CHAPTER 14CHAPTER 14

ECOSYSTEM ORGANIZATION AND ENERGY FLOWECOSYSTEM ORGANIZATION AND ENERGY FLOW

ECOLOGY AND ECOLOGY AND ENVIRONMENTENVIRONMENT

EcologyEcology – the branch of biology that – the branch of biology that studies the relationships between studies the relationships between organisms and the environmentorganisms and the environment

The The environmentenvironment is anything that is anything that affects an organism during its affects an organism during its lifetimelifetime

Organisms are affected by both Organisms are affected by both bioticbiotic (living) and (living) and abioticabiotic (nonliving) (nonliving) factors of the environmentfactors of the environment

ORGANIZATION OF ORGANIZATION OF ECOLOGICAL SYSTEMSECOLOGICAL SYSTEMS

Ecologists study ecological relationships Ecologists study ecological relationships at different levels of organization:at different levels of organization:

OrganismOrganism – smallest, independent living – smallest, independent living unitunit

Ex: one leopard frogEx: one leopard frog PopulationPopulation - members of the same species - members of the same species

living in a particular arealiving in a particular area Ex: leopard frogs in a pondEx: leopard frogs in a pond

CommunityCommunity - populations of different - populations of different species living in the same areaspecies living in the same area

Ex: pond community (frogs, fish, plants, etc.) Ex: pond community (frogs, fish, plants, etc.)

ECOLOGICAL SYSTEMSECOLOGICAL SYSTEMS An An ecosystemecosystem - all interacting - all interacting

organisms in an area and how they organisms in an area and how they interact with their abiotic surroundings.interact with their abiotic surroundings.

Living things can be organized into Living things can be organized into energy relationships.energy relationships.

ProducersProducers – trap sunlight, carry out – trap sunlight, carry out photosynthesisphotosynthesis

ConsumersConsumers – feed on producers – feed on producers Trophic levelsTrophic levels – describe how energy – describe how energy

flows through an ecosystemflows through an ecosystem Producers occupy the first trophic levelProducers occupy the first trophic level Arranged like a pyramidArranged like a pyramid

ECOLOGICAL SYSTEMSECOLOGICAL SYSTEMS

Consumers can be divided into:Consumers can be divided into: primary consumersprimary consumers secondary consumers secondary consumers

Primary consumers feed directly on plants Primary consumers feed directly on plants are known as are known as herbivoresherbivores (mouse) (mouse)

Second trophic levelSecond trophic level Secondary consumers feed on other Secondary consumers feed on other

animals and are called animals and are called carnivorescarnivores (snake)(snake)

Third trophic levelThird trophic level Animals that feed on carnivores are Animals that feed on carnivores are

fourth trophic level consumers (hawk)fourth trophic level consumers (hawk)

TROPHIC LEVELSTROPHIC LEVELS

ECOLOGICAL SYSTEMSECOLOGICAL SYSTEMS Omnivores – feed on both plants and Omnivores – feed on both plants and

animalsanimals Can occupy different trophic levelsCan occupy different trophic levels

Decomposers – feed on dead Decomposers – feed on dead organisms as their source of energyorganisms as their source of energy

Includes bacteria and fungiIncludes bacteria and fungi Convert organic matter into inorganic Convert organic matter into inorganic

matter that can be used by producersmatter that can be used by producers

COMMUNITY COMMUNITY INTERACTIONSINTERACTIONS

All consumers depend on All consumers depend on producers for their energy (directly producers for their energy (directly or indirectly).or indirectly).

One way to study interactions One way to study interactions among communities involves among communities involves analysis of the various analysis of the various food chainsfood chains..

Show linear feeding patternsShow linear feeding patterns Organisms can be involved in Organisms can be involved in

several food chains at the same several food chains at the same time forming a time forming a food webfood web. .

Show complex feeding patternsShow complex feeding patterns

COMMUNITY COMMUNITY INTERACTIONSINTERACTIONS

Changes in the population size of Changes in the population size of one species can influence one species can influence population sizes of other species.population sizes of other species.

Insecticide use may decrease the Insecticide use may decrease the population size of organisms that feed population size of organisms that feed on insects. on insects.

Population sizes may change due Population sizes may change due both biotic and abiotic factorsboth biotic and abiotic factors

WORLD BIOMESWORLD BIOMES

TEMPERATE DECIDUOUSTEMPERATE DECIDUOUS Found in areas with Found in areas with

moderate rainfall (75-moderate rainfall (75-130 cm per year)130 cm per year)

Long summers (130-Long summers (130-160 days)160 days)

Colonized by many Colonized by many large deciduous trees large deciduous trees

Typical animals include:Typical animals include: leaf eating animals, leaf eating animals,

insectsinsects Birds, skunks, deerBirds, skunks, deer mosquitoes , etc. mosquitoes , etc.

GRASSLANDGRASSLAND Also known as a prairieAlso known as a prairie Average rainfall amount Average rainfall amount

is 30-85 cm per yearis 30-85 cm per year Not adequate to support Not adequate to support

the growth of treesthe growth of trees Mostly grasses and Mostly grasses and

wildflowerswildflowers Good for agricultural crops Good for agricultural crops

(corn, wheat)(corn, wheat) Experience long periods Experience long periods

of droughtof drought Common animals Common animals

include:include: Grazing mammalsGrazing mammals Small insectsSmall insects RodentsRodents CarnivoresCarnivores

SAVANNASAVANNA Similar to a prairieSimilar to a prairie Receive about 100 cm Receive about 100 cm

of rainfall per yearof rainfall per year Home to many grazing Home to many grazing

animalsanimals Have a dry season and Have a dry season and

a rainy seasona rainy season During the rainy During the rainy

season, trees produce season, trees produce leaves and the grass leaves and the grass grows rapidlygrows rapidly

In the African In the African savanna, migration is savanna, migration is typical.typical.

DESERTDESERT Very dry areas found Very dry areas found

all over the world all over the world Receive less than 25 Receive less than 25

cm of rainfall per yearcm of rainfall per year Plants are adapted for Plants are adapted for

conserving waterconserving water Scattered, thorny Scattered, thorny

plantsplants Many animals can live Many animals can live

here, most are here, most are nocturnalnocturnal

BOREAL CONIFEROUS BOREAL CONIFEROUS FORESTFOREST

Include the evergreen Include the evergreen areasareas

Annual rainfall of 40-Annual rainfall of 40-100 cm per year100 cm per year

Growing season is less Growing season is less than 102 daysthan 102 days

Trees must withstand Trees must withstand long cold winterslong cold winters

Animals include mice, Animals include mice, bears, wolves, moose, bears, wolves, moose, and fliesand flies

TUNDRATUNDRA Long, severe winters and short summers of less Long, severe winters and short summers of less

than 100 daysthan 100 days Little rainfall (10-25 cm per year)Little rainfall (10-25 cm per year) Deep layers of soil are permanently frozen Deep layers of soil are permanently frozen

(permafrost)(permafrost) Supports very few forms of animals and plants.Supports very few forms of animals and plants. No trees can live in this biome.No trees can live in this biome.

TEMPERATE TEMPERATE RAINFORESTRAINFOREST

Receive about 200 cm of rain per Receive about 200 cm of rain per yearyear

Found in fertile and mild Found in fertile and mild temperatures with lush plant temperatures with lush plant growth.growth.

Undisturbed areas have 800-year-Undisturbed areas have 800-year-old trees nearly 100 meters tallold trees nearly 100 meters tall

Many are covered with mosses Many are covered with mosses and fernsand ferns

Over 90% of the original Over 90% of the original temperate rainforests have temperate rainforests have already been logged.already been logged.

Found near coastal areas of Found near coastal areas of Pacific northwestPacific northwest

Northern California, Northern California, Oregon, Washington, Oregon, Washington, Canada, AlaskaCanada, Alaska

TROPICAL RAINFORESTTROPICAL RAINFOREST Found primarily in the Found primarily in the

equatorial regions.equatorial regions. Considered the richest Considered the richest

biomebiome Warm temperatures Warm temperatures

year round, and rain year round, and rain falls almost daily (200-falls almost daily (200-1000 cm a year)1000 cm a year)

Thousands of species of Thousands of species of plants in very small plants in very small areasareas

Many species of animals Many species of animals

SUCCESSIONSUCCESSION Communities are relatively stable Communities are relatively stable

when left undisturbedwhen left undisturbed Known as climax communities Known as climax communities

Succession is the process of changing Succession is the process of changing from one type of community to another from one type of community to another

Two types:Two types: Primary succession - occurs in areas where Primary succession - occurs in areas where

plants and animals didn’t exist before plants and animals didn’t exist before (volcanic areas)(volcanic areas)

Secondary succession – occurs when a Secondary succession – occurs when a community is disturbed by natural or human community is disturbed by natural or human action, and it returns to a previous stage in action, and it returns to a previous stage in the succession (forest fires, clear cutting)the succession (forest fires, clear cutting)

PRIMARY SUCCESSION

SECONDARY SUCCESSION

CHAPTER 14CHAPTER 14

ECOSYSTEM ORGANIZATION AND ENERGY FLOWECOSYSTEM ORGANIZATION AND ENERGY FLOW

KINDS OF INTERACTIONSKINDS OF INTERACTIONS

PredationPredation – a predator captures prey, – a predator captures prey, kills it, and eats it.kills it, and eats it.

Elimates poorly adapted individualsElimates poorly adapted individuals ParasitismParasitism – the host is harmed and – the host is harmed and

the parasite benefitsthe parasite benefits Parasites can live inside or outside the Parasites can live inside or outside the

host. host. Mistletoe, tapeworms, fleasMistletoe, tapeworms, fleas

VectorsVectors are organisms that can spread are organisms that can spread parasites.parasites.

Mosquitoes, ticksMosquitoes, ticks

KINDS OF KINDS OF INTERACTIONS INTERACTIONS

CommensalismCommensalism – one organism benefits and the – one organism benefits and the other is not affected. other is not affected.

Remoras and sharksRemoras and sharks Tree mossesTree mosses

MutualismMutualism – both organisms benefit from one – both organisms benefit from one anotheranother

E.coliE.coli and humans and humans Bees and flowering plantsBees and flowering plants

CompetitionCompetition – an interaction between organisms in – an interaction between organisms in which both organisms are harmed to some extent.which both organisms are harmed to some extent.

Weeds and garden plantsWeeds and garden plants Occupying different niches helps reduce Occupying different niches helps reduce

competitioncompetition

PRIMARY SUCCESSION

SECONDARY SUCCESSION