THE BIOSPHERE Ch. 3 p.62-83

What is Ecology? Study of interactions between organisms and between organisms and their environment. Ernst Haeckel – coined term Ecology in 1866 Greek word “oikos” means house Natures “houses”come in many sizes

Levels of Organization Ecologist study organisms ranging from the various levels of organization: Species Population Community Ecosystem Biome Biosphere

Species Group of similar organisms that can breed and produce fertile offspring Organism

Population group of organisms, all of the same species, which interbreed and live in the same area. Population

Community an assemblage of different populations that live together

Ecosystem Collection of organisms that live in a place with the nonliving environment Ecosystem

Biome Group of ecosystems with the same climate and dominant commuties Tropical rain forest Tropical dry forest Tropical savanna Temperate woodland and shrubland Desert Temperate grassland Boreal forest (Taiga) Northwestern coniferous forest Temperate forest Mountains and ice caps Tundra Ecosystem

Ecosystem Biosphere The part of the earth where life exists including land, water, air, and atmosphere

Three Ecological Methods of Study Observing What species live here? How many individuals of species are there? Experimenting Used to test a hypothesis Ex - making artificial environments in the lab Modeling Making models to gain insight into complex phenomena Ex. - Global warming

Autotrophs vs. Heterotrophs Autotrophs – make their own food so they are called PRODUCERS Heterotrophs – get their food from another source so they are called CONSUMERS

Two Main forms of Energy for Autotrophs Sunlight The main source of energy for life on earth Photosynthesis Chemical Some organisms such as bacteria, rely on the energy stored in inorganic compounds Chemosynthesis

Detritivores and Decomposers Feeds on plant and animal remains Types of Consumers Omnivores Eat plants and meat Herbivores- only eat plants Carnivores - only eat meat Detritivores and Decomposers Feeds on plant and animal remains

How does Energy flow through an Ecosystem? Energy flows through an ecosystem in ONE direction, sun or chemicals Autotrophs heterotrophs

Energy Flow in Ecosystems:

Feeding Relationships Food Chain – steps of organisms transferring energy by eating & being eaten Food Web – network of all the food chains in an ecosystem

Food Web

Ecological Pyramids Trophic Level – each step in a food chain or food web Biomass Pyramid Energy Pyramid Pyramid of Numbers

Pyramid of Numbers -relative number of individuals at each trophic level

Pyramid of Biomass - amount of potential food available for each trophic level

Pyramid of Energy - amount of energy available at each trophic level Only 10% of the energy from each trophic level is passed on to the next level Most of the energy is used by the organisms for life processes Some of the energy is lost as heat

How does Matter move through an ecosystem? Unlike the one way flow of energy, matter is recycled within & between ecosystems Nutrients are passed between organisms & the environment through biogeochemical cycles Biogeochemical Cycles: Bio –life Geo – Earth Chemo – chemical WATER CYCLE NUTRIENT CYCLES: CARBON CYCLE NITROGEN CYCLE PHOSPHORUS CYCLE

Why are nutrients important ? Every living organism needs nutrients to build tissues and carry out essential life functions. 95% of your body is made of… OXYGEN CARBON HYDROGEN NITROGEN

Availibility of nutrients If a nutrient is in short supply, it will limit an organisms growth. It is called a limiting nutrient When a limiting nutrient is dumped into a lake or pond, an algal bloom occurs and can disrupt the ecosystem

THE WATER CYCLE

CARBON CYCLE (see fig.3-13) 4 PROCESSES MOVE CARBON THROUGH ITS CYCLE: Biological Geochemical Mixed biochemical Human Activity CO2 CO2

NITROGEN CYCLE (see fig.3-14) in Atmosphere Nitrogen-containing nutrients in the biosphere include: Ammonia (NH3) Nitrate (NO3-) Nitrite (NO2-) ORGANISMS NEED NITROGEN TO MAKE AMINO ACIDS FOR BUILDING PROTEINS!!! N03- & N02- NH3

PHOSPHORUS CYCLE (see fig.3-15) PHOSPHORUS FORMS PART OF IMPORTANT LIFE-SUSTAINING MOLECULES (ex. DNA & RNA)