ecology- background

Ecology- backgroundUnit 2

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I. Ecology

A. Ecology: study of relationships among living organisms and interactions organisms have with the environmentB. Ecologists observe, experiment, and model using a variety of tools and methods.

II. The Biosphere

A. Biosphere: a thin layer around the earth

1. Extends several kilometers above earths surface

2. Extends several kilometers below Earth’s surface

II. The Biosphere

III. Biotic and Abiotic factors

A. Biotic factor1. Living factors in an organism’s environment

B. Abiotic Factor1. Nonliving factors in an organism’s

environment

Subatomic particlesAtomMoleculeOrganelleCell

Unicellular organisms

TissueOrgans

Organ systemsOrganism/Species

Multicellular organisms

PopulationCommunityEcosystemBiomeBiosphere

IV. Levels of Organization

V. Ecosystem Interactions

A. Habitat1. Area where an organism lives

B. Niche1. The role or position an organism has in its

environment.

VI. Community Interactions

A. Competition1. More than one organism uses a resource at

the same timeB. Predation

1. Get food/energy by eating other organisms.

VII. Symbiotic Relationships

A. Symbiotic Relationships 1. Close relationship that exists when two or

more species live together

2. Mutualism i. both benefit

3. Commensalismi. one benefits; other no harm or benefit

4. Parasitism 1. host is killed

In what type of activity would you most expect an ecologist to be involved?A. identifying and classifying various

species of insects in an ecosystemB. locating fossils of distinct species of

turtles in a geographical areaC. observing the relationships that

woodpeckers have with other species in their environment

D. studying the internal organs of a seal to learn how it survives in its environment

Answer: C

Which are biotic factors in a forest environment?A. plants and microscopic organisms

living in the soilB. pH and salt concentration of the soilC. sunlight, soil type and soil nutrientsD. temperature, air currents and

rainfall

Answer: A

The act of one organism consuming another organism for food is _______.A. predationB. ParasitismC. CommensalismD. Mutualism

Answer: A

Certain types of tropical orchids use trees for support in order to grow higher and obtain more light. This neither harms nor benefits the tree. What type of symbiotic relationship is this?

A. CommensalismB. CompetitionC. MutualismD. Parasitism

Answer: A

What is the name for a group of interacting populations that occupy the same area at the same time?A. EcosystemB. HabitatC. Biological communityD. Biotic collection

Answer: C

Section 2.3 Cycling of Matter

A. Energy is transformed into usable forms to support the functions of an ecosystem.

B. The cycling of nutrients 1. Matter in living organisms2. Physical processes found in the environment like weathering

I. Cycles in the Biosphere

II. Biogeochemical cycles

A. The exchange of matter through the biosphere

B. Bio= lifeC. Geo= earthD. Chemical= chemistry

III. The Water Cycle

III. Water Cycle

A. About 90% of water vapor evaporates from oceans, lakes, and rivers

B. About 10% evaporates from the surface of plants through transpiration.

C. Freshwater 1. Constitutes about 3% of all water on Earth2. About 69% of all freshwater found in ice

caps and glaciers

IV. Carbon and Oxygen Cycles

IV. Carbon and Oxygen Cycles

A. Carbon and oxygen often make up molecules essential for life

B. Carbon and oxygen recycle relatively quickly through living organisms

V. Terms of Cycles

A. Long-term Cycle1. Organic matter converted to peat, coal, oil,

or gas deposits (carbon)2. Calcium carbonate (carbon and oxygen)

B. Sort-term Cycle1. Burning fossil fuels (carbon)

I. The Nitrogen Cycle

A. Nitrogen Fixation1. Capture and conversionof nitrogen into a useable form by plants

I. Nitrogen Cycle Cont.

A. Nitrogen enters food web when plants absorb nitrogen compounds from soil.

B. Consumers get nitrogen by eating plants or animals that contain nitrogen.

C. Nitrogen is returned to the soil in several ways

1. Animals urinate2. Organisms die3. Organisms convert ammonia into nitrogen

compounds4. denitrification

II. The Phosphorous Cycle

II. Phosphorus Cycle Cont.

A. Short-term Cycle1. Phosphorus is cycled from the soil to

producers and then from the producers to consumers.

B. Long-term Cycle1. Weathering or erosion of rocks that contain

phosphorus slowly adds phosphorus to the cycle.

Terrestrial BiomesSection 3.2

I. Terrestrial Biomes

A. Biomes:1. Classified by their plants, temperature, and precipitation

B. Climate:1. Average weather conditions in an area

i. Includes temperature and precipitation

Tropical Rainforest

Coniferous Forest

Taiga… permafrost

Tundra

I. Ecological Succession

A. The change in an ecosystem that happens when one community replaces another.

i. Result of changing abiotic and biotic factorsB. Two types of ecological successions

i. Primary successionii. Secondary succession

http://www.youtube.com/watch?v=AWwe0udewD8

II. Primary Succession

A. The establishment of a community in an area of exposed rock that does not have any topsoil

III. Secondary succession

A. Orderly and predictable change that takes place after a community of organisms has been removed but soil remains intact

I. Population Dynamics

A. Species might not be able to expand its population range

1. Cannot survive abiotic conditions found in expanded region

II. Population Limiting Factors

A. There are two categories of limiting factors

1. Density-independent factors2. Density-dependent factors.

IV. Density-Dependent Factors

A. Any factor in the environment that depends on the number of members in a population per unit area

1. Biotic factors2. Disease3. Competition4. Parasites

III. Density-Independent Factors

A. Any factor in the environment that does not depend on the number of members in a population per unit area

1. Weather events2. Fire3. Human alterations of the landscape4. Air, land, and water pollution

V. Population Growth Rate

A. Population dynamics (changes)1. Based on

i. Natality (birth rate)ii. Mortality (death rate)iii. Emigration (out)iv. Immigration (in)

I. Population Density

A. Population Density1. The number of organisms per unit area

B. Spatial Distribution1. Dispersion is the pattern of spacing of a

population.

II. Population Growth Rate

A. The population growth rate (PGR)1. Explains how fast a given population grows

B. Population dynamics (changes)1. Based on…

i. Natality (birth rate) (+)ii. Mortality (death rate) (-)iii. Emigration (out) (-)iv. Immigration (in) (+)

III. Exponential Growth Rate

A. Occurs when…growth rate is proportional to the size of the population

B. All populations grow exponentially until…some limiting factor slows the population’s growth

IV. Logistic Growth Model

A. The population’s growth slows or stops following exponential growth, at the population’s carrying capacity

V. Carrying Capacity

A. Maximum number of individuals in a species that an environment can support for the long term

B. Limited by energy, water, oxygen, and nutrients available

Preserving Biodiversity

I. What is biodiversity?

A. The variety of life in an area1. Determined by the number of different

species in that area.B. Biodiversity increases

1. Stability of an ecosystem2. Contributes to health of biosphere

C. Types of Biodiversity1. Species Diversity2. Ecosystem Diversity

II. Diversity

A. Species Diversity1. Number of different species and relative abundance of each species in a biological community

B. Ecosystem Diversity1. Variety of ecosystems present in the

biosphere

III. The Importance of BiodiversityA. Most of the world’s food crops come from just a few species

B. Wild species serve as reservoirs of desirable genetic traits that might be needed to improve domestic crop species.

IV. Factors that Threaten BiodiversityA. Current high rate of extinction

1. Due to the activities of a single species—Homo sapiens

i. Changing conditions on Earth faster than new traits can evolve to cope with the new conditions

• Overexploitation• Habitat loss• Destruction of habitat• Disruption of habitat• Fragmentation of habitat• Pollution

• Acid precipitation• Eutrophication• Introduced (non-native)

species• Natural Resources

• Renewable• Nonrenewable

V. Factors Influencing Biodiversity

VI. Threats

A. Overexploitation:1. excessive use of a resource for economic

valueB.Habitat loss:

1. Elimination or alteration of a habitati. Destructionii. Disruption

C. Fragmentation of the habitat:A. Separation of an ecosystem into smaller

parts; unnaturally confines populations

VI. Threats cont.

A. Pollution:1. Changes the chemical composition of soil ,

air or water (pH, additional chemicals)B. Introduces species (non-native)

1. Either intentionally or unintentionally introduces/transported into a new habitat; out-compete or are predators of natural species.

VII. Protecting Biodiversity

A. About 7% of world’s land is set aside as some type of reserve

B. The United Nations supports a system of Biosphere Reserves and World Heritage sites