Download Levels of Ecological Study

Introduction To Ecology
Ch. 50
Introduction To Ecology
– the scientific study of the
interactions between organisms and their
environments
 Ecology determines both the distribution and
abundance of organisms
 Distribution and abundance depends on abiotic
(non-living factors such as temperature, light,
water, nutrients, pH, etc.) and biotic (living
factors such as all the living organisms)
components of the environment
 Ecology
Levels of Ecological Study
1.
Organismal Ecology – morphological,
physiological, and behavioral way in which
individual organisms meet the challenges
posed by their abiotic and biotic
environments
Levels of Ecological Study
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A population is a group of individuals of the
same species living in a particular geographic
area
Population Ecology –
factors that affect how
many individuals of a
particular species live in
an area
Levels of Ecological Study
3.
A community consists of all the organisms of
all the species that inhabit a particular area; it
is an assemblage of populations of many
different species
Community Ecology – the whole array of
interacting species
in a community
(includes predation,
competition, and
disease)
Levels of Ecological Study
4.
An ecosystem consists of all the abiotic
factors in addition to the entire community of
a species that exist in a certain area; may
consist of many different communities
Ecosystem Ecology – the
emphasis in on the energy flow
and the cycling of chemicals
among the various biotic and
abiotic components
Levels of Ecological Study
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The Biosphere is the global ecosystem, the
layer of Earth inhabited by life; the sum of all
the plant’s ecosystems
Factors Affecting Distribution
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Biogeography – the study of the past and present
distribution of individual species
In studying the dispersal of organisms, ecologists
work through a series of logical steps to
determine what limits geographical distributions
Factors Affecting Distribution
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Of course, we do not want to purposely
introduce organisms to areas where they
do not already exist
Examples – African Honeybee
(purposely) and Zebra Mussel
(accidentally)
Tens Rule – one out of ten introduced
species becomes established, and one
out of ten established species become
common enough to become pests.
Factors Affecting Distribution
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Behavior and habitat selection

Habitat selection by ovipositing insects,
which often choose only certain host
plants, may limit their distribution
Biotic Factors

The inability to survive and reproduce may
be due to predation, disease, or
competition
Abiotic Factors

Temperature, water, sunlight, wind, and
rocks and soil
Factors Affecting Distribution
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Temperature and moisture are the major
climatic factors determining distribution
Climate is the prevailing weather conditions
of a locality and are influenced by
temperature, water,
light, and wind
Biomes are major
types of ecosystems
found in broad
geographic regions
Solar Radiation and Latitude
What Causes Seasons?
Lake Stratification and
Seasonal Turnover
Aquatic Biomes
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Freshwater biomes – less than 1% salt
concentration
Marine biomes – average of 3% salt
concentration
Oceans influence global rainfall, climate, and
wind patterns
Marine algae and photosynthetic bacteria
produce a large portion of the world’s oxygen
and consume enormous amounts of carbon
dioxide
Aquatic Biomes
Freshwater Biomes
Freshwater Biomes
A Eutrophic Lake
An Oligotrophic Lake
A River
Freshwater Biomes
Wetlands – areas covered with water and
supporting hydrophytes (water plants); range
from marshes to swamps to bogs
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These richly diverse biomes are important to
flood control and water quality
Freshwater Biomes
Estuaries – where a freshwater river or
stream meets the ocean; often bordered by
wetlands called mudflats and saltmarshes
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Serve as feeding and breeding areas for marine
invertebrates, fish, and waterfowl
Marine Biomes
Marine Biomes
Intertidal zones – the daily cycle of tides
exposes the shoreline to variations in water,
nutrients, and temperature, and to the
mechanical force of wave action
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Rocky intertidal zones have
organisms adapted to firmly
attach to the hard substrate
Sand or mudflat intertidal zones
are home to burrowing worms,
clams, and crustaceans
Marine Biomes
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Coral reefs – found in
tropical waters in the
nertic zone; are highly
diverse and productive
biomes
Coral reefs are easily
damaged by pollution,
development, native
and introduced
predators, and high
water temperatures
Marine Biomes
Benthos – nutrients reach the benthic zone
as detritus falling from the waters above.
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Nertic benthic communities receive sunlight and
are very diverse and productive
Various invertebrates and fishes that are adapted
to cold, dark, and high water pressure inhabit the
abyssal zone
Chemoautotrophic
prokaryotes are adapted
to the hot, low-oxygen
environment surrounding
deep-sea hydrothermal
vents
Terrestrial Biomes
Terrestrial Biomes
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The geographic distribution of the world’s
major terrestrial biomes is related to abiotic
factors – in particular, the prevailing climate
Biomes are usually named for their
predominant vegetation and major climatic
features
Each bio also has characteristics
microorganisms, fungi, and animals
Tropical Forests
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Occur within 23° latitude of the equator
Variation in rainfall result in tropical dry
forests, tropical deciduous forests, and
tropical rain forests, where rainfall is
abundant
Savanna
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Tropical and subtropical grassland with
scattered trees and rainy and dry seasons
Fires and large grazing mammals restrict
vegetation to grasses and small broad-leaved
plants
Deserts
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Characterized by low and unpredictable
precipitation
May be hot or cold depending on location
Desert animals have physiological and
behavioral adaptations to dry conditions
Plants may use
CAM photosynthesis
and have water
storage adaptations
and protective spines
and poisons
Chaparral
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Common along coastlines in midlatitudes that
have mild, rainy winters and hot, dry
summers
The dominant vegetation – dense, spiny
evergreen shrubs – is maintained by and
adapted to periodic fires
Temperate Grasslands
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Maintained by fire, seasonal drought, and
grazing by large mammals
Soils are deep and rich in nutrients
Temperate Deciduous Forests
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Characterized by broad-leaved deciduous
trees
Grow in midlatitude regions that have
adequate moisture to support the growth of
large trees
Trees drop
their leaves
before winter
Coniferous Forest (Taiga)
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A large biome found in northern latitudes
Characterized by harsh winters with heavy
snowfall
Coniferous trees grow in dense, uniform
stands
Coastal
temperate rain
forests area
also coniferous
forests
Tundra
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The northernmost limit of plant growth
Characterized by dwarfed or mat-like
vegetation
The alpine tundra, found at all latitudes on
high mountains above the tree line, has
similar flora and fauna
The artic tundra has a shallow root layer due
to permafrost,
permanently
frozen soil