Ecology how organisms interact with each other and the nonliving environment.

We share the Earth…

with a whole lot of other creatures…

We don’t share very well….

Ecology Putting it all together… –the study of interactions between creatures & their environment is important because… Everything is connected to everything else

Ecosystem Living (Biotic) factors –all plants, animals, and decomposers living in an area Physical (Abiotic) factors –soil, rock, temperature, moisture, sunlight (NONLIVING FACTORS) habitat = address (where you live) niche = job (the role you play) THE INTERACTION OF THE LIVING AND NONLIVING IN A PART OF THE ENVIRONMENT

Name 3 Abiotic Factors and 3 Biotic Factors ABIOTIC clouds, atmosphere, water, carbon dioxide, oxygen, dirt, sun BIOTIC deer, frog, ducks, fox, birds, grass, trees

many of the same organisms living together different populations living together a community and the abiotic environment the “layer” of Earth where life exists LEVELS OF ECOLOGICAL ORGANIZATION a living thing

The BIOSPHERE THE LAYER OF EARTH WHERE LIFE EXISTS

Populations MANY OF THE SAME ORGANISMS LIVING TOGETHER

A COMMUNITY DIFFERENT POPULATIONS LIVING TOGETHER LIONS ZEBRAS (well…maybe not!) VULTURES GRASS

EARTH’S LAND ECOSYSTEMS (BIOMES) A COMMUNITY AND THE ABIOTIC (NONLIVING) ENVIRONMENT

What do ecosystems require in order to maintain stability? Constant Energy Source Producers to convert light energy into chemical energy (organic compounds - PHOTOSYNTHESIS) Nutrients to be recycled (C, N, H2O, P, S) (decomposers)

Feeding relationships –all food chains start with energy from the sun –first level of all food chains is plants (producers) –most food chains usually go up only 4 or 5 levels –all levels connect to decomposers Food chains Fungi Level 4 Level 3 Level 2 Level 1 Decomposers Producer Primary consumer Secondary consumer Tertiary consumer Top carnivore Carnivore Herbivore Sun Bacteria

WHY IS EACH LEVEL OF THE ECOLOGICAL PYRAMID SMALLER THAN THE ONE BELOW IT? MORE ORGANISMS CAN EXIST HERE THAN HERE AND HERE ?

There is there loss of energy at each level of the food chain. To where is the energy lost? The cost of living! only this energy moves on to the next level in the food chain 17% Growth (biomass) 50% waste (feces) 33% cellular respiration energy lost to daily living

Feeding Levels How much energy can you get from food? –only the energy that is stored in the organism –80-90% energy lost from one level to next –food chain can only have 4 or 5 levels

Food Webs Food chains are linked together into food webs and overlap each other. Everything is connected! “Read” the arrow from the tail to the point as “is/are eaten by.” So, FISH  SQUID is read as “fish are eaten by squid” and PHYTOPLANKTON  KRILL is read as “phytoplankton are eaten by krill.” Would there be more fish or more phytoplankton in this ecological pyramid? PHYTOPLANKTON!

The SUN is the SOURCE! sun secondary consumers (carnivores) primary consumers (herbivores) producers (plants) loss of energy

THE ECOLOGICAL PYRAMID The amount of ENERGY AVAILABLE at each level DECREASES as you go up, so… There are fewer organisms at each level as you go up, or less “BIOMASS”

Vegetarians or Meat-eaters?? How many people can Earth support? –If we are meat eaters? –If we are vegetarian? more people can live on Earth fewer people can live on Earth

Example Grid-In Problem: A caterpillar consumes 100 kilocalories of energy. It uses 35 kilocalories for cellular respiration, and loses 50 kilocalories as waste (heat and in waste products). How much energy is allocated for growth (creation of new biomass)? Determine the trophic efficiency for its creation of new biomass.

But what about nutrients? Energy flows through the food chain and is LOST but NUTRIENTS CYCLE –nutrients must be RECYCLED to be available for the next generation –DECOMPOSERS return nutrients to the soil after creatures die fungi bacteria nutrientsnutrients decomposers

Nutrients cycle around… through decomposers soil producers consumers decomposers potassium nitrogen iron calcium phosphorus magnesium carbon

loss of energy sun secondary consumers (carnivores) primary consumers (herbivores) loss of energy producers (plants) decomposers Nutrients cycleEnergy flows soil

biosphere Ecosystem Inputs constant input of energy nutrients cycle nutrients can only cycle inputs  energy  nutrients inputs  energy  nutrients Don’t forget the laws of Physics! Matter cannot be created or destroyed energy flows through and is LOST

Carbon Abiotic Source: The atmosphere (CO2) Biotic Processes: Photosynthesis and Cellular Respiration and Decomposition

Oxygen Abiotic Source: The atmosphere (O2) Biotic Processes: Used in cellular respiration. Released in photosynthesis

Nitrogen Abiotic Source: Atmosphere (N2) Biotic Processes: Nitrogen-fixing bacteria enable plants to use N2; Released to environment by decomposition

Phosphorous Abiotic Source: Rocks (lithosphere); Released in weathering Biotic Processes: incorporated into food chains in the soil; Released by decomposition

Sulfur Abiotic Source: Rocks - Lithosphere Biotic Processes: Incorporated into food chains in the soil; Released by decomposition

Hydrogen Role: Major component of all biological molecules; Does not exist freely in nature Abiotic Source: Rocks – Hydrosphere (H2O Biotic Processes: Incorporated into food chains along with water, Released through decomposition/water release

CARBON DIOXIDE CYCLE INORGANIC COMPOUNDS CYCLE TOO!

WHAT LIMITS THE SIZE OF POPULATIONS ?

WHAT LIMITS THE SIZE OF POPULATIONS? LIMITING FACTORS COMPETITION CARRYING CAPACITY PREDATOR-PREY RELATIONSHIPS

LIMITING FACTORS (RESOURCES)! -temperature-food sources- -water supply-minerals-sunlight- If the requirements for an organism’s survival are not present, they cannot survive in that ecosystem.

COMPETITION ORGANISMS THAT EAT THE SAME FOOD SOURCE COMPETE WITH EACH OTHER FOR THAT FOOD SOURCE. Which organisms are competing with each other in this food web? LION & WOLF ELK, DEER & COW If the deer population decreases due to disease… What will happen to the grass population? What will happen to the lion and wolf populations? IN FOOD WEBS…AND ALL OF ECOLOGY…EVERYTHING IS CONNECTED TO EVERYTHING ELSE. A CHANGE IN ONE THING AFFECTS ALL! What will happen to the elk and cow populations? INCREASES DECREASE COMPLICATED! Will they increase b/c they have more grass to eat or will they decrease b/c the lions will eat more elk and the wolves will eat more cows? A CHANGE IN ONE POPULATION AFFECTED ALL OF THE POPULATIONS IN THE FOOD WEB!

The PURPLE LINE shows how a population (# of organisms) fluctuates with a constant carrying capacity. At each PEAK, organisms have overproduced (ie. made too many babies) and the ecosystem cannot support them. Many die off and the population declines. At each DIP, the ecosystem can support more organisms, so the population begins to overproduce again, resulting in the next PEAK. Overall, the poulation is in DYNAMIC EQUILIBRIUM. CARRYING CAPACITY! The BLUE LINE shows “carrying capacity” or the number of organisms that the ecosystem can support. It remains constant.

PREDATOR PREY RELATIONSHIPS The PREDATORS then begin to die off because their food source is declining, at which point the PREY population increases because fewer of them are being eaten and more of them can reproduce…AND THE CYCLE STARTS ALL OVER AGAIN! When the PREY population increases, the PREDATOR population also increases, but there is a LAG because it actually takes time for the PREDATOR population to make new organisms. As the PREDATORS increase, the PREY population decreases, because there are more PREDATORS eating them! THE PREDATOR AND PREY ARE IN DYNAMIC EQUILIBRIUM!

ECOLOGICAL SUCCESSION VIEW THE VIDEO ON THE NEXT PAGE OR AT THE VIDEO GOES FAST, SO HIT THE PAUSE/PLAY BUTTON IF YOU NEED TO SLOW IT DOWN…OR PLAY IT MORE THAN ONCE… GO TO THE NEXT SLIDE TO SEE THE MOVIE MORE DETAILS ABOUT ECOLOGICAL SUCCESSION CAN BE FOUND IN YOUR REVIEW BOOK!