as dissolved carbon dioxide; on land in organisms, rocks, and soil; and underground as coal, petroleum, and calcium carbonate rock. Deposition Photosynthesis feeding Fossil fuel Deposition Carbonate Rocks Page 77

D. Nitrogen Cycle 1. All organisms require nitrogen to make proteins 2. Only bacteria can use Nitrogen gas as is  must be converted to another form for other organisms to use 3. Nitrogen Fixation = bacteria change N into useable form (ammonia) 4. Such bacteria live in the soil and on the roots of plants called legumes (ex. soybean) 5. Other soil bacteria convert nitrates into N gas in a process called denitrification: releases nitrogen into the atmosphere

Nitrogen Cycle Page 78 NH3 N2 in Atmosphere NO3 and NO2
Synthetic fertilizer manufacturer Atmospheric nitrogen fixation Denitrification Uptake by producers Reuse by consumers Uptake by producers Reuse by consumers The atmosphere is the main reservoir of nitrogen in the biosphere. Nitrogen also cycles through the soil and through the tissues of living organisms. Decomposition, excretion Decomposition, excretion Bacterial nitrogen fixation NO3 and NO2 NH3 Page 78

E. Phosphorus Cycle 1. Not common in atmosphere 2. Two Cycles: a. Short-term  plants get phosphorus from soil, animals eat plants and die, phosphorus is back in soil b. Long-term  rock exposed, phosphorus washed into sea by erosion, gets back into rock

Phosphorus Cycle Page 79 Short-term cycle Organic phosphate moves through the food web and to the rest of the ecosystem. Organisms Phosphorus in the biosphere cycles among the land, ocean sediments, and living organisms. Land Ocean Long-term cycle Sediments

a. Controlled by the amount of available nutrients
F. Nutrient Limitation 1. primary productivity of an ecosystem is the rate at which organic matter is created by producers a. Controlled by the amount of available nutrients 2. When a a single nutrient is scarce or cycles very slowly, this substance is called a limiting nutrient because it limits growth, development and reproduction of all organisms within the ecosystem. a. When an aquatic ecosystem receives a large input of a limiting nutrient— such as phosphorus runoff from heavily fertilized fields—the result is often an immediate increase in the amount of algae and other producers = Algal Bloom  disrupts the equilibrium of an ecosystem- decomposition causes all aquatic life to die.

3-1 The combined portions of the planet in which life exists, including land, water, and the atmosphere, form the A. biosphere. B. community. C. species. D. ecosystem.

3-1 A group of organisms that can breed and produce fertile offspring is known as a(an) A. ecosystem. B. species. C. biome. D. community.

3-1 Compared to a community, an ecosystem includes
A. the nonliving, physical environment as well as the community. B. only the physical environment of an area without the organisms. C. the entire biome but not the biosphere. D. only one of the populations within the community.

3-1 An ecological method that uses mathematical formulas based on data collected is A. observing. B. experimenting. C. modeling. D. hypothesizing.

3-1 An ecologist marks out an area in a specific ecosystem and proceeds to identify the number of insect species in the area. This is an example of ecological A. experimentation. B. observation. C. modeling. D. inference.

3–2 The main source of energy for life on Earth is
A. organic chemical compounds. B. inorganic chemical compounds. C. sunlight. D. producers.

3–2 Organisms that feed on plant and animal remains and other dead matter are A. detritivores. B. carnivores. C. herbivores. D. autotrophs.

3–2 How does a food web differ from a food chain?
A. A food web contains a single series of energy transfers. B. A food web links many food chains toget C. A food web has only one trophic level. D. A food web shows how energy passes from producer to consumer.

3–2 In a biomass pyramid, the base of the pyramid represents the mass of A. heterotrophs. B. primary consumers. C. producers. D. top level carnivores.

3–2 The amount of energy represented in each trophic level of consumers in an energy pyramid is about A. 10% of the level below it. B. 90% of the level below it. C. 10% more than the level below it. D. 90% more than the level below it.