ECOLOGY

What is Ecology?  Study of interactions between organisms and their environment. Ernst Haeckel – coined term Ecology in 1866 Greek word “oikos” means house Why does this make sense?

Three Ecological Methods of Study 1.Observing What species live here?What species live here? How many individuals of species are there?How many individuals of species are there? 2.Experimenting Used to test a hypothesisUsed to test a hypothesis Ex - making artificial environments in the labEx - making artificial environments in the lab 3.Modeling Making models to gain insight into complex phenomenaMaking models to gain insight into complex phenomena Ex. - Global warmingEx. - Global warming

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

Living vs. Nonliving Parts of the Environment  BIOTIC – This term describes the living parts of the environment (animals, plants, fungi, bacteria, protists, etc.)  ABIOTIC – This term describes the nonliving parts of the environment (air, water, rocks, soil, light, etc.)

Levels of Organization  Ecologists study several different levels of organization:  Species  Population  Community  Ecosystem  Biome  Biosphere

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

Population  group of organisms, all of the same species, which interbreed and live in the same area. Population A population of bullfrogs in a pond

Community Community Community  an assemblage of different populations that live together

Ecosystem Ecosystem  Community of organisms (biotic) that live in a place with the nonliving environment (abiotic)

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

Habitat and Niche  Habitat – where an animal lives out its life  Niche – the role or position a species has in its environment. Kind of like its JOB!  A species usually occupies a niche different from those of other species.  What is a polar bear’s habitat? Its niche?

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

Types of Consumers Herbivores- only eat plantsCarnivores - only eat animals Omnivores- eat plants AND animals 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 (notice the direction of the arrows!!)

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

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  Most of the energy is used by the organisms for life processes  Some of the energy is lost as heat  Only 10% of the energy from each trophic level is passed on to the next level 100% 10% 1% 0.1%

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 1. 1.WATER CYCLE 2. 2.NUTRIENT CYCLES: a)CARBON CYCLE b)NITROGEN CYCLE c)PHOSPHORUS CYCLE

Why are nutrients important ? 95% of your body is made of… 1) 1)OXYGEN 2) 2)CARBON 3) 3)HYDROGEN 4) 4)NITROGEN   Every living organism needs nutrients to build tissues and carry out essential life functions.

Availibility of nutrients   If a nutrient is in short supply, it will limit an organisms growth. It is called a limiting nutrient.   When a 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: 1)Biological 2)Geochemical 3)Mixed biochemical 4)Human Activity CO 2

NITROGEN CYCLE (see fig.3-14) Nitrogen-containing nutrients in the biosphere include: 1)Ammonia (NH3) 2)Nitrate (NO3-) 3)Nitrite (NO2-) ORGANISMS NEED NITROGEN TO MAKE AMINO ACIDS FOR BUILDING PROTEINS!!! N 2 in Atmosphere NH 3 N0 3- & N0 2 -

 Nitrogen fixation – turning unusable nitrogen gas (N2) into useable nitrate, nitrite, or ammonia  How does it happen? Lightning (atmospheric nitrogen fixation) or Bacteria (bacterial nitrogen fixation)  Denitrification – the reverse process. Turning useable nitrate, nitrite, or ammonia back into nitrogen gas!

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