Ecology review:

What is Ecology? (a brief review)

Ecology- the study of interactions between –organisms and organisms –organisms and their environment

Where do we fit in? (What is our environment?) The Biosphere!

Factors that effect us: 1. Abiotic Factors Wind/Air currents Moisture Soil Light Temperature

A- stands for non Bio- stands for living Abiotic Factors- nonliving factors

2. Biotic Factors:

Biotic- Living factors

What is the organization of Ecological Study? Population Community Ecosystem Biosphere Organism

Levels of Organization Individual- one organism (living) Ex a moose

Levels of Organization Population- groups of individuals that belong to the species and live in the same area. (living-living same species) Ex many moose

Levels of Organization Community- groups of different populations (more than one population or different groups of species) Ex many groups of moose beavers, trees, grass (all living)

Levels of Organization Ecosystem- all organisms in a particular area along with the nonliving. (living and nonliving) Ex many groups of moose beavers, trees, grass, rocks, water, mountains

Levels of Organization Biome- group of ecosystems that have the same climate and similar dominant communities Biomes: tropical rain forest, tropical dry forest, tropical savannah, temperate grassland, desert, temperate woodland and shrubland, temperate forest, northwestern coniferous forest, boreal forest (taiga), tundra, mountains and ice caps

Levels of Organization Biosphere- all of the planet where life exhists, includes land, water, and, air Life extends 8 km up and 11 km below the surface

IN AN ECOSYSTEM: Organisms live in a Habitat Organisms fit into a Niche of the environment

Habitat vs. Niche Habitat- an area where an organism lives Niche- an organisms role in its environment –The Long Version  full range of physical and biological conditions in which an organism lives and the way in which the organism uses those conditions. Includes where in the food chain it is, where an organism feeds Habitat is like an address in an ecosystem and a niche is like an occupation in an ecosystem.

ENERGY FLOW Autotrophs vs. Heterotrophs

Energy Flow (Trophic Levels) Producers- make their own food Consumers- get energy from consuming producers

Producers Producers- capture energy from sunlight or chemicals and use the energy to produce food. Producers are autotrophs- they make food from their environment

2 main types of autotrophs One type gets energy from the sun-by photosynthesis Another type gets energy without light- by chemosynthesis

Consumers Consumers are heterotrophs- get energy from other organisms

Types of Consumers Herbivores- eat only plants Carnivores- eat animals Omnivores- eat both plants and animals Detritivores- eat dead matter (plants and animals)

Feeding Relationships Energy flows through an ecosystem in one direction from: –1. the sun or inorganic compounds –2. To autotrophs (producers) –3. To heterotrophs (consumers) –Decomposers get energy from decomposing dead organisms

Food Web- A network of feeding relationships. (More realistic that a food chain) Food Chain- a series of steps in which organisms transfer energy by eating or being eaten.

Food Web

They can become very complex!

Trophic levels Each step in a food chain or a food web is called a trophic level. –Producers are the first trophic level –Consumers are the second, third, or higher trophic level Each trophic level depends on the one below for energy

Energy Pyramid Only part of the energy stored in one level can be passed to the next- most energy is consumed for life processes (respiration, movement, etc., and heat is given off) Only 10% of the energy available within one trophic level is transferred to organisms in the next trophic level

Biomass Pyramid Biomass- the total amount of living tissue within a given trophic level. A biomass pyramid represents the amount of potential food available for each trophic level in an ecosystem.

Energy Losses Energy transfers are never 100 percent efficient Some energy is lost at each step Limits the number of trophic levels in an ecosystem Energy flow is a one way path! (not a cycle)

All Heat in the End At each trophic level, the bulk of the energy received from the previous level is used in metabolism This energy is released as heat energy and lost to the ecosystem Eventually, all energy is released as heat

All living organisms need certain elements/compounds for life processes –Ex: your cells need C,H,O,P,N & S in order to live and reproduce (make more cell) Cycles in nature keep these elements “moving” from organisms to organism (and sometimes into the atmosphere) Biogeochemical Cycles (Matter moving through the environment)

The flow of a nutrient from the environment to living organisms and back to the environment Main reservoir for the nutrient is in the environment Transfer rates to and from reservoir are usually lower than the rates of exchange between and among organisms. Matter is recycled through an ecosystem – not one way flow

Three Categories Hydrologic cycle –Water Atmospheric cycles –Nitrogen and carbon Sedimentary cycles –Phosphorus and sulfur

CYCLES IN NATURE

Carbon Cycle Carbon moves through the atmosphere and food webs on its way to and from the ocean, sediments, and rocks Sediments and rocks are the main reservoir

Carbon Cycle photosynthesis TERRESTRIAL ROCKS volcanic action weathering diffusion Bicarbonate, carbonate Marine food webs Marine Sediments Atmosphere Terrestrial Rocks Soil Water Peat, Fossil Fuels Land Food Webs

Carbon in Atmosphere Atmospheric carbon is mainly carbon dioxide Carbon dioxide is added to atmosphere –Aerobic respiration, volcanic action, burning fossil fuels, decomposition of organic materials Removed by photosynthesis

Nitrogen Cycle Nitrogen is used in amino acids and nucleic acids (all living organism need nitrogen to make proteins) Main reservoir is nitrogen gas in the atmosphere Decomposers are vital to convert ammonia into: 1. usable nitrites & nitrates for plants (nitrogen fixation) 2. nitrogen gas (denitrification = puts it back into the atmosphere)

Phosphorus Cycle Phosphorus is part of phospholipids and all nucleotides –What are these? It is the most prevalent limiting factor in ecosystems Main reservoir is Earth’s crust; no gaseous phase (it never enters the atmosphere – like carbon and nitrogen)

Phosphorus Cycle GUANO FERTILIZER ROCKS LAND FOOD WEBS DISSOLVED IN OCEAN WATER MARINE FOOD WEBS MARINE SEDIMENTS excretion weathering mining agriculture uptake by autotrophs death, decomposition sedimentationsetting out leaching, runoff weathering uplifting over geolgic time DISSOLVED IN SOILWATER, LAKES, RIVERS uptake by autotrophs death, decomposition