Download Principles of Ecology

Principles of Ecology
 What is ecology?
 The study of the interactions between organisms
and the living and nonliving components of their
environment
 Involves collecting information about organisms and
their environment
 Issues dealing with Ecology
 Thinning ozone layer
 Climate changes (greenhouse effect)
Levels of Organization
 Biosphere
 The thin volume of earth and its atmosphere that supports life
 All organisms are found within the biosphere
 Biome- group of ecosystems that have same climate and
similar dominant communities
 Ecosystem
 Includes all of the organisms and the non living environment
found in a particular place
 Ex. Ponds, bottom of shoe, deep oceans, rain forests
 Community
 All the interacting organisms living in an area
 Ex. All the fish, turtles, plants, algae, and bacteria in a pond
 Population
 Includes all the members of a species that live in one place at one
time
 Species
 Group of organisms that breed and produce fertile organisms
Producers
 What is the main energy source for life on Earth?
 What are producers?
 Organisms that capture energy and use it to make food
 Also known as autotrophs
 Examples
 Photosynthesis-light energy is used to power chemical
reactions
 CO₂ and H₂O are converted into O₂ and sugars
 Plants, algae, cyanobacteria
 Chemosynthesis-convert energy from chemical bonds within
inorganic molecules into chemical energy
 Use hydrogen sulfide and convert it into carbohydrates
 Bacteria
 Volcanic vents on deep ocean floors, hot springs, tidal marshes
Types of Consumers
 Heterotroph- organisms that rely on other
organisms for their energy and food supply
 Consumer
 Many types of heterotrophs
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Herbivores eat only plants
Carnivores eat animals
Omnivores eat both plants and animals
Detritivores eat plant and animal remains, and
other dead organic matter
 Decomposers break down organic matter
 Decomposers are essential for autotrophs to obtain
their necessary nutrients
Feeding Relationships
 What happens to the energy in an ecosystem?
 Flows through ecosystem in one direction
 Starts with sun to various consumers
 Food chain- steps showing the transfer of energy
from organism to organism
 Starts with producer, tertiary consumer
 Welcome to Discovery Education Player
 Food web- network of complex interactions,
linking all food chains in an ecosystem together
Trophic Levels
 Each step in food chain or food
web=trophic
 Ecological pyramids- shows the
relative amount of energy
available at each trophic level
 Organisms use about 10% of this
energy for life processes, rest is
lost as heat
 Respiration, movement,
reproduction
 Most ecosystems contain only
3 or 4 trophic levels
 First level-Producers
 Second level-Herbivore
 Third level-Predators
 Biomass- total amount of living
tissue w/in given trophic level
 All organisms need energy to carry out essential
functions
 Ex. Growth, movement, maintenance, repair and
reproduction
 The amount of energy an ecosystem receives and
the amount that is transferred from organism to
organism has an important effect on the
ecosystem’s structure
Sec 3- Cycles of Matter
 95% of body made up of 4 elements
 Matter is recycled within and between
ecosystems
 Biogeochemical cycles- the passing of
elements, compounds and other forms of
matter from one organism to another
 Each substance travels through a
biogeochemical cycle-moving from the abiotic
portion of the environment, such as the
atmosphere, into living things and back again
Water Cycle and Nutrient
Cycles
 4 important processes of the water cycle
 Evaporation, transpiration, condensation, precipitation
 The amount of water the atmosphere can hold
depends on temperature and air pressure
 Nutrient cycles- every organism needs nutrients
 Build tissues, carry out essential life function
 Carbon, nitrogen, phosphorus, oxygen
 The basis of the carbon cycle is photosynthesis
and cellular respiration
 Plants use carbon dioxide
 3 major sources of CO2-cellular respiration, combustion,
and decomposition of organic matter
Nitrogen Cycle
 Nitrogen is essential for organisms to make
proteins and nucleic acids
 Makes up 78% of atmosphere
 Plants can only use nitrate
 Nitrogen fixation is the process of converting
nitrogen gas to nitrate (ammonia)
 How does this happen?
 Bacteria
 Live in soil or in the roots of plants
 Denitrification- nitrates converted into nitrogen gas
Phosphorus Cycle
 Forms part of DNA and RNA
 Not found in atmosphere, found mostly in
rock and soil minerals, ocean sediments
 Most exist in form of inorganic phosphate
 Land-plants-consumers
Ch 4- Ecosystems and
Communities
 Habitat is where an organism lives
 Includes abiotic and biotic factors
 Biotic factors include all living things that affect the organism
 Ex. Animals, plants, algae, fungi, bacteria
 Abiotic factors are nonliving factors which are the physical
and chemical characteristics of the environment
 Ex. Temperature, humidity, pH, salinity, oxygen
concentration, amount of sunlight, availability of nitrogen
in the soil affects how fast plants can grow
 Biotic and abiotic determine the survival and growth of
an organism, productivity of the ecosystem in which
organism lives
Niche
 What is a niche?
 It is a species way of life, or the role the species plays in its
environment
 Includes the range of conditions that the species can tolerate
 The methods by which it obtains needed resources
 The number of offspring it has
 Its time of reproduction
 All of its other interactions with its environment
 Difference between fundamental and realized
 Range of conditions can potentially tolerate and use
 Range of resources it actually uses
Community Ecology
 YouTube - Species' five interactions - Ecology
 5 major types of close interactions can powerfully affect
an ecosystem
 Predation, parasitism, competition, mutualism, and
commensalism
 Competition- occurs when organisms of the same or
different species attempt to use a resource in same place at
same time
 Predation- interaction where one organism captures and
feeds on another organism
 Predator- the one doing the killing and eating
 Prey- the one that gets dominated
 Symbiosis- any relationship where 2 species are living
closely together
 3 types- mutualism, commensalism, parasitism
Types of Symbiotic
Relationships
 Mutualism- relationship where both
species benefits
 Commensalism- relationship where one
specie benefits and others is not helped
or harmed
 Parasitism- relationship where one
organism lives on or inside other
organism and harms it
 Write down which relationship is being
shown
 Lions and zebras
 Honey bee pollinates flower
 Remora fish attaches itself to other shark
and eats the food that is dropped by
shark
 Lions and cheetahs
 Mosquito bites humans
Ecological Succession
 Ecosystems are constantly changing in response to natural
and human disturbances, as ecosystem changes, older
inhabitants gradually die out and new organism move in,
causing further changes in community
 These predictable changes that occurs in community over time=
ecological succession
 Primary succession- succession that occurs on surface
where no soil exists
 Volcanic eruption builds new island
 Pioneer species
 Secondary succession- succession that occurs after natural
events or human activities, after disturbance community
interactions restore the ecosystem
 Wildfires
Sec 3- Biomes
 What is a biome?
 Very large terrestrial ecosystems that contain number of smaller
but related ecosystems within them, have characteristic climate
and species
 How many different biomes cover the Earth’s land surface?
 10
 Each is defined by unique set of abiotic factors-climate, and
by characteristic set of plants and animals
 Tundra, taiga, temperate forest, northwestern coniferous
forest, temperate woodland and shrubland, tropical rain forest,
tropical dry forest, temperate grassland, tropical savanna, and
desert
 Tundra is cold and treeless
 Covers 1/5 of world’s land surface
 Very little precipitation, short growing seasons, animals include
caribou, musk oxen, snowy owls, arctic foxes, snowshoe hares
 Permafrost
 Northern N America, Asia, Europe
 Taiga- covered with dense evergreen
forests
 Plants are adapted for long and cold winters,
short summers and poor soil
 Animals include moose, bears, wolves and lynxmany hibernate for 6-8 months
 North America, Asia, northern Europe
 Temperate forests-trees loose their leaves,
pronounced seasons, precipitation evenly
distributed, cold winters/warm summers
 Trees include cottonwood, maple
 Animals include deer, foxes, raccoons
 Eastern U.S., most of Europe, China
 Temperate Grasslands- contain grasses, low
rainfall, fertile soil, support herds of mammals,
turned into farmland
 Warm to hot summers/cold winters
 North America, central Europe
 Deserts- receive less than 25 cm of rainfall a year,
cold at night, vegetation is sparse, animals include
foxes, lizards and snakes
 Africa, Middle East, Australia
 Savannas- tropical and subtropical grasslands with
scattered trees and shrubs
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Herbivores-zebras, giraffes, and gazelles
Carnivores-lions, leopards, and cheetahs
Climate-Two seasons- wet and dry
Eastern Africa, southern Brazil
 Tropical Rain forest-tall trees, year round
growing seasons, abundant rainfall, highest
species richness
 Animal life very diverse-birds, monkeys, snakes,
lizards
 Insects very abundant
 Contains 1/5 of world’s known species
 2 football fields may have 300 species
 Southeast Asia, southern India, parts of Central and
South America
 Tropical Dry forest- precipitation is seasonal
rather than year-round
 Generally warm year-round, rich soils
 Tigers, elephants
 Parts of Africa, Mexico, India
 Temperate Woodland and Shrublandsemiarid climate, dominated by shrubs
and open woodlands
 Coyotes, foxes, blacktailed deer
 Hot, dry summers, cool moist winters
 Western coasts of N and S America
 Northwestern Coniferous forest- made up
of variety of conifers, lush vegetation
 Mild temperatures, cool summers with
abundant precipitation during spring, winter,
fall
 Pacific coast of northwestern U.S. and
Canada
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Tundra
Taiga
Savanna
Deciduous Forest
Rainforest
Grasslands
Desert
www.blueplanetbiomes.org/world_biomes.htm
Aquatic Ecosystems
 Determined by primarily the depth, flow, temperature,
and chemistry of the overlying water
 Grouped by abiotic factors that affect them
 Freshwater ecosystems divided into 2 types- flowing
water and standing water ecosystem
 Plankton- tiny, free-floating organisms live in
freshwater and saltwater
 Phytoplankton- unicellular algae supported by
nutrients, form base of food web
 Zooplankton- planktonic animals that feed on
phytoplankton
 Freshwater wetlands- water covering land for at least
part of year
 Bogs, marshes, swamps
 Estuaries
 Estuary occurs where freshwater rivers and streams
flow into the sea
 Ex. Bays, mud flats, salt marshes, Mangrove
swamps
 Very species rich
 Vital to marine animals that are used as food
 Ex. Shrimp, mullet, redfish, anchovies
 Marine Ecosystems
 Divided into photic and aphotic zones
 Ocean divided into zones based on depth, distance
from shore: intertidal zone, coastal ocean, open ocean