Fundamental concepts in ecosystems: Biological communities, biological populations, autotrophs, heterotrophs, photosynthesis, respiration, food chain, energy flow, biogeochemical cycles

1. Energy flow in ecosystemsEnergy flow in ecosystems
Earth compartmentsEarth compartments
Biogeochemical cyclesBiogeochemical cycles
Sustainable DevelopmentSustainable Development
Carlos LoyolaCarlos Loyola
Saltillo Institute of TechnologySaltillo Institute of Technology
(U2) Natural Dimension(U2) Natural Dimension
EcoEcosyssystemstems

2. Ecosystem: TheEcosystem: The biological communitybiological community of interactingof interacting
organisms and their non-living environment.organisms and their non-living environment.
Picture of a freshwater ecosystem, with aquatic plants, fish, and other livingPicture of a freshwater ecosystem, with aquatic plants, fish, and other living
organisms, interacting with soil, water, light, etcétera. The pond is located inorganisms, interacting with soil, water, light, etcétera. The pond is located in
Cuatrocienegas, Mexico. Photo by: Daniel Garza Tobón.Cuatrocienegas, Mexico. Photo by: Daniel Garza Tobón.

3. Biological community:Biological community: All of theAll of the populationspopulations livingliving
and interacting within a particular geographic areaand interacting within a particular geographic area.
The picture shows members of variousThe picture shows members of various
biological populations: severalbiological populations: several
epiphyte plants, the tree hosting theepiphyte plants, the tree hosting the
epiphytes, and theepiphytes, and the ““resplendentresplendent
quetzalquetzal”” ((Pharomachrus mocinnoPharomachrus mocinno).).
This biological community live in theThis biological community live in the
biosphere reservebiosphere reserve ““El TriunfoEl Triunfo””, in the, in the
Mexican state Chiapas. Photo by:Mexican state Chiapas. Photo by:
Daniel Garza Tobón.Daniel Garza Tobón.

4. Biological population:Biological population: a group of individuals of thea group of individuals of the
samesame speciesspecies living and interbreeding within aliving and interbreeding within a
given area.given area.
Picture of a population of the American white pelican (Picture of a population of the American white pelican (PelecanusPelecanus
erythrorhynchoserythrorhynchos) Photo by: Daniel Garza Tobón.) Photo by: Daniel Garza Tobón.

5. Species:Species: Members of populations that actually orMembers of populations that actually or
potentially interbreed in nature, not according topotentially interbreed in nature, not according to
similarity of appearance.similarity of appearance.
Photo: http://www.labartolinadecananea.com.mx/cananea/2017/08/10/mude-salva-al-lobo-mexicano/
Family members of the Mexican wolf (Family members of the Mexican wolf (Canis lupus BaileyiCanis lupus Baileyi), a subspecies of the), a subspecies of the
grey wolf (grey wolf (Canis lupusCanis lupus))
http://www.iucnredlist.org/details/classify/3746/0

6. Types of organisms:Types of organisms: according to the way they feed themselvesaccording to the way they feed themselves
AutotrophsAutotrophs synthesizesynthesize
their own food fromtheir own food from
inorganic sources (usinginorganic sources (using
sunlight or chemicalsunlight or chemical
energy). They are theenergy). They are the
producersproducers of food in theof food in the
ecosystem. (Plants, algi,ecosystem. (Plants, algi,
other)other)
HeterotrophsHeterotrophs dependdepend
upon the energy andupon the energy and
carbon fixed by somecarbon fixed by some
other organism. They areother organism. They are
consumers, detritivores,consumers, detritivores,
or decomposers.or decomposers.
(Animals, fungi, other)(Animals, fungi, other) Photo: Jesús García JiménezPhoto: Jesús García Jiménez
Photo: Carlos LoyolaPhoto: Carlos Loyola

7. PhotoPhotosynsynthesisthesis
During the photosynthesis process, the plants (autotrophs) convert the energy from
photons (in sunlight) onto chemical energy, synthetizing carbohydrates or sugars
(C6H12O6). The process is run by electrons and protons from the hydrogen in water
molecule, which is split apart, releasing oxygen as waste. During the respiration
process, animals (and other heterotrophs) use the chemical energy stored in
carbohydrates to perform biochemical work. During respiration, animals oxidize
carbohydrates and release carbon dioxide and water.

8. http://bioap.wikispaces.com/Ch10+Collaboration
PhotoPhotosynsynthesisthesis

9. H2O
O2
CO2
C6H12O6
NADP’
ADP
ATP
NADPH
Calvin
Cycle
Light
Rxn
Pi
http://bioap.wikispaces.com/Ch10+Collaboration
PhotoPhotosynsynthesisthesis
Photon
Over simplified diagram of photosynthesis. Water provide critical protons and electrons
contained in the hydrogen atom. Oxygen is wasted outside the cell. Adenosine
Triphosphate (ATP) and Reduced Phosphorilated Nicotine Adenine Dinucleotide
(NADPH) provide chemical energy that run the cycle where carbon dioxide is combined
to simpler sugars then producing 6-carbon carbohydrates like glucose (C6H12O6)
CH2O

10. Food chainFood chain
Saprophagus
Decomposers
The sequence ofThe sequence of ““whowho”” produces,produces,
consumes or degrades foodconsumes or degrades food
Once plants (primary producers) synthetize food in the form of carbohydrates and
other organic compounds, they can be eaten by herbivores, which are the source of
food for carnivores and so on in the food chain.

11. The Energy PyramidThe Energy Pyramid
Tertiary
Consumers
Primary
Producers
Approximately 10% of the energy that is harvested in a
level, passes to the upper one
1,000,000 J from sunlight1,000,000 J from sunlight
EcoEcosystesystemsmsEnergy flowsEnergy flows
Secondary
Consumers
Primary
Consumers

12. EcoEcosystesystemsmsEnergy flowsEnergy flows

13. Foto: Daniel Garza Tobón
AtmosphereAtmosphere
Earth compartmentsEarth compartments
HydrosphereHydrosphere
LithosphereLithosphere
BiosphereBiosphere
Chemical compounds are cycled along the compartments of planet Earth, in what are
called Biogeochemical cycles.
Biogeochemical CyclesBiogeochemical Cycles

14. The Carbon cycle is considered a gaseous cycle; with huge amounts of this chemical
element being circulated in a gaseous form along the atmosphere; but with
considerable amounts being stored in the biosphere, lithosphere and the
hydrosphere.
Biogeochemical CyclesBiogeochemical Cycles
Photo: https://commons.wikimedia.org/wiki/File:Carbon_cycle-cute_diagram-espanol.svg
The Carbon CycleThe Carbon Cycle