ECOSYSTEM COMPONENTS: ENERGY FLOW & MATTER CYCLING

ECOLOGY  Study of the relationships between organisms and their environment  How organisms interact with their nonliving environment such as sunlight, temperature, moisture, nutrients, etc.  KEY WORD IS: INTERACT - Connections in Nature  What is an organism?  What make up organisms?

Organisms are either:  EUKARYOTIC -  SURROUNDED BY A MEMBRANE  HAVE A DISTINCT NUCLEUS  HAVE INTERNAL ORGANELLES  All organisms except bacteria.  PROKARYOTIC -  SURROUNDED BY A MEMBRANE  NO DISTINCT NUCLEUS  NO INTERNAL PARTS SURROUNDED BY MEMBRANES  Bacteria

Population  A group of organisms of the same species in a given area at a given time  Can vary with: season, time of day, time of year  Density = number of organisms/area  What is genetic diversity?

What is a habitat?  Where an organism lives

What is a Community?  Populations of all species in a particular place at a particular time.

What is an Ecosystem?  Community of different species interacting with one another and with their nonliving environments.  Ecosystems can be small or large.  What is the Biosphere?

Lithosphere: crust and upper mantle; contains fossil fuels, minerals, and soil chemicals Hydrosphere: earth’s water Atmosphere: thin layer of air Biosphere: all living things Trophosphere: 17 km above sea level, contains most of the planet’s air Stratosphere: km above sea level, contains ozone Core: liquid and solid iron, generates the earth’s protective magnetic field Mantle: liquid rock and metal, source of geothermal energy

Biosphere is sustained by:  One -way flow of energy - from sun through plants to animals - then back into space  Cycling of matter or nutrients  Gravity - allows planet to hold its atmosphere  Organisms are open systems  exchange matter and energy between the system and the environment  Take in matter and energy - use it to stay alive and put waste back into the environment.

How does the sun sustain life?  Lights & warms the planet  Supplies energy for photosynthesis  Powers cycling of matter  Drives the climate and weather systems  Facts about the sun:  Middle- aged star  Takes 8 minutes for light to get to the earth  Most of light to earth is ultraviolet  About 28% of its light is reflected back into space by clouds, dust, and land  72% warms air and land, evaporates water, generates winds,  Only about.023% is used by plants for photosynthesis

Seasons

Latitude  What affects will latitude have on light and heat availability?

Nutrient Cycles  Nutrient - any atom, ion or molecule an organism needs to live  Macronutrients are needed in large amounts - CHONPS and a few others  Micronutrients - needed in small or trace amounts.  Also called Biogeochemical cycles  Driven by the sun  Main ones are hydrologic, nitrogen, carbon, phosphorus, and sulfur.

Ecosystem Concepts  Biotic - living components - plants and animals  Abiotic - nonliving components - water, nutrients, air, solar energy, etc.

Range of Tolerance  Ability to survive within variations of a physical or chemical environment  Individuals within a population may have differing ranges of tolerance Population Size LowHighTemperature Zone of intolerance Zone of physiological stress Optimum range Zone of physiological stress Zone of intolerance No organisms Few organisms Lower limit of tolerance Abundance of organisms Few organisms No organisms Upper limit of tolerance

Limiting Factors  Any one factor that is responsible for regulating population growth  Light, water  In aquatic ecosystems  D.O.  Sunlight  Temperature