Energy and Biogeochemical Cycles

ENERGY

  • Defined as the capacity to do work
    • In order for work to be done, there has to be an Input, and that input should be in the form of Energy
  • Work → Displacement of any body against an opposing force
    • In order for work to proceed, a displacement or movement within a system needs to take place
    • Work is the product of force and the distance displaced
    • There should always be an input of Force, which is the ultimate reason behind the displacement of a particular object
  • In Biology, work describes any displacement against any force that living things encounter or generate
    • Example of a Biological Process that uses Work: Process of OSMOSIS
  • The process of work is facilitated by energy
  • The energy that fuels the work to be done in a given living system is NOT compartmentalized to that system alone
    • Hence, energy can and must be passed and transformed from one form in one system to another system in order for that system to facilitate work and serve their purpose in the entire ecosystem

THE ENERGY PYRAMID

  • Cannot be inverted in form, should always be Upright
    • From primary producers (at the base), the percentage of energy decreases
  • This cannot be inverted as there is a pattern with regard to the reduction of the percentage of energy across the levels
  • Energy Pyramid Pattern: 10% RULE
    • 10% of the energy is transferred from one trophic level to the next trophic level
    • This rule underlies the open property of living systems
    • The remaining 90% of energy WAS NOT transferred to the next trophic level. There can be two possible explanations:
    • 2nd Law of Thermodynamics
      • States that the entropy of a given system always increases
      • The transfer of energy to another system will always increase until the release of heat. The release of heat then corresponds to the release of entropy.
      • Hence, some of the 90% of energy are released as heat to the environment
    • A huge chunk of the energy not transferred to the next system (trophic level) was used by the system to fuel its processes
      • There is a correlation between two types of metabolism
      • Anabolism → the building up procedure
      • Complex polymers are synthesized out of the simpler monomeric subunits
      • Ex: Photosynthesis
      • Catabolism → the breaking down procedure
      • Complex polymer is broken down into its monomeric subunits
      • Ex: Process of aerobic respiration

BIOGEOCHEMICAL CYCLES

  • The System as a Closed System

    • Closed System → one in which matter, not energy, is cycled within a given system
    • Matter, is compartmentalized in a closed system
    • In order for living systems to do this, they must have a process in which the physical and chemical components cycle within the system
    • This process is called the BIOGEOCHEMICAL CYCLE

    BIOGEOCHEMICAL CYCLE

    • A series of interrelated events that cycle biological, geological, and chemical components in an ecosystem
    • Definition → The movement of chemicals elements from biotic (organisms) to abiotic (atmosphere, marine, and fresh waters, soils, and rocks) components and vice-versa
    • From Biotic (organisms that utilize chemical elements) to Abiotic Components (to the immediate environments wherein these chemicals are to be deposited), and vice-versa

Importance of Biogeochemical Cycles

  • Allows the transformation of matter to different forms (useful for a particular organism)
    • Significant → there is an involvement of the biological key players, which are the organisms themselves
    • The organisms are involved primarily.
    • They are the ones that assimilate and process these elements into other forms
  • Links living organisms with living organisms, and living organisms with abiotic factors
    • Interconnections within the ecosystems are vital to every given system
    • Hence, biogeochemical cycles provide a linkage between the living organisms with their co-living organisms and abiotic factors
    • In this way, the elements are transformed from one form to another via these interactions
  • Enables the movement of elements from one locality to another
    • Composition of the abiotic components of the ecosystem
    • Whenever these elements move from one locality to another, they become part of the localities serving a particular purpose
  • These (three) importances take part in establishing the dynamics in certain types of systems (i.e., in Populations)

DYNAMICS IN POPULATIONS: REGULATING MECHANISMS

  • Refers to changes that take place in these populations

  • Ecosystem Feedback

    • Changes in one part of a living system allows for changes in another system
    • The ecosystem feedback is a counter-bouncing effect that helps regulate the overall state of the ecosystem
    • Two Forms → Negative Feedback and Positive Feedback
    • In both, an input process, output, and feedback take part in the regulation of the overall state of the ecosystem
    • The Negative Feedback Mechanism negates the effect of the stimulus or input.
    • The Positive Feedback Mechanism further reinforces or enhances the effect of the stimulus or input.

  • Example: Population Regulatory Mechanisms

    • Population regulation is form of Negative Feedback Mechanism
    • The population size of the predator serves as the stimulus or input which negates the population size of the prey
    • The negative feedback mechanism serves as a source of stability for the entire population
      • Because it maintains the population size of prey at a certain acceptable level or range that the environment can sustain
      • Sustains Carrying Capacity of the environment (hence, it is a source of stability)

    \n

    \n