The structure of ecosystems

Autora: Marta García T.

THE ENVIRONMENTIt refers to all biotic and abiotic (physical and

chemical) conditions at a certain place.


Factores Limitantes:

Rango de Tolerancia.Zona Óptima.


BIOTIC FACTORS


BIOTIC RELATIONSAre interactions among the living things in an

ecosystem. There are two types:

1.Intraspecific Relations: among organisms of the same species.

2. Intersepecific Relations: among organisms of different species.


Intraspecific Relations:

Familial: groups of related individuals which live together.

Gregarious: groups of individuals which live together for some time to get a benefit.

Colonial: related individuals live physically fixed.

Social: groups of organisms organised to do different jobs for the comunity.


What kind of intraspecific relation…?

Familial

Social

Colonial

Gregarious


Interespecific Relations:

Depredation: predator kills and eats the prey.Parasitism: parasite lives at the expense of the

host, and harms it.Mutualism: two individuals get mutual benefit.Commensalism: one individual gets benefit, but

the other is not affected.Inquilinism: one species, the inquiline, makes

use of a host's nest or habitat without causing any detriment to the host.

Competition: the interaction between two or more organisms, or groups of organisms, that use a common resource in short supply.


What kind of interespecific relation….?

Parasitism Depredation Mutualism Commensalism


Parasitism Inquilinism Competition Commensalism



WHAT IS AN ECOSYSTEM?Ecosystem = Biotope + Biocenosis

Biotope: is the inorganic part (non living things) in an ecosystem.

Biocenosis: is the set of living things in an ecosystem.


Biomes are the large-scale ecosystems of the world (desert, rainforest, tundra, taiga, grassland, mediterranean forest and deciduous forest).

http://recursos.cnice.mec.es/biosfera/alumno/2ESO/Energia_ecosistemas/actividad3.htm

Biosphere includes all the living things of the world.

Ecosphere includes all the ecosystems of the world.


TERRESTRIAL ECOSYSTEMSAre ecosystems where organisms can live

on land, surrounded by air. They can be natural or man-made.

The distribution of organisms depends on abiotic factors, which are related to the climate:

Temperature.Light.Humidity.


There are three large climate zones in each hemisphere, and we can find different biomes in them:

Frigid ZoneTemperate ZoneTorrid Zone


Match the columns

CLIMATE ZONES ECOSYSTEMS

Frigid Zone

Temperate Zone

Torrid Zone

DessertGrasslandTundraDecidous ForestTaigaRainforestMediterranean Forest

http://www.kidsknowit.com/interactive-educational-movies/free-online-movies.php?movie=biomes


AQUATIC ECOSYSTEMSThey are ecosystems where organisms

live sorrounded by water. The main abiotic factors are:

Light. Temperature. Salinity. Oxygen. Pressure. Density. Water Movements. Viscosity.


How do you think these factors vary with depth?

Ligth __________ with depth.

Pressure __________ with depth.

Temperature __________ with depth.

Oxygen __________ with depth.


There are two types of aquatic ecosystems:

1.Freshwater Ecosystems: with less salinity. Ex: rivers, lakes, marshes.


2. Marine Ecosystems: more salty. We can find three types of organisms:

Plankton: tiny plants and animals of the ocean that serve as food for ocean creatures.

Necton: animals that can move freely up and down in the water.

Bentos: plants and animals who live on the ocean floor.


Plankton, bentos or necton?


Flippers to help it swim.

Streamlined shape.

Thick layer of body fat to keep it warm.

Strong teeth to catch fish.

Forward-facing eyes for clear vision ahead.

Hind legs have evolved into a a strong rudder-like tail.

How is the seal adapted to its environment?


Which is the Habitat for each organism?

Artic BearCamelParrotRabbitCrabMarmotIlexSharkTrout

DesertRainforestPolesMediterranean

ForestGrasslandCoastlandOceanRiver



HOW DO LIVING THINGS OBTAIN FOOD?

All living things can be classified according to the way they obtain food. These are the Trophic Levels (3).

Where do they obtain their food from?:


1. ProducersProducers make their own food organic

matter) from carbon dioxide, water and mineral salts. They have autotrophic nutrition. Plants, algae and some bacteria are producers.


2. ConsumersConsumers eat (consume) food provided by

plants or other animals. They have heterotrophic nutrition.

There are three types of consumers. Can you guess?


Herbivores are called Primary Consumers. They only eat producers.

Secondary Consumers can be carnivores or omnivores.

Tertiary Consumers feed on primary and secondary consumers. Some of them feed on producers, as well.


Some animals are predators, some are prey, some are both.

The predator eats the prey, and the prey gets eaten by the predator.


3. DecomposersThey decompose organic matter (dead animals

and plants) into inorganic matter. This inorganic matter (mineral salts) is used again by producers.

Bacteria and fungi are decomposer.


Food ChainsA food chain shows which plants or animals eat or get eaten by others, in an ecosystem.

The _______ gets eaten by the _______.


The _______ is eaten by the _____, the ____ is eaten by the ____.

The _______ is eaten by the _____, the ____ is eaten by the ____.



• A set of food chains is a Food Web.

1. Take three food chains

from this food web.

2. Identify the producers, primary consumers,

secondary consumers, tertiary consumers, herbivores, carnivores and omnivores.


When a member of the trophic web varies in number, the others organisms get affected as well.

http://puzzling.caret.cam.ac.uk/game.php?game=foodchain

http://www.ngfl_cymru.org.uk/vtc/Phase3delivery/Wales/Science/Keystage4/Livingthingsand/Feedingrelation/Introduction/default.htm



So, matter describes a closed cycle in the ecosystem. It is recycled, but not lost.


HOW IS ENERGY TRANSMITTED IN THE ECOSYSTEM?Energy gets into the food chain from the sun,

and pass through the trophic levels. But it cannot be recycled, because all living things consume energy. So, some energy gets lost as heat.


Where do energy come from?

Does it go back?So, does it

describe a closed cycle?


TROPHIC PYRAMIDSA trophic pyramid is a graphic representation

of a particular characteristic at each trophic level.

Each trophic level is represented by layers of equal height.


Number Pyramid: represents the number of individuals at each trophic level:

In this ecosystem there are…:

______ Secondary Consumers

______ Producers______ Primary Producers______ Tertiary

Consumers


Draw this ecosystem’s number pyramid:

Grass and trees: 10.000Butterflies and Grasshoppers: 500Rabbits: 50Rats: 50Snakes: 10Eagles: 2


Biomass Pyramid: shows the biomass at each trophic level of a food chain.

Energy Pyramid: shows the energy contained in each trophic level.

Can you think of ecosystems where…:

1.Number Pyramid could be inverted?2.Biomass Pyramid could be inverted?3.Energy Pyramid could be inverted?


HÁBITAT VS NICHO ECOLÓGICOEl Hábitat es el lugar en el que habita una

especie.El Nicho es el papel que desempeña una

especie en un ecosistema, considerando:

- Relaciones tróficas.- Relaciones con el ambiente.- Funciones ecológicas.



Es la capa más superficial de la corteza terrestre, interfase entre la geosfera, la atmósfera, la hidrosfera y la biosfera.

Componentes:

Inorgánicos: agua, gases, arenas, gravas, arcillas, y sales minerales.

Orgánicos: seres vivos y humus (materia orgánica en descomposición).


FORMACIÓN DE UN SUELO

Etapa inicial: meteorización de la roca madre. Formación del "manto de alteración". Colonización biológica.

Etapa de maduración: la actividad de los seres vivos proporciona materia orgánica que se transforma, dando lugar al humus. La evolución del suelo permite la instalación de comunidades biológicas más complejas.

Etapa climácica: el suelo queda estructurado en

niveles horizontales denominados horizontes.



FACTORES EDAFOGENÉTICOS

Clima: agentes geológicos externos.Topografía.Características de la Roca Madre.Actividad Biológica.Tiempo: 1 cm – 500 años.Actividades Humanas.


PERFIL DEL SUELOHorizontes:

Horizonte A: de lixiviado, pobre en minerales, rico en humus y materia orgánica viva. Oscuro.

Horizonte B: de precipitación. Color pardo.Horizonte C: de transición. Fragmentos

procedentes de la alteración de la roca madre.Roca Madre inalterada.



DEGRADACIÓN Y PÉRDIDA DEL SUELO: DESERTIFICACIÓN.

Deforestación.Prácticas Agrícolas no Sostenibles.Sobrepastoreo.





BOSQUE ATLÁNTICOClima moderado, abundantes lluvias.Caducifolio (hayedos, robledales).Sotobosque muy desarrollado.Fauna variada.


BOSQUE MEDITERRÁNEOClima mediterráneo de interior.Plantas adaptadas a la sequía estival.Fauna variada.Dehesa.



LOS RÍOSDiferenciación de flora y fauna:

Curso Alto.Curso Medio.Curso Bajo.


LOS LAGOSMasas de agua profundas.Origen glaciar.Dinámica Lacustre.


LOS HUMEDALESEcosistemas frágiles.Zonas inundadas.Recarga subterránea.Salinidad.Zonas ZEPA.


ZONAS MARINASLitoral Cantábrico Litoral Mediterráneo


PRADERAS DE POSIDONIA


Education

The structure of ecosystems