13.1 ecologists study relationships ecology - study of the interactions between living things and...

13.1 Ecologists Study Relationships

Ecology - study of the interactions between living things and their surroundings.


Levels of Organization

• Biosphere• Ecosystem• Community• Population• Organism


Biosphere

• The portion of earth that supports life

• Extends from the lower atmosphere to the bottom of oceans

• Supports diverse array of organisms and wide range of climates


OrganismOrganism

Population

Population

Community

Community

Ecosystem

Ecosystem

• An ecosystem/biome - all of the living and nonliving things in a given area (climate, soil, water, rocks).


Earth has six major biomes.


Community• All the different species that live in the same

place at the same time.• Example

– Forest communityFlowers, bushes, trees, snakes, frogs, birds, squirrels,

deer, etc…


Population• A group of one species, which interbreed and live

in the same place at the same time.• Example

– Population of bullfrogs in Jackson Bog


OrganismOrganism

• An organism - individual living thing, ex: alligator.


Why does the Earth have Deserts?

• http://www.youtube.com/watch?v=T6Us1sPXBfA&list=PLElB7nLNHZvhSor-RW0mv1FE_IDi9ZuiA&index=6


KEY CONCEPT Every ecosystem includes both living and nonliving factors.

13.2 Biotic and Abiotic Factors


• Abiotic factors are nonliving things. – moisture– temperature– wind– sunlight – Soil

• Not constant (always changing) moisture

sunlight



Biotic Factors

• Living components of the environment



keystone


• A keystone species is a species that has an unusually large effect on its ecosystem.


• Indicator species provide a sign of an ecosystem’s health.

– amphibians– top predators

16.3 Water Quality13.2 Biotic and Abiotic Factors


Producers provide energy for other organisms in an ecosystem.

• autotrophs - make their own food.

13.3 Energy in Ecosystems


Almost all producers obtain energy from sunlight.

• Photosynthesis• Chemosynthesis – produce energy from chemicals

carbon dioxide + water +hydrogen sulfide + oxygen

sugar + sulfuric acid



Measuring productivity

• Gross primary productivity – rate at which producers capture E

• Biomass – organic material in an ecosystem– Only E stored as biomass is available to other

organisms in the ecosystem



Consumers are organisms that get their energy by eating other living or once-living resources.

• heterotrophs



• Herbivores – eat producers• Carnivores – eat other consumers• Omnivores – eat both producers and

consumers• Detritivores – feed on the “garbage” of an

ecosystem



A food chain is a model that shows a single chain of consumers within an ecosystem.

DESERT COTTONTAILGRAMA GRASS HARRIS’S HAWK

13.4 Food Chains and Food Webs

• arrows point in the direction that energy flows


A food web - interrelated food chains in an ecosystem



Fly Factory turns Waste into Food

• http://www.youtube.com/watch?v=ak0pOxhGDqM&list=UUzWQYUVCpZqtN93H8RR44Qw&index=6


Energy Flow

moves from producers to consumersTrophic level – indicates the organism’s position in the

sequence of energy transfers• Producers – 1st trophic level• Herbivores – 2nd trophic level• Predators of herbivores – 3rd trophic level



Quantity of Energy Transfers

10% of the total E consumed in one trophic level is incorporated into the organism in the next level

• E is used to maintain body T, to move, etc.• E is lost when organisms escape being eaten

– decomposer return their E to the lower trophic levels• E is lost in parts of the organism that can not be broken down

by the predator – bones, teeth, hair



energy transferredenergy

lost

An energy pyramid shows the distribution of energy among trophic levels.

•Higher trophic levels contain less energy • support fewer individuals



Biomagnification - accumulation of toxins in the food chain.

• Pollutants move up the food chain.– predators eat contaminated

prey

• Top consumers (humans) are most affected.

• DDT- Birds of prey

16.3 Water Quality13.4 Food Chains and Food Webs


Species Interactions

Predation• Predator – captures, kills, and consumes prey

– Influences where and how species live by determining their relationship in the food web

– Regulates population size

Natural selection favors adaptations that improve the efficiency of predators at finding, capturing, and consuming prey

Natural selection favors adaptations for prey to avoid, escape, or otherwise ward off predators


13.1 Ecologists Study Relationships13.4 Food Chains and Food Webs


Natural selection of plants has favored adaptations that protect them from being eaten

• Thorns, sticky hairs, tough leaves• Chemical defenses (secondary

compounds)– Strychnine, nicotine, poison ivy– May also have medicinal uses –

codeine, morphine



Parasitism – one individual is harmed (host) while the other benefits (parasite)

• Does not usually result in the immediate death of the host



Ectoparasite – external parasites – do not enter hosts body• Ticks, fleas, lice, leeches, mosquitoes

Endoparasite – internal parasite – live inside host• Disease causing bacteria, protists, tapeworm

Affect the health and reproduction of the host

Stimulates evolution of defenses in hosts• Tough skin & chemically defended openings

– eyes-tears– mouth-saliva– nose-mucus



Natural selection favors adaptations that allow a parasite to efficiently attack host

• Specialized anatomically – Mouth parts

• and Physiologically– Body chemistry to survive different environments etc.



The Most Horrifying Parasites!

• http://www.youtube.com/watch?v=ulK9XUd_hh8


Competition

• The use of a limited resource by 2 or more species• Types

– Intraspecific- competition between organisms of the same species

– Interspecific- competition between 2 or more different species of organisms



Competitive Exclusion

• one species is eliminated from a community • Natural selection favors differences between potential

competitors – character displacement



Resource Partitioning• Organisms “divide” resources• Adaptations allow for use of resources in different

ways or at different times• Examples

– Diurnal vs. Nocturnal



Mutualism

Cooperative relationship in which both species benefit• Some relationships are so close that neither species can

survive without the other• Ex: pollination



Symbiosis: A Surprising Tale of Species Cooperation

• http://www.youtube.com/watch?v=2AM3ARs9MMg&list=PLJicmE8fK0Ehrg3meytY7DT8LJiwuU3Th&index=170


Commensalism

• Interaction in which one species benefits and the other is not affected



Niche -Role of a species in its environment (Job)

Types:– Fundamental- ideal; absence of competition– Realized- natural; competition and other

constraints

14.1 Habitat and Niche


Generalist vs. Specialist

• Broad niche

• Tolerate variety of resources and conditions

• Example– raccoons

• Narrow niche• Very specific

adaptations• Example

– Koalas



A habitat is all aspects of the area in which an organism lives.

– biotic factors– abiotic factors


13.1 ecologists study relationships ecology - study of the interactions between living things and...

Documents

jackson bog slide

nonliving factors

wide range of climates

keystone species

different species

nonliving things

ecosystems health

moisture sunlight