The Biosphere Chapter 3  Objectives  Distinguish between the biotic and a biotic factors in the environment.  Compare the different levels of biological organization  Explain the difference between niche and habitat.

What is Ecology?  Ecology is a scientific study of interactions among organisms and between organisms and their environment

Biosphere  Biosphere- part of the earth that supports life.  Combined portions of the planet in which all of life exists, including land, water and air or atmosphere  Extends from 8 kilometers above Earth’s surface to 11 kilometers below the surface of the ocean

What shapes an ecosystem?  Abiotic Factors  physical, or nonliving factors that affect organisms  bullfrog affected by availability of water and temperature of air

What shapes an ecosystem?  Biotic and Abiotic Factors  Biotic Factors  living things that affect an organism  biotic factors affecting bullfrog: plants it eats, birds that might eat it, other species that compete for food or space

Interactions and Interdependence  Interactions within the biosphere produce a web of interdependence between organisms and the environment in which they live

Biotic and Abiotic Factors Biotic Factors ECOSYSTEM Abiotic Factors

Levels of Organization  Individual or Organism: interactions between an organism and its surroundings  cottontail rabbit  Population: groups of Organism that belong to the same species and live in the same area  group of cottontail rabbits

Levels of Organization  Communities: different populations that live together in a defined area  rabbits, coyotes, ravens, lizard  Ecosystem: collection of all the organisms that live in a particular place, together with their nonliving, or physical, environment  rabbits, coyotes, ravens, lizard, rocks, dirt, climate, water

Levels of Organization  Biome: group of ecosystems that have the same climate and dominant communities  desert, tundra, tropical rain forest  Biosphere: planet Earth

Where animal live Habitat Habitat a place where an organism lives out its life. It includes both biotic and abiotic factors. Niche is all strategies and adaptations a species uses in its environment.

Niche  An organism’s niche includes:  Place in food web  Range of temperatures organism needs to survive  Type of food it eats  How it obtains food  Other species that use it as food  Physical conditions necessary for survival  When and how it reproduces

Niche  Two species cannot share the same niche in the same habitat.  Different species can occupy similar niches.  Ex - three species of warblers live in the same spruce trees but feed at different elevations and in different part of the trees

Warbler Niches Bay-Breasted Warbler Feeds in the middle part of the tree Cape May Warbler Feeds at the tips of branches near the top of the tree Spruce tree

 If you were to turn over a log in the woods you would see centipedes, worm, ants and millipedes.  They all look similar and they have similar niches.  But they all feed on different things.  Centipede eats beetles  Worms eat organic material  Ants eat dead insects  Millipedes eat decaying leaves

Symbiosis  When two species live close together.  Three types:  Parasitism – one is harmed (host), one benefits (parasite)  Mutualism – both benefit  Commensalism – one is neutral, one benefits

Mutualism Parasitism Commensalism

Homework  Pg 45  1-5  Read 2.2

Nutrition and Energy Flow 2.2  Objectives  Compare how organism satisfy their nutritional needs  Trace the path of energy and matter in an ecosystem  Analyze how matter is cycled in the abiotic and biotic parts of a biosphere

Producers  Autotrophs an organism that uses light energy or energy stored in chemical form to make energy rich compounds–  “self feed”  Use sunlight to create carbohydrates via photosynthesis  Ex – Plants, algae and some bacteria

Producers

Consumers  Heterotroph organism that cannot make their own food and feeds on others.  Must eat to obtain energy.  Ex – animals, fungi, some protists

Types of Heterotrophs  Herbivore – eats plants  Carnivore – eats animals  Omnivore – eats plants and animals  Scavengers – eats plant and animal remains  Ex- snails, crabs, earthworms, vultures  Decomposer – breaks down organic matter  Ex – bacteria and fungi

Feeding Relationships  Energy flows through an ecosystem in one direction,  from the sun or inorganic compounds  autotrophs (producers)  various heterotrophs (consumers).

Food Chain  Food Chain is a simple model that shows how energy and matter move throughout an ecosystem.  A series of steps in which organisms transfer energy by eating and being eaten.  i.e. Wheat  mouse  snake  hawk

Food Chain Example

Food Web  Food wed a model that showed all the possible feeding relationships at each trophic level.  Network of complex interactions formed by the feeding relationship among the various organisms in an ecosystem.

Trophic Levels  Trophic Levels each step in a food chain or food web  1 st level = producers  2 nd, 3 rd, or higher levels = consumers  Usually no more than 5 levels because 90% of energy is lost at each level.

Ecological Pyramid  A diagram that shows the relative amounts of energy or matter contained within each trophic level in a food chain or food web.  Energy, biomass, and population numbers can all be represented by a pyramid.

Ecological Pyramid

Cycles of Matter  Recycling in the Biosphere  Matter is recycled within and between ecosystems.  Matter moves through an ecosystem in biogeochemical cycles.

Water Cycle

Carbon Cycle

Nitrogen Cycle N 2 in Atmosphere NH 3 NO 3 - and NO 2 -

Nitrogen Cycle  78% of Earth’s atmosphere is Nitrogen gas = N 2  Nitrogen containing products:  Ammonia (NH 3 )  Nitrate ions (NO 3 -)  Nitrite ions (NO 2 -)  Nitrogen is needed for protein and nucleic acid synthesis

Nitrogen Cycle  Converting nitrogen gas into ammonia is called nitrogen fixation.  Only certain types of bacteria can do this.  Plants use the converted products (NH 3, NO 3 -,& NO 2 -) to make plant proteins.  Some bacteria convert nitrates into nitrogen gas (denitrification).

Phosphorus Cycle

 Phosphorus is important for the formation of DNA and RNA molecules.  Phosphorus is not very common and does not enter the atmosphere, instead it is found mostly on land in rock and soil.

Primary Productivity  The rate at which producers create organic matter.  Determines the size of the community.  Limited by availability of nutrients.  Land – phosphorus (P), nitrogen (N), potassium (K)  Marine – nitrogen  Fresh water - phosphorus

Algal Bloom

Interactions and Interdependence  Interactions within the biosphere produce a web of interdependence between organisms and the environment in which they live

Energy Flow  Energy flows from the sun or inorganic compounds to producers.  Consumers eat producers to get energy.  The primary source of energy on Earth is the sun!!