IV - Ecology, Ecosystems, & Food Webs Flashcards
Characteristics of Life
Composed of CELLS Contain DNA Capture & transform MATTER & ENERGY GROWTH, SURVIVAL & REPRODUCTION HOMEOSTASIS EVOLUTION
Levels of organization in ecology includes
Organism population Community Ecosystem Biosphere
Organism
any form of life
Species
groups of organisms that RESEMBLE each other, &, in cases of SEXUALLY REPRODUCING organisms, can potentially interbreed
How many species exist/ are discovered??
estimates of 5 to 100 million species, most are insects &
microorganisms; so far only about 1.8 million named;
Wild/native species
population that exists in its natural habitat
Domesticated/ introduced species
population
introduced by humans
Population
group of interacting INDIVIDUALS of the
SAME species
Population examples
sunfish in a pond, white oak trees in a
forest, people in a city
Habitat
place where a population usually lives
Genetic diversity
in natural populations individuals VARY in their genetic makeup
Community
populations of all species living together in a given area
Community examples
redwood forest community, consisting of
populations of redwoods & other trees, shrubs &
herbaceous species, animals, & microorganisms.
Biological community
complex interacting
network of plants, animals, & microorganisms.
Ecosystem
community of different species
interacting with one another (*biotic) & with their non–
living (**abiotic) environment of matter & energy
Ecosystem examples
a patch of woods, a lake or pond, a farm field, an entire
watershed in a tropical rain forest.
Biotic factors
Living components/ biota
Abiotic factors
Non-living components
Biotic factors example
plants,
animals, & microorganisms
Abiotic factors examples
water,
air, nutrients, & solar energy
Biome
large regions characterized by a distinct climate &
specific life–forms, especially vegetation, adapted to the
region.
Major biomes include
temperate grassland, temperate
deciduous forest, desert, tropical rain forest, tropical
deciduous forest, tropical savannah, coniferous forest,
tundra
Aquatic life zone
major marine or freshwater areas
containing numerous ecosystems.
Major aquatic life zones include
akes, streams, estuaries,
coastlines, coral reefs, & the deep ocean
Ecosphere/biosphere
all of Earth’s ecosystems
together
What Sustains Life?
Energy from Sun
Cycling of matter
Gravity
Energy from Sun
one–way flow of usable energy from sun, through
feeding interactions, to low–quality forms (heat)
Cycling of matter
the continual flow of matter between the nonliving
environment & living organisms;
Gravity
enables Earth to hold its atmosphere; causes
downward movement of matter in nutrient cycles
The ultimate source of energy in most ecosystems is …
the sun
Incoming solar radiation goes to …
Heating of atmosphere & earth's surface Evaporating water Generating wind Photosynthesis Reflected by clouds, dusts, surface
Outgoing radiation consists of
Reflected incoming radiation
Degraded heat
Nutrient cycles include
Carbon Phosphorus Nitrogen Water Oxygen
Nutrient
any atom, ion, or molecule an organism
needs to live, grow, or reproduce
Macronutrients
needed in relatively large amounts
Macronutrients examples
C, O, H, N, P, S, K, Ca, Mg, Fe
Micronutrients
needed in relatively small amounts
Micronutrients examples
Na, Zn, Cu, Cl, I
Nutrient cycles
involve
continual flow of nutrients from nonliving (air, water,
soil, rock) to living organisms (biota) & back again.
All nutrient cycles are driven by
Solar radiation
gravity
Closed System
a system in which energy, but not
matter, is exchanged between the system & its environment.
Closed System example
Earth -> minimal matter lost
Energy freely flow
Open System
a system in which both energy & matter
are exchanged between the system & its environment.
Open System example
Organisms
Earth major components
Lithosphere
Hydrosphere
Atmosphere
Biosphere
Earth made up of
Crust
Mantle
Core
Living organisms fall into two main categories
producers/autotrophs
consumers/ heterotrophs
Producers
make their own food from compounds obtained in the
environment.
Producers includes
Plants
Bacteria
Green plants make food through
Photosynthesis
Bacterias make food through
Chemosynthesis
Consumers
get their energy & nutrients by feeding on other organisms
or their remains.
Consumers includes
herbivores, carnivores, decomposers, etc.
Photosynthesis
complex chemical reaction in plants, in which solar radiation is captured by chlorophyll (& other pigments) &
used to combine carbon dioxide & water to produce carbohydrates
(e.g., glucose), other organic compounds, & oxygen.
Photosynthesis equation
carbon dioxide water + solar energy -> glucose + oxygen
aerobic respiration
complex process that occurs in the cells
of organisms, in which organic molecules (e.g., glucose) are
combined with oxygen to produce carbon dioxide, water, & energy.
aerobic respiration equation
glucose + oxygen -> carbon dioxide + water + energy
Major kinds of consumers
Primary Secondary Tertiary Omnivores scavengers Decomposers Detritivores
Primary consumers
(=herbivores) feed directly on producers
Secondary consumers
=carnivores) feed on primary
consumers
Tertiary consumers
feed only on carnivores
Omnivores
consumers that feed on both plants & animals
Scavenger
feed on dead organisms
Decomposers
consumers that complete the breakdown &
recycling of organic materials from the remains & wastes of other
organisms
Detritivores
feed on detritus (partially decomposed organic
matter, such as leaf litter & animal dung)
Detritus feeders includes
Long-horned beetle
Bark beetle
Carpenter ant
Termite & carpenter ant
Decomposers includes
Dry rot fungus
Mushroom
Limiting factor
an environmental factor that is more important
than other factors in regulating survival, growth, or reproduction.
Law of tolerance
the existence, abundance, & distribution of a
species in an ecosystem is determined by whether the levels of
one or more physical or chemical factors fall within the range
tolerated by that species.
Limiting factor principle
too much or too little of any abiotic
factor can limit or prevent growth of a population, even if all
other factors are at or near the optimum range of tolerance
The survival, growth, & reproduction of organisms is
determined, in part, by
maximum & minimum tolerance
food chains
Sequence of organisms, each of which is the food for the next
First trophic level
Producers
Plants
Second trophic level
Primary consumers
Herbivores
Third trophic level
Secondary consumers
Carnivores
Fourth trophic level
Tertiary consumers
carnivores
In nature, ecological efficiency varies from 5% to 20% energy available between successive trophic levels (95% to 80% loss).
About 10%
efficiency is a
general rule
Silver Springs, FL Energy Flow
Producers
20810 Cal/sq. meter/ yr
Silver Springs, FL Energy Flow
Herbivores
3368 Cal/sq. meter/ yr
Silver Springs, FL Energy Flow
Carnivores
383 Cal/sq. meter/ yr
Silver Springs, FL Energy Flow
Top carnivores
21 Cal/sq. meter/ yr
Silver Springs, FL Energy Flow
Decomposers
5060 Cal/sq. meter/ yr
Biomass Pyramids
commonly measured as dry weight per
square meter for each trophic level, can either MIRROR the
energy pyramid or be INVERTED
Biomass pyramids mirroring energy pyramid example
abandoned field
Biomass pyramids inverting energy pyramid example
ocean
Inverted biomass pyramids result because
producers are eaten by consumers.
Pyramids of Numbers
depend upon both the size of organisms & the biomass pyramid.
Pyramids of Numbers mirroring energy pyramid example
Grassland
Pyramids of Numbers inverting energy pyramid example
Temperate Forest
Why is temperate forest inverted?
forests have smaller numbers of large
producers than do grassland
Gross primary productivity
rate at which
an ecosystem’s producers convert solar energy into
chemical energy as biomass
Net primary productivity
rate at which
energy for use by consumers is stored in new biomass.
NNP can be calculated by …
GPP - [rate at which producers use biomass]
Estimated annual net primary productivity of major biomes & aquatic life zones
Estuaries Swamps & marshes Tropical rain forest ... Tundra Desert Scrub Extreme desert
Estimated annual contribution of the various types of
biomes & aquatic life zones to Earth’s overall net primary productivity
Open ocean Tropical forest Temperate forest ... Lakes & streams Tundra Extreme desert
Ecosystem services
natural benefits that support life on
the earth & are essential to the quality of human life &
the functioning of the world’s economies.
Ecosystem services examples
- control & moderate climate
- recycle vital nutrients
- provide energy & mineral resources
- furnish food, fiber, medicine, timber, & paper
- pollinate crops & useful native plants
- absorb, dilute, or detoxify pollutants
- control populations of pests & disease organisms
- slow soil erosion & prevent flooding
- provide biodiversity of genes & species
Why is biodiversity an important ecosystem
service?
The rich variety of organisms provides material benefits
(food, raw materials, energy, & medicine), ecosystem
services (purification of air & water, natural pest
control…), & aesthetic benefits.
What are two principles of ecosystem
sustainability?
Almost all natural ecosystems achieve sustainability by
1) using renewable solar energy as the energy source; &
2) recycling nutrients needed for survival, growth, &
reproduction.
Ecologists learn about ecosystems through a combination
of methods:
field research
systems analysis
Systems analysis includes
- system measurement
- data analysis
- systems modeling
- systems simulation
- systems optimization
New technologies enables scientists to
collect field
information more effectively across broad geographic scales.
New technologies example
Remote sensing
Geographic Information Systems
Remote sensing involves
use of
sensors to collect information about a
system from a distance.
GIS provide
the computer
technology for organizing, storing,
and analyzing complex map data
