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Basic EcologyJohn Herron
The Nature Conservancy – Texas Chapter
(paste over photo with an appropriate image)
conserve
The Nature Conservancy
lands and waters
The mission of
is to
the
on which
depends.
Biodiversity and The Nature Conservancy
all life
TNC Conservation Tools
Land acquisition
Conservation
easements
Demonstration projects
Prescribed fire
Habitat restoration
Species surveys
Ecology - defined
The study of Nature that deals with inter-
relationships, or the dependence of all living
things on all other living things and their
surroundings.
The study of the relationships of organisms to
their environment and to one another. (Brewer
1994)
The word ecology derives from the Greek words
oikos, which means “house,” and logos, which
means “discussion or study.”
Ecology
The study of living systems
– Aquatic ecology
– Forest ecology
– Field ecology
– Experimental ecology
– Population ecology
– Community ecology
– Behavorial ecology
„Ecology‟ Encompasses…
Physical environment
Organisms – species, populations, communities, ecosystems
Inter-relationships
– Predator-prey; consumers
– Competition
Nature is dynamic
– Change, flows, cycles, adaptation, selection, evolution.
– Balance
Includes humans
Understand the 7 Principles of Ecology
1. The plan or producer, the grazing animal or consumer and
the intrinsic value of a healthy ecosystem needs to be looked
at together, not separately.
2. The natural resource manager should understand the change
and know it has an influence on all of his management
decisions.
3. For every action on the land there are multiple reactions.
4. Nature abhors a void and provides plants through the
process of primary and secondary succession to fill the
openess.
5. Humans have found that nature knows best. Organisms
which are suited and adapted to change occupy the site.
6. Everything must go somewhere.
7. There is no such thing as a free lunch.
• Landscape Structure and Function
• Biotic Diversity
• Species Flow
• Nutrient Redistribution
• Energy Flow
• Landscape Change
• Landscape Stability
• Biotic Diversity
Sandor, M. 2004.
http://quizlet.com/2659795/7-principles-in-landscape-ecology-flash-cards/
Seven Principles of Landscape Ecology
Laws of Ecology
• All things are interconnected
• Everything goes somewhere
• There‟s no such thing as a free lunch
• Nature bats last
Callenbach, E. 2008. Ecology: A pocket guide.
Environment = Physical Factors
• Sun
– Weather/Climate
– Wind
– Currents
– Temperature/Heat
• Moon - Tides
• Water
• Minerals/Soils
= „Abiotic‟
Natural Selection
• Evolution – species change over
time
• Natural selections works at the
individual level
• Individuals vary
• Individuals with desirable traits
survive better
• If those traits are inheritable, they
are passed on to descendents
• As a result, those populations
changes
Population - A group of organisms of the
same species occupying a particular space at
a particular time
Population Dynamics
Population growth– Immigration
– Emigration
– Mortality
– Reproduction
Growth rate
Density
Carrying capacity
Dispersion and Movement
CARRYING CAPACITY - The maximum number of
individuals of a given species that a habitat
can sustain indefinitely.
Communities
Populations of different species occupying a
certain area (i.e. plants, birds, fish, insects,
etc.)
Plants
Cricket GrasshopperField Mouse
ScorpionToadPraying
Mantis
Red Shouldered
Hawk
Coachwhip MockingbirdWhiptail
Food Chain
Mockingbird
Plants
Cricket GrasshopperField Mouse
ScorpionToadPraying
Mantis
Red Shouldered
Hawk
Coachwhip Whiptail
Food Web
Elements of a food web on a native
grassland.Sun
Red-tailed hawk
Wolf
FoxJackrabbit
Bison
Decomposers
Mouse
Grass
GrasshopperPrairie chicken
P 1,500,000
H 200,000
C1 90,000
C2=1
Grassland (Summer)
(Individuals per 0.1 hectare)
General pattern in nature: there are many more plants than
herbivores, greater numbers of herbivores than carnivores, seldom
more than a few top carnivores.
Pyramid of Numbers
The relationship between prairie-to-forest
succession and grouse species.
Prairie
chicken
Sharp-tailed
grouse
Ruffed
grouse
Spruce
grouse
Ecosystems
• An ecosystem consists of organisms from
many different species living together in a
region that are connected by the flow of
energy, nutrients, and matter that occurs as
the organisms of different species interact
with one another.• (Microsoft® Encarta® Encyclopedia 2002)
• Is a self-sustaining system involving the
interaction of living and nonliving
elements in a manner which sustains life.
"…game can be restored by the creative
use of the same tools which have
heretofore destroyed it - ax, plow, cow,
fire, and gun."
Aldo Leopold, Game Management, 1933.
Ecosystem management
Ecological Restoration
- Restore natural processes
- Prescribed burning
- Selective mowing
- Managed grazing
- Seasonal water flows
When we contemplate the whole globe as one great dewdrop, striped and dotted with continents and islands, flying through space with all other stars all singing and shining together as one, the whole universe appears as an infinite storm of beauty.
John Muir (1838-1914)Founder, Sierra Club
Biological Diversity
The variety of life forms: the different plants,
animals and microorganisms, the genes they
contain, and the ecosystems they form. It is
usually considered at three levels: genetic
diversity, species diversity and ecosystem
diversity.
Kinds of Biodiversity
Species
– Species numbers
– Species richness
– Taxonomic diversity
Genetic
Habitat/Eco-systems
Species Diversity
Mammals – 4,000
Birds – 9,040
Amphibians – 4,184
Reptiles – 6,300
Fish – 19, 056
Plants – 248,428
Insects – 751,000
Texas Biodiversity
Mammals Birds Herps Fish Total % Total
Nongame 122 509 178 157 966 81%
Game 20 47 1 30 98 8%
T & E 20 28 33 26 107 9%
Extinct 6 6 1 8 21 2%
TOTAL 168 590 213 221 1192 100%
TX Only 10 49 44 23 126 11%
Relative Biodiversity
Univ. of Sydney
http://bugs.bio.usyd.edu.a
u/Entomology/importance
/imagePages/speciesSca
pe.html
Species-scape
Univ. of Sydney http://bugs.bio.usyd.edu.au/Entomology/importance/imagePages/speciesScape.html
Figure 27. Texas
Environmental Resource
Stewards (TERS): Texas
Ecological Assessment
Protocol (TEAP) Results Pilot
Project. U.S. EPA. 2005
Major Terrestrial Biomes of the World
• Ice
• Tundra
• Taiga
• Grassland
• Temperate Forest
• Chaparral
• Savanna
• Desert
• Mountain
• Tropical Rainforest
Texas Birds and their
Habitat
Above Canopy Species
Vultures Hawks Swallows
Swifts
Canopy
Owls Woodpeckers Vireos Thrushes
Nuthatches Tanagers Warblers
Creepers
Midstory
Warblers Jays Vireos
Chickadees Cardinals Kinglets
Understory
Mockingbirds Bluebirds
Wrens Doves
CanopyJunipers Hickories
Pines Oaks
Cedars Elms
Maples Pecans
MidstoryAsh
Maples
Sweetgum
Hackberries
UnderstoryTall ShrubsLow ShrubsDogwoods Agaritas
Viburnums Yaupons
Hawthorns Wax Myrtles
Ground CoverPrairie WetlandGramas Sedges
Bluestems Rushes
Paspalums Cattails
Ground CoverSparrows ShorebirdsWaterfowl Wadingbirds
Island Biogeography
Size of island &
Distance between islands
Determines
»Species diversity
»Extinction rates
»Immigration/Emigration ability
Applies to virtual islands!!! (habitat fragments)
McArthur and Wilson (1967)
Biodiversity and Habitat Fragments
• Island biogeography applies to terrestrial habitat
„islands‟ too!
• Small habitats hold fewer species, smaller
populations
• Small populations are vulnerable to extinction
due to:
– environmental changes
– natural disasters
– random chance
Habitat Fragmentation
When habitat is divided
into smaller sections
Some species benefit,
others are harmed
•Increased edge effect
•Increasing generalists
•Increased parasitism
•Increased predation
•Specialists lost
•“Ecological trap”
FRAGMENTATION AND EDGE EFFECT
Edge Effects on Wildlife
May benefit– White-tailed deer
– Some game birds
– Small mammals
– Predators
– Invader Species
May harm– Interior forest
species
– Grassland species
– Habitat specialists
– Threatened or endangered species
Corridors
• To allow interspersal among islands and
fragments
• Width is important
• Corridor must be appropriate habitat type
• Results still somewhat theoretical
Threats to Biodiversity
• Human population effects– Habitat loss
– Habitat fragmentation
– Incompatible development
• Climate change
• Invasive/Exotic species
• Disruption of ecosystem function– Overgrazing
– Fire suppression
– Diminished freshwater flows
• Limited understanding of natural systems
Management Implications
Conserve all habitat/eco-system types
Conserve „all the pieces‟
Promote plant diversity
Promote native species
Realize genetic diversity is also important
Re-establish natural processes (flood, fire, buffers)
Consider edge effects
Interdependence ----------- Sustainability
“There are some who can live without wild things, and some who cannot. ... Like winds and sunsets, wild things were taken for granted until progress began to do away with them. …
…Now we face the question whether a still higher „standard of living‟ is worth its cost in things natural, wild, and free. For us of the minority, the opportunity to see geese is more important than television, and the chance to find a pasque-flower is a right as inalienable as free speech.”
Aldo Leopold
1887 - 1948
It Ain‟t Easy Being Green
…When green is all there is to be
It could make you wonder why, but why wonder why?
Wonder,
I am green and it'll do fine, it's beautiful!
And I think it's what I want to be.
Joe Rapposo, 1970
(Oh, and Kermit the Frog, too)
The Nature Conservancy
The Nature
Conservancy's efforts to
preserve the diversity of
life on Earth depends
solely on the support of
its members.
nature.org/texas
www.facebook.com/natureconservancyte
xas