Biology: Chapter 2- Principles of Ecology Section 1: Organisms and their Environment

Sharing the World  How much do you know about the environment and the organisms that share your life?  Humans moving into territories occupied by fields and wildlife.  You interact with many different organisms DAILY!  What affects their environment affects YOU!

Studying Nature  Some ordinary people can identify every animal, plant and rock they pass.  Others keep records of average rainfall and temperature.  Others still study plants and animals and how they grow and live.  This proves that the environment around us is successful or not.

What is Ecology?  Ecology - the study of interactions that take place between organisms and their environment.  Must use Qualitative and Quantitative data.  Qualitative- through observation of organisms  Quantitative- through taking measurements and carrying out experiments in the field/lab.  Ecological research includes the fields of:  Mathematics  Chemistry  Physics  Geology  Branches of Biology

The Biosphere  Biosphere - is the portion of Earth that supports living things.  Spans from the high atmosphere to the deepest depths of the ocean.  Think if the earth was the size of an apple, the biosphere would be represented by the peel.  Although it is thin, it supports a diverse group of organisms and a wide range of climates.  Living things are affected by both the physical/nonliving environment and by other living things.

The Nonliving Environment  Abiotic factors - the nonliving parts of an organism’s environment.  Air currents  Temperature  Moisture  Light  Soil

 Abiotic factors have obvious effects on living things and often determine which species survive in a particular environment.  To study a particular organism, you must study ALL the abiotic factors. The Nonliving Environment

The Living Environment  Biotic factors : all the living organisms that inhabit an environment.  REMEMBER!!! Living organisms affect other living organisms.  All organisms depend on others directly or indirectly for food, shelter, reproduction, or protection.

Levels of Organization  Ecologists study individual organisms, interactions among organisms of the same species, and interactions among organisms of different species.  For easy studying, there are different levels of organization:  Organism by itself  Populations  Communities  Ecosystems

Interactions within Populations  Population : is a group of organisms, all of the same species, which interbreed and live in the same area at the same time.  Sharing resources in their environment is important  How far individuals are apart  Competition for food, water, mates, and other resources  Adaptations that reduce competition  Tadpole vs. Frog  Caterpillar vs. Butterfly

Interactions within Communities  No species lives independently!!!  Biological community : made up of interacting populations in a certain area at a certain time.  Several different populations  A change in one population in a community may cause changes in the other populations.  Ex. Fluctuations in population numbers

Biotic and Abiotic Factors form Ecosystems  Ecosystem : made up of interacting populations in a biological community and the community’s abiotic factors.  Ecologists also study interactions between separate populations and their physical surroundings.  Because animals and plants in an area can change, and because abiotic factors can change, ecosystems are subject to change.

Ecosystems  Two major kinds:  Terrestrial  Aquatic

Ecosystems: Terrestrial  Ecosystems on land  Ex. Forests, meadows, and rotting logs

Ecosystems: Aquatic  Occur in both freshwater and saltwater  Freshwater: ponds, lakes, streams  Saltwater: (marine ecosystems) make up approximately 70% of Earth’s surface.

Organisms in Ecosystems  Habitat : the place where an organism lives out its life.  Habitats can change and disappear  Why do you think this happens?

Organisms in Ecosystems  Niche : all strategies and adaptations a species uses in its environment; all the interactions with the biotic and abiotic parts of its habitat.  how it meets its specific needs for food and shelter  How and where it survives  Where it reproduces

Survival Relationships  Mutualism  Symbiotic relationship where both organisms benefit  Commensalism  Symbiotic relationship in which one species benefits and the other is neither harmed nor benefited  Parasitism  Symbiotic relationship in which a member of one species derives benefit at the expense of another species

 Mutualism  Ants and acacia tree  Commensalism  Spanish moss on a tree  Clownfish and a sea anemone  Parasitism  Tick  Leech  Brown-headed cowbirds Survival Relationships

Biology: Chapter 2- Principles of Ecology Section 2: Nutrition and Energy Flow

Question  How do organisms obtain energy?  Please take a few minutes to answer this by yourself and answer on your notes sheet.

Producers  Autotrophs : an organism that uses light energy or energy stored in chemical compounds to make energy-rich compounds  Ex : PLANTS!!!!  YOU are not an autotroph!!!  THE SUN is not an autotroph!!!

Consumers  Heterotroph : an organism that cannot make its own food and feeds on other organisms  Ex : YOU!!!  Grasshoppers  Cows  Rabbits  Wolves, etc.

Consumer Types  Herbivores  ONLY feeds on plants  Rabbits, grasshoppers, beavers, squirrel, bees, elephants, fruit-eating bats, etc.  NOT HUMANS!!!  Carnivores  Heterotrophs that eat other heterotrophs  Lions, tigers, etc.  Scavengers  Organisms that do no kill for food; eat animals that are already dead.  Black vultures, wolves, etc.

Consumer Types  Omnivore : organisms that eat a variety of plant and animal materials  Ex. : humans, raccoons, opossums, bears

Decomposers  Organisms that break down and release nutrients from dead organisms  Break down the complex compounds of dead and decaying plants and animals into simpler molecules that can be more easily absorbed.  Ex. : Fungi, protozoan, and bacteria  QUESTION: What would the world look like if there were no decomposers??

Flow of Energy  Food Chain vs. Food Web  Trophic Level : feeding steps that represent the passage of energy and material  Biomass : total weight of living material at each trophic level  Energy pyramids  Energy  Numbers  Biomass

Cycles in Nature  Sun is the ultimate and primary source of all energy.  Matter is in the form of nutrients that moves through all organisms.  Finite amounts of matter; recycled in different cycles because matter is NEVER lost!  Water Cycle  Carbon Cycle  Nitrogen Cycle  Phosphorus Cycle