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The structure of an
ecosystem.
What is the biosphere and
the ecosphere?
Biosphere - Ecosphere
Biosphere: is the life zone of the Earth. It includes all
living things and organic matter.
Biosphere is the living component or the ecosphere.
Ecosphere includes the large-scale ecosystems of the
world.
An ECOSYSTEM is a section of the biosphere formed
by living organisms, the relationships between them
and the physical environment.
Biomes - ecosystems
Biomes are the large-scale ecosystems of the world.
An ecosystem can be as small as a puddle or as large as
an ocean.
Ecosystem: biocenose +
biotope
Components
Ecosystems have two components:
1.Biocenose: the set of living beings in the ecosystem:
animals, plants, fungi, and all types of microorganisms.
Biotic factors are the effects which other organism have
on a living being in its environment.
Components
2.- Biotope: is the inorganic part of the ecosystem, the
physical environment. Abiotic factors are the physical
and chemical elements in an ecosystem which affect
living organisms. It includes: temperature, humidity,
soil, energy, pollution…
Tolerance limits are the values of a particular abiotic
factor which must not be exceeded if a species can
survive.
Living organisms can resist some variations in those
factors, but sometimes a change in a factor can be vital
and can be the reason for desappearing. Ex: temperature
or humidity. The factor is called LIMITING FACTOR and
has less tolerance
Examples of abiotic factors:
Temperature
Light
Humidity
Pressure
Salinity
Oxygen
Water
Soil
Climate zones
Levels of plants in a forest
How do living things obtain
food?
Living organisms can be classified according to the way
they obtain food. It determines their trophic level, that is
their place in a food chain.
Producers
Producers:
They are the living beings which make their own
organic matter from carbon dioxide, water and mineral
salts (inorganic matter).They use the energy of the Sun
during photosynthesis.
This is autotrophic nutrition.
Plants, algae and some bacteria.
Consumers
Consumers
Consumers
Consumers:
They are living beings that cannot produce their own
organic matter. They feed on organic matter produced
by other living beings.
This is heterotrophic nutrition.
Primary consumers: Feed on producers: Herbivores.
Secondary consumers: carnivores
Tertiary consumers: feed on primary and secondary
consumers and producers.Omnivores
Decomposers: They decompose organic matter into
inorganic matter.
Habitat and niche
Habitat is the physical place where a species lives.
An ecological niche is the way a species relates to the
biotic and abiotic factors in an ecosystem.
Giraffes and zebras live in the same habitat, but they
occupy different ecological niches.
Habitat and niche
Trophic dynamics
Is the system which describes the position of a living
being in a food chain. It is the system that explains what
an organism eats or is eaten by.
It is represented by a food web.
Food web:
Food web
Biotic relations:
The interactions among the living beings in an
environment.
There are two types:
Interspecific
Intraspecific
Mutualism
Commensalism
Inquilinism
Parasitism
Depredation
Interspecific:
Interactions among organisms of different species.
1.Mutualism. Two organisms for mutual benefit. (Bees
and flowers)
2.Commensalism: One benefits and the other is not
affected. (Beetles and mammal excrements)
3.Inquilinism: One organism uses the other for housing
(crabs and shells)
4.Parasitism: A parasite lives at the expense of a host and
harms it. (Cochineals on plants)
5.Depredation: A predator kills and eats a prey.
Gregarious
Colonial
Social
Familial
Intraspecific relations
Interactions among organisms of the same species.
1.Gregarious: Groups of individuals that live together for
some time to provide mutual help. (migrating birds)
2.Colonial: Related individuals live together. Coral
3.Social: Groups of individuals organized in a hierarchy.
(Ants)
4.Familial: Groups of related individuals which live
together to procreate and protect the young.
ADAPTATIONS
Adaptations refer to the adjustment which species make over millions of years
of evolution in order to manage their relationship with the environment.
Types of adaptations:
-Morphological: relate to the body structure (size)
-Physiological: affect the internal management of the organism (body temp.)
-Behavioural: relate to behaviour ( migration…)
Living organisms have to adapt to: temperature, humidity and to light.
ADAPTATIONS
Living organisms adapt to their invironment:
-Plants transform some leaves into spines, or store water or have a hard leaf
cover to avoid transpiration…
-Animals store fats under the skin for protection, or reduce the ear size to
minimize the heat loosing, or ….do you imagine any other adaptation?
Biomes:
A biome is a set of terrestrial ecosystems that, due to sharing similar climatic
conditions, have a similar biocenosis.
1.
2.
3.
Frigid zone: cold zones from the Poles to
the polacr circles.
Temperate zones: between the polar
circles and the Tropics.
Torrid zone: between the Tropic of
Cancer and the Tropic of Capricorn.
Frigid zone:
Tundra:
Permanently frozen soil
Mosses, lichens
Reindeer, white foxes, lemmings
Taiga:
Long, dark, cold winter
Short humid summers
Pine and fir trees
Bear, lynxes, wolves
Temperate zone: (SPAIN)
Deciduous forest or atlantic
Cold and warm seasons, abundant rainfall, and mild
temperatures
Oak, beech, chestnuts trees (deciduous species with large leaves)
Bears, foxes, squirrels, mountain lions, roe, genet, tritons, etc
Mediterranean forest:
Warm dry summers, low rainfall, droughts
Holm oaks, cork oaks (perennail leaves, which are small and
hard), aromatic plants
Rabbits, reptiles, wild boars, birds
Mediterranean shrubs :
Modification of the forest in extremely hot temperatures. Types:
Maquis (rockrose, mastic and myrtle) and garriga (palm, thyme,
lavender)
Aquatic biomes:
Creatures can live surrounded by water.
Abiotic factors:
Light: it decreases as the water gets deeper.
Temperature: it varies with distance from the coast and the depth
of water
Pressure: increases as the water gets deeper
Salinity: it varies in aquatic ecosystems
Oxygen: A E have less oxygen and fewer gases
Photic ZONE: area closest to the surface
Bathyal ZONE: not much light and higher
pressure
ABYSSAL PLAIN: high pressure, temperature
around 2-3 ºC. Little food and very little light
reaches the sea floor
Aquatic biomes:
Freshwater
0.3 % of the surface is contained in fresh water ecosystems.
Salinity: 0.18 g/L
TYPES:
Lentic : still water
Lotic: running water
Marine:
About yhe 97% of water on Earth.
Temperature in tropcal areas: 32 ºC, polar
regions: -2ºC
Salinity: 35 g/L
Classification according to depth and distance
from the coast.