Módulos de trabajo para Seminarios del Tema 1 Introducción ... · 04/04/2020 · Biocenosis (community) Biotope Biotic factors Abiotic factors Unit 12 Unit 12 An ecosystem refers

ESO2

ECOSYSTEMS

Unit 12

What is an ecosystem?

An ecosystem

consist of:

Biocenosis

(community)

Biotope

Biotic factors

Abiotic factors

Unit 12

Unit 12

An ecosystem refers to the organisms

which live in an area, the relationships

between them and their physical

environment. Thus, a forest is an

ecosystem, but a lagoon or a puddle of

water in that forest, are themselves

ecosystems too. A city is also an

ecosystem: a man-made ecosystem.

What is an ecosystem? Unit 12

Unit 12

The set of living species in it, that is, the biocenosis.

For instance, in a forest there could be pines, oaks, mice,

doves, butterflies, kites, ants…

The set of physical and chemical conditions, that is, the

biotope. In a forest: the average temperature in the

coldest month, the average temperature in the hottest

month, the rainfall rate, the kind of salts that exist in the

soil…

The relationships between the living species: the

pines holding the nests that doves make, the kites eating

the mice, the mushrooms feeding on the fallen leaves…

The relationships between the physical-chemical

conditions: how temperatures alter the soil's humidity

through evaporation, how wind wears away soil

particles…

What is an ecosystem? Unit 12

Unit 12

The relationships between the physical-chemical

conditions and the living species: the way in which the

animal activity is affected by the day-night cycle, the

way in which temperature affects the loss of water

vapour by plants through evapotranspiration, the way

plants retain the soil particles with their roots and

prevent them from being worn away by the wind, the

way in which the decomposition of fallen leaves or

dead animals adds new salts and minerals to the soil…

Just remember! Unit 12

Unit 12

• Species

• Population

• Community

• Ecosystem

How do living things obtain

food? Unit 12

Unit 12

• The way living things

obtain food

determines their

trophic level (their

place in the food

chain)

• An ecosystem has

three levels:

producers,

consumers and

decomposers

ESSENTIAL NATURAL SCIENCE 2

Unit 5 HOME CONTENTS RESOURCES

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Trophic levels

Producers Consumers Decomposers

Primary

Secondary

Tertiary

fungi

bacteria

How do living things obtain food?



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Producer

Primary consumer

Secondary consumer

Tertiary consumer

Tertiary consumer

A food chain

Unit 12

Unit 12

• There are

aquatic

food chain

and

terrestrial

food chain

How do living things obtain

food? Unit 12

Unit 12

• A set of

interacting

food chains

is

represented

by a food

web



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A food web

Ecological niches versus

habitat Unit 12

Unit 12



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Ecological niche

herbivores

insectivores

They

occupy

different

ecological

niches.

They share

the same

habitat.

They occupy

different

ecological niches.

This is the function a particular species has in an ecosystem.



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Habitats

A habitat is the physical place where a species lives.


habitat Unit 12

Unit 12

• Bucky’s niche or its

profession (our beaver

is a builder)


habitat Unit 11

Unit 12

• A barn owl ‘s habitat can be

the same as a squirrel’s

habitat but their niches are

quite different otherwise

they will compete


habitat Unit 12

Unit 12

Lizards inhabit a

broad range of

habitats, including

deserts, grasslands,

chaparral, rock

outcrops, deciduous

forest and rainforest.

Australia's largest lizard, the perentie Varanus

giganteus (2 meters long).


habitat Unit 12

Unit 12

• Giraffes and

zebras live in the

same habitat,

the savannah.

Giraffes feed on

leaves at the

tops of the trees,

but zebras feed

on leaves at

ground level

(different

ecological niche)

Abiotic factors Unit 12

Unit 12

• Temperature (TE)

• Light (AE)

• Humidity (TE)

• Chemical

composition of the

soil

• Water salinity (AE)

• Pressure (AE)


Unit 12


Unit 12



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Biotic relations

Gregarious

Familial

Colonial

Social

INTRASPECIFIC

RELATIONS

Mutualism

Commensalism

Depredation

Inquilinism

Parasitism

INTERSPECIFIC RELATIONS

Biotic factors Unit 12

Unit 12

• Intraspecific relationships or interaction

• Interspecific relationships or interaction

Intraspecific relations (same species):

Gregarious (migrating birds, herd instinct in gnus,

a herd of buffalo)

Colonial (a coral reef)

Social or eusocial colonies (ants, termites, bees)

Familial (monogamous, polygamous)


Unit 12


Social or eusocial colonies (ants, termites,

bees)

• Individuals are organised in

a hierarchy (anatomic and

physiological differences)

• Bees on a honeycomb (inside a beehive)


Unit 12


colonies (corals)

• Coral colonies • Coral Greet Barrier Reef


Unit 12


Gregarious: a herd of buffalo, a herd of gnus,

migrating birds)

• A herd of gnus • A flock of seagulls


Unit 12

• Interspecific relationships or interaction:

Mutualism (++) bees pollinate flowers, anemona and

clownfish

Symbiosis (++) lichen (an alga and a fungus)

Commensalism (+0) beetles feed on mammal

excrement, Shark and remora fish or suckerfish

Competition (- -)

Inquilinism (+0) hermit crabs live in empty shells

Parasitism (+-) cochineals on a cactus

Depredation or Predation (+-) cheetahs eat gazelles,

chameleon and grasshopper


Unit 12

• Interspecific relations

Clownfish and sea

anemone

Mutualism Symbiosis (lichens)

Competition (vultures and hyena

both are carrion-eaters)

Predation (bears

carnivorous


Unit 12

Commensalism (+ 0)

(beetles feeding on

mammal excrement)

Suckerfish feeding on sharks’ leftover

Interspecific relations

Black rhino and oxpeckers

Inquilinism (hermit crab)


Unit 12

• Commensalism (+ 0)

(Crocodile and birds)

Interspecific relations

Parasitism (+-) cochineals on a cactus

(carmine and lipstick)


Unit 12

Ladybirds eat aphids (+ -)

Predation

Ants and aphids (+ +)

Ants feed on the honeydew

excreted by the aphids, and in

exchange, they protect the

aphids (Mutualism)

Competition (red deer)

“intraspecific”


Unit 12



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Adaptations to terrestrial ecosystems

Abiotic

factor Adaptations of living things

humidity

light

temperature

large leaves

height

nocturnal activity

spines

stomata

scales

substances

exoskeleton

homeotherms

poikilotherms



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Adaptations to aquatic ecosystems

Abiotic

factor Adaptations of living things

light

water

movement

pressure

bioluminescense pigments

shape

round shape

ways fish

swim

fixed to surfaces

shelter

flat body shape hydrodynamic shape

swim bladder

Adaptation to the

environment Unit 12

Unit 12

• Homeotherms (warm-blooded animals)

• Poikilotherms (cold-blooded animals) some of them hibernate

or take a sunbath

Obligate hivernators rodents

(squirrels, hamsters), bears

Tortoise and hibernation

What are trophic pyramids? Unit 12

Unit 12

• A trophic pyramid is a graphic

representation of a particular

characteristic at each trophic

level. There are three types of

trophic pyramid:

Number pyramid

Biomass pyramid

Energy pyramid



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Trophic pyramids

Number pyramid

number of individuals

at each trophic level

unit of area or volume

producers

primary

consumers

secondary

consumers

tertiary

consumers

tertiary

consumers

producers

primary

consumers

secondary

consumers

Biomass pyramid

amount of organic matter


Energy pyramid

energy stored at each trophic

level at a certain time

producers

primary

consumers

tertiary

consumers

solar energy heat

heat

heat

heat secondary

consumers


Unit 12

Number pyramid


Unit 12

Number pyramid


Unit 12

Biomass pyramid this

represent the biomass or

amount of organic matter.

Biomass is measured in

grams or kilograms per



Unit 12

Energy pyramid this

represent the energy

stored at each trophic

level at a certain time

(kcal /m2 year)

How are matter and energy

transmitted? Unit 12

Unit 12

A closed cycle of matter

A one-way flow of energy



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Flow of energy

Producers Primary

consumers

Secondary

consumers

Tertiary

consumers

Decomposers

solar

energy Released energy (heat)

A one-way flow of energy

How are matter and energy

transmitted? Unit 12

Unit 12



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Cycle of matter

Producers Primary

consumers Secondary

consumers

Tertiary

consumers

Inorganic matter

Decomposers

A closed cycle of matter



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Self-regulation of population

SEE PREDATOR-PREY

SYSTEM

Number of individuals

Carrying capacity

(equilibrium population size) (K)

1

2

3

4

Time

Settlement period 1

Exponential growth 2

K limits growth and the

population stabilises. 3


fluctuates around K. 4



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Self-regulation of population

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rabbit lynx

YEAR


1845 1855 1865 1875 1885 1895 1905 1915 1925 1935

20

40

60

80

100

120

140

160

Biomes Unit 12

Unit 12

Biomes Unit 12

Unit 12



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Cultivated land

ferns

tree

vole

rabbit

wheat

field

fox

field

mouse

bird of prey

weeds



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High mountain ecosystems

falcon

chamois

lizard

pines



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Types of aquatic ecosystems

Lentic ecosystems:

pools, ponds and lakes

Marine

ecosystems

Neritic zone open ocean According

to distance

According to depth neritic zone

pelagic zone

abyssal plain

200 m

2 000 m

Lotic ecosystems:

streams and rivers

Freshwater

ecosystems



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Marine animals

Zooplankton

Nekton:

common fish, whales, squid, etc.

Benthos:

starfish, clams, snails, etc.

Marine animals can be divided

into 3 groups:



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Rivers and streams

algae

aquatic

birds

stork

reeds

dragonfly

trout

otter



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Lagoons and marshes

fish

ducks

frog

snake

cattails

heron



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Valuation of biodiversity

High

Forests

Low

Cultivated land

Very

high

Rainforest

Very

high

Meadows



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Valuation of biodiversity

High

Very

high

Eels /anguila

Chive /cebollino

Otters/ nutria

Reeds/ junco

Barbels/barbo

Wagtail/lavandera

Water-plantain/llanten de

agua

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Módulos de trabajo para Seminarios del Tema 1 Introducción ... · 04/04/2020 · Biocenosis (community) Biotope Biotic factors Abiotic factors Unit 12 Unit 12 An ecosystem refers