Environmental Systems - Basics

Environmental Systems - Basics

1. The function of systems

   • emergent properties - a characteristic set of behaviours produced by system processes
     • a property the system has but not individual components

2. The composition of systems

   • stores of matter
     • carbon in plants
     • organic matter/nutrients/minerals in soil
   • flows - inputs/outputs
     • movement of water, solids, energy
   • processes - conversion
     • photosynthesis, oxidation of organic matter, chemical weathering
   • feedback mechanisms
     • negative - provides stability and resists change
     • positive - produce change

3. Key characteristics of systems

   • purpose
   • components
     • 'parts' that make up the system
   • interconnections
     • relationships linking components
   • structure
     • the systems 'pattern of organisation' determines a systems identity
   • processes
     • activities occurring in the systems to achieve the overall purpose

4. Socio-ecologcial systems

   • components and processes are natural and human
     • complimentary - not damage natural processes and/or help damamged
     • antagonistic - damage/destroy habitats or processes
   • generally complementary is seen as sustainable
     • spatial and temporal view alters this

5. Inputs and outputs

   • inputs (resources) can be finite or renewable
     • renewable resources are process-limited
     • non-renewable resources are component-limited
   • outputs can be removed from a system, or assimilated into a system therby changing the inherent nature of the system

6. Components and proceses

   • abiotic components - physical and chemical factors
     • represent geological, geographical, hydrological and climatological features of a particular ecosystem
   • biotic components - living organisms, classified after the way they get thier food
     • autotrophs produce food for themselves and others
   • processes control the rate of the inputs and outputs
     • these processes generally have rules associated with them and are themselves affected or driven by variables