chapter 37 communities and ecosystems - north …€™s use of the biotic and abiotic resources in...

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© 2012 Pearson Education, Inc. Lecture by Edward J. Zalisko

PowerPoint Lectures for

Campbell Biology: Concepts & Connections, Seventh EditionReece, Taylor, Simon, and Dickey

Chapter 37 Communities and Ecosystems

Introduction

Natural ecosystems are valuable because they

– provide ______________________,

– support outdoor recreation, and

– provide natural services including

– _________________against hurricane damage,

– recycling ______________________,

– preventing erosion, and

– _______________________crops.

© 2012 Pearson Education, Inc.

Figure 37.0_2

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COMMUNITY STRUCTURE AND DYNAMICS


37.1 A community includes all the organisms inhabiting a particular area

Community ecology is concerned with factors that

– influence species _________________and distribution of communities and

– affect community ____________________.


37.1 A community includes all the organisms inhabiting a particular area

A biological ___________________is

– an assemblage of all the ______________of organisms living close enough together for potential interaction and

– described by its species composition.

The boundaries of a community vary with the research question to be _________. For example, the boundaries of a community could be defined as

– a _____________or

– the intestinal ______________of a pond organism.


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___________________interactions

– are relationships with individuals of __________species in the community,

– greatly __________population structure and dynamics, and

– can be categorized according to their effect on the interacting populations.

37.2 Interspecific interactions are fundamental to community structure


_____________competition occurs when populations of two different species compete for the same limited resource.

– In ___________, both populations benefit.

– In ___________, one species (the predator) kills and eats another (the prey).

– In _____________, an animal consumes plant parts or algae.

– In ____________, the host plants or animals are victimized by parasites or pathogens.

37.2 Interspecific interactions are fundamental to community structure


Table 37.2

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37.3 Competition may occur when a shared resource is limited

An __________________is the sum of an organism’s use of the biotic and abiotic resources in its environment.

Interspecific competition occurs when the ______of two populations overlap.

Competition lowers the _____________of competing populations because the resources used by one population are not available to the other population.


Figure 37.3A

37.4 Mutualism benefits both partners

Reef-building corals and _____________ dinoflagellates illustrate the win/win nature of mutualism. Photosynthetic dinoflagellates

– gain shelter in the cells of each coral _______,

– produce sugars used by the polyps, and

– provide at least half of the ________used by the coral animals.


Video: Clownfish and Anemone

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Figure 37.4

37.5 EVOLUTION CONNECTION: Predation leads to diverse adaptations in prey species

Predation benefits the predator but kills the prey.

Prey ________using protective strategies that include

– _____________,

– mechanical ___________, and

– chemical defenses.


Video: Seahorse Camouflage

Figure 37.5A

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Herbivores and plants undergo ____________,

– a series of ___________evolutionary adaptations in two species,

– in which change in one species acts as a new ___________ force on another.

37.6 EVOLUTION CONNECTION: Herbivory leads to diverse adaptations in plants


37.6 EVOLUTION CONNECTION: Herbivory leads to diverse adaptations in plants

A plant whose body parts have been _________by an animal must expend energy to replace the loss.

– Thus, numerous defenses against __________have evolved in plants.

– Plant defenses against herbivores include

– ___________and thorns and

– _______________toxins.


Figure 37.6

Eggs

Sugardeposits

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37.7 Parasites and pathogens can affect community composition

A ________lives on or in a host from which it obtains nourishment.

– __________parasites include nematodes and tapeworms.

– External parasites include mosquitoes, ticks, and aphids.

__________are disease-causing microscopic parasites that include

– _____________,

– viruses,

– _______________, or

– protists.© 2012 Pearson Education, Inc.

Figure 37.7

_____________ pathogens can have rapid and dramatic impacts.

– The American chestnut was devastated by the chestnut blight ________________.

– A fungus-like pathogen is currently causing sudden oak death on the West Coast.

Non-native ___________can cause a decline of the ecosystem.

37.7 Parasites and pathogens can affect community composition


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37.8 Trophic structure is a key factor in community dynamics

The ___________of a community is a pattern of feeding relationships consisting of several different levels.

– The sequence of food transfer up the trophic levels is known as a ____________.

– The transfer of food moves chemical __________and energy from producers up through the trophic levels in a community.


__________________

– are _________________and

– support all other trophic levels.

Consumers are heterotrophs.

– Herbivores are __________ consumers.

– ____________consumers typically eat herbivores.

– Tertiary consumers typically eat secondary consumers.

– ____________consumers typically eat tertiary consumers.



____________derive their energy from detritus, the dead material produced at all the trophic levels.

__________________

– are mainly ______________and fungi and

– secrete enzymes that digest molecules in organic materials and convert them into inorganic forms, in the process called decomposition.



Video: Shark Eating a Seal

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Figure 37.8_s5Trophic level

Plant

A terrestrial food chain An aquatic food chain

ProducersPhytoplankton

GrasshopperPrimary

consumers Zooplankton

MouseSecondaryconsumers Herring

TunaSnake

Tertiaryconsumers

Killer whaleHawk

Quaternaryconsumers

37.9 Food chains interconnect, forming food webs

A _____________is a network of interconnecting food chains.

Notice that

– ________________may eat more than one type of producer and

– several species of consumers may feed on the same species of producer.


Figure 37.9Quaternary,tertiary,and secondaryconsumers

secondaryconsumers

Tertiaryand

Secondaryandprimaryconsumers

Primaryconsumers

Producers(plants)

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Figure 37.9_1

Primaryconsumers

Producers(plants)

Figure 37.9_2

Quaternary,tertiary,and secondaryconsumers

secondaryconsumers

Tertiaryand

Secondaryandprimaryconsumers

Primaryconsumers

37.10 Species diversity includes relative abundance and species richness

_______________is defined by two components:

1. Species richness, the _________of species in a community, and

2. Relative ___________, the proportional representation of a species in a community.


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37.10 Species diversity includes relative abundance and species richness

__________species diversity in a community affects the species diversity of animals.

Species diversity has consequences for __________.

Low species diversity is characteristic of most modern ___________________ecosystems.


Figure 37.10A

Woodlot A Woodlot B

Table 37.10

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37.11 Keystone species have a disproportionate impact on diversity

A ________________species

– is a species whose impact on its community is larger than its biomass or abundance indicates and

– occupies a _____________that holds the rest of its community in place.

Examples of keystone species in marine ecosystems include

– Pisaster ______________and

– long-spined sea urchins.


Figure 37.11A

Keystone

Keystoneabsent

Figure 37.11B

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37.12 Disturbance is a prominent feature of most communities

____________________

– are events that ____________biological communities and

– include ________________, fires, floods, droughts, overgrazing, or ______________activity.

– The types, frequency, and severity of disturbances vary from community to community.


Communities change ______________following a severe disturbance that

– strips away ____________and

– removes significant amounts of soil.

_________________________results from colonization by a variety of species, which are replaced by a succession of other species.



_____________ succession begins in a virtually lifeless area with no soil.

______________succession occurs when a disturbance destroys an existing community but leaves the soil intact.



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Figure 37.12A

Figure 37.12B

Annualplants

Perennialplants and

grasses

Shrubs Softwood treessuch as pines

Hardwoodtrees

Time

37.13 CONNECTION: Invasive species can devastate communities

__________________species

– are organisms that have been introduced into _____________ habitats by human actions and

– have established themselves at the expense of native communities.

– The absence of natural ______________often allows rapid population growth of invasive species.


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37.13 CONNECTION: Invasive species can devastate communities

Examples of invasive species include the deliberate introduction of

– _______________into Australia and

– _________________into Australia.


Figure 37.13B

ECOSYSTEM STRUCTURE AND DYNAMICS


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37.14 Ecosystem ecology emphasizes energy flow and chemical cycling

An _______________consists of

– all the organisms in a community and

– the abiotic environment with which the organisms interact.

In an ecosystem,

– ______________moves through the components of an ecosystem and

– ___________________is the transfer of materials withinthe ecosystem.


A terrarium

– represents the components of an ecosystem and

– illustrates the fundamentals of __________flow.

37.14 Ecosystem ecology emphasizes energy flow and chemical cycling


Figure 37.14

Energy flow

Chemicalenergy

Lightenergy

Bacteria,protists,and fungi

Chemicalelements

Heatenergy

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37.15 Primary production sets the energy budget for ecosystems

_______________production

– is carried out by ______________,

– is the amount of solar energy converted to chemical energy by an ecosystem’s producers for a given area and during a given time period, and

– produces _________________, the amount of living organic material in an ecosystem.

Different ecosystems vary in their

– ______________production and

– contribution to the total production of the biosphere.


Figure 37.15

Open ocean

Estuary

Algal beds and coral reefs

Desert and semidesert scrub

Tundra

Temperate grassland

Cultivated land

Boreal forest (taiga)

Savanna

Temperate deciduous forest

Tropical rain forest

0 500 1,000 1,500 2,000 2,500

Average net primary productivity (g/m2/yr)

37.16 Energy supply limits the length of food chains

A caterpillar represents a __________consumer.

Of the organic compounds a caterpillar ingests, about

– __________% is eliminated in feces,

– __________% is used in cellular respiration, and

– ____________% is used for growth.


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Figure 37.16A

Plant materialeaten by caterpillar

100 kilocalories (kcal)

50 kcal35 kcal

15 kcalFeces

Cellularrespiration

Growth

37.16 Energy supply limits the length of food chains

A _____________of production shows the flow of energy

– from producers to primary consumers and

– to higher trophic levels.

Only about __________of the energy stored at each trophic level is available to the next level.


Figure 37.16B

Tertiaryconsumers

Secondaryconsumers

Primaryconsumers

Producers

10 kcal

100 kcal

1,000 kcal

10,000 kcal

1,000,000 kcal of sunlight

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37.17 CONNECTION: A pyramid of production explains the ecological cost of meat

When humans eat

– ___________or fruit, we are primary consumers,

– _________or other meat from herbivores, we are secondary consumers, and

– fish like trout or salmon, we are ____________or quaternary consumers.


37.17 CONNECTION: A pyramid of production explains the ecological cost of meat

Only about _______% of the chemical energy available in a trophic level is passed to the next higher trophic level.

Therefore, the human population has about ten times more energy available to it when people eat ______________instead of the meat of herbivores.

Eating meat of any kind is expensive

– __________________and

– environmentally.


Figure 37.17

Trophic level

Vegetarians

Corn Corn

Cattle

Meat-eaters

Primaryconsumers

Secondaryconsumers

Producers

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37.18 Chemicals are cycled between organic matter and abiotic reservoirs

Ecosystems are supplied with a continual influx of energy from the

– ________________and

– Earth’s interior.

Except for ______________, there are no extraterrestrial sources of chemical elements.

Thus, life also depends on the ___________of chemicals.


_______________cycles include

– _____________components,

– abiotic components, and

– ____________reservoirs, where a chemical accumulates or is stockpiled outside of living organisms.

Biogeochemical cycles can be

– local or

– global.

37.18 Chemicals are cycled between organic matter and abiotic reservoirs


Figure 37.18

Consumers

Producers

Decomposers

Nutrientsavailableto producers

Abioticreservoirs

Geologic processes

4

1

2

3

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37.19 The carbon cycle depends on photosynthesis and respiration

_______________is

– the major ingredient of all organic molecules and

– found in

– the atmosphere,

– ____________fuels, and

– dissolved in carbon compounds in the ocean.

The return of CO2 to the atmosphere by _________ closely balances its removal by photosynthesis.

The carbon cycle is affected by burning wood and fossil fuels.


Figure 37.19

CO2 in atmosphere

Cellular respiration

Burning

Woodand

fossilfuels

Higher-levelconsumers

5

3

2

4

Decomposition

Decomposers(soil microbes) Detritus

Wastes; death

Primaryconsumers

Plant litter;death

Plants, algae,cyanobacteria

Photosynthesis1

37.20 The phosphorus cycle depends on the weathering of rock

Organisms require _____________for

– ___________acids,

– phospholipids, and

– ATP.


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37.20 The phosphorus cycle depends on the weathering of rock

The _____________cycle does not have an atmospheric component.

_______are the only source of phosphorus for terrestrial ecosystems.

Plants absorb phosphate ions in the soil and build them into organic compounds.

Phosphates are returned to the soil by ____________.

Phosphate levels in aquatic ecosystems are typically low enough to be a limiting factor.


Figure 37.20

Upliftingof rock Weathering

of rock

Phosphatesin rock

Phosphatesin solution

Runoff

Assimilation

Rock

Decomposition

Phosphatesin soil

(inorganic)

Precipitated(solid) phosphates

Decomposersin soil

Detritus

AnimalsPlants

3

1

2

4

5

6

37.21 The nitrogen cycle depends on bacteria

________________is

– an ingredient of ______________and nucleic acids,

– essential to the structure and functioning of all organisms, and

– a crucial and often limiting plant nutrient.

Nitrogen has two abiotic reservoirs:

1. the atmosphere, of which about 80% is nitrogen gas, and

2. ______________.


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37.21 The nitrogen cycle depends on bacteria

______________fixation

– converts N2 to compounds of nitrogen that can be used by plants and

– is carried out by some _______________.


Figure 37.21

Nitrogen (N2) in atmosphere

Plant Animal

Nitrogen-fixingbacteria in

root modules

Free-livingnitrogen-fixing

bacteria

Detritus

Decomposers

Ammonium (NH4)

in soil

Nitrifyingbacteria

Denitrifiers

Assimilationby plants

Nitratesin soil(NO3

)

8

6

5

3

4 7

2

1

37.22 CONNECTION: A rapid inflow of nutrients degrades aquatic ecosystems

In ______________ecosystems, primary production is limited by low nutrient levels of

– phosphorus and

– nitrogen.

Over time, standing water ecosystems

– gradually ____________nutrients from the decomposition of organic matter and fresh influx from the land, and

– primary production increases in a process known as eutrophication.


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________________of lakes, rivers, and coastal waters

– depletes oxygen levels and

– decreases species diversity.

In many areas, phosphate pollution leading to eutrophication comes from

– agricultural fertilizers,

– __________________,

– sewage treatment facilities, and

– runoff of animal waste from feedlots © 2012 Pearson Education, Inc.


____________of aquatic systems may also result from increased levels of nitrogen from

– feedlots and

– applications of large amounts of ______________.


Video: Cyanobacteria (Oscillatoria)

Figure 37.22A

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Figure 37.22B

Winter Summer

37.23 CONNECTION: Ecosystem services are essential to human well-being

Although agricultural and other managed ecosystems are necessary to supply our needs, we also depend on services provided by natural ecosystems.

Healthy ecosystems

– supply ___________water and some foods,

– recycle _______________,

– decompose wastes, and

– regulate ______________and air quality.


37.23 CONNECTION: Ecosystem services are essential to human well-being

Enormous increases in ____________production have come at the expense of

– _____________ecosystems and

– the services they provide.

Human activities also ____________many forest ecosystems and the services they provide.


chapter 37 communities and ecosystems - north …€™s use of the biotic and abiotic resources in...

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