Download Lecture 2: Wildlife Ecological Principles and Population Ecology Part 1

Realm
Biome
Ecosystem
ECOLOGY
Population
Organism
Organ
Tissue
Taxonomy
Anatomy
Physiology
Genetics
Cell
Organelles
Molecules
Atoms
Biochemistry
Genomics
Molecular Biology
More complex,
Larger
Less Abundant
Community
REALM
BIOME
ECOREGION
LANDSCAPE
ECOSYSTEM
COMMUNITY
POPULATION/SPECIES
GENETIC
Realms = large regions
with ecosystems share a
broadly similar biota.
Mostly terrestrial and
freshwater oriented
Oceanic
Antartic
Australasian
Nearctic
Paleartic
Afrotropic
Indo-malay
Biome (region of similar vegetation)
 Biomes are the major regional groupings of plants and
animals discernible at a global scale. Their distribution
patterns are strongly correlated with regional climate
patterns and identified according to the climax
vegetation type. However, a biome is composed not
only of the climax vegetation, but also of associated
successional communities, persistent subclimax
communities, fauna, and soils.
Biomes are determined by precipitation and
temperature
2.4 Biomes and climate
867 Global Terrestrial Ecoregions
Kentucky’s Major Recognized (Physiographic) Ecoregions
Ecosystem
 Ecosystem = biological community + abiotic environment
(the non-living things such as geology, water). Typically
ecosystem is used to describe things at large scales.
 There are many examples of ecosystems -- a pond, a forest,
an estuary, a grassland and their boundaries are not fixed
in any objective way, although sometimes they might seem
obvious.
 Often have complex food (trophic) webs and “self-
contained” nutrient cycles such as nitrogen cycle
Ecosystems
Energy flow
Nutrient cycles
Absorption
Plant
By
Remains
Plants
N cycle
Bacteria
Bacteria
Nitrates
Bacteria
Ammonia
Free N
In
Atmosphere
Bacteria
Chihuahuan
Desert
Ecosystem
(example)
Ecological Community
 A community is an assemblage of plant and animal
populations that live in a particular area or habitat. The
combinations of species within that community make it
unique in the way it looks (composition and structure) and
function (the ecological work it does).
Community Properties
 Scale
 Spatial and Temporal Structure
 Species Diversity (Biodiversity)
 Trophic structure
 Succession and Disturbance
Scale
 Size of community – water droplet to rotting log to
forest floor
Community scale dictated by the measurer/definer
Spatial Structure
 Horizontal – Uniform, random, clumped
 Vertical – underground, forest floor, herb layer, shrub layer,
mid-story, canopy
canopy
Mid-story
Shrub
Forest floor
Below ground
Herb
14,000 ft
Vertical Community
Spatial Structuring
South Facing
Slopes
12,000 ft
North Facing
Slopes
Alpine Zone
Alpine tundra
Subapline Zone
Spruce-fir Forest
10,000 ft
8,000 ft
Foothills Zone
Pinyon-Juniper
Sagebrush
Woodland
6,000 ft
Upper Montane
Zone – Mixed
Conifer Forest
Lower Montane
Zone – Ponderosa
Pine Forest
Vertical Community
Spatial Structuring
Alpine Zone
Alpine tundra
Subapline Zone
Spruce-fir Forest
Upper Montane
Zone – Mixed
Conifer Forest
Foothills Zone Pinyon-Juniper
Sagebrush Woodland
Lower Montane
Zone – Ponderosa
Pine Forest
Temporal Structure
 Phenology = timing of appearance and
activity of species (e.g. spring
wildflower blooming period)
Species
ECOSYSTEM
COMMUNITY
POPULATION/SPECIES
Population- is local occurrence of
individuals of the same species; typically
the unit of management used to maintain
viability in natural patterns, abundances, and
distributions. Species are defined as
individuals that look identical or very
similar and interbreed under natural
conditions.
E.g. Cheetahs of
Serengeti National Park,
Tanzania, Africa
Species Diversity (Biodiversity)
 Species richness = # of species (simplest measure of
biodiversity)
 Biodiversity Indices = # of species and their relative
abundance within the community
 E.g. you count 100 birds in two forest blocks



Block A has 95 starlings, 2 cardinals, 1 house wren, 1 blue jay,
and 1 Carolina chickadee (a total of 5 species)
Block B has 50 starlings, 20 cardinals, 10 house wrens, 5 blue
jays, and 5 Carolina chickadees (a total of 5 species, but the
individuals are more evenly distributed among species;
therefore Block B would be considered more biodiverse)
Trophic (feeding) levels
 Primary Producers (plants, phytoplankton,
some bacteria – can make their own food –
autotroph – self feeding)
 Heterotrophs – utilize autotrophs or others to
obtain energy
 Primary Consumers (eat primary producers –
herbivores – zooplankton, insects, rabbits,
elephant)
 Secondary Consumer (carnivore – eat animals
(called prey) microscopic predators to lions,
tigers)
 Tertiary Consumer (shark, bass, kingsnake)
 Decomposers (bacteria, fungi;break down
small bits of organic material and often
recycle it back into soil, air, water)
Omnivore – eats both plants and
animals
Herbivore – eats plants only
Carnivore – generally solely a meat
eater, or of the Order Carnivora
Scavengers – (technically
carnivores) eat dead animals
Parasites – obtain nutrition from by
living inside or on another organism
Ecological Succession
 Ecological Succession: predictable change in species
over time as new set of species modifies the
environment to enable the establishment of another
set of species. Each recognizable “step” in process is
known as a seral stage.
Disturbance
Increasing
Ecological
Complexity and
Stability
Examples of Disturbance = Flood, Fire, Wind, Herbivory, Timber Harvesting, Mining,
Road Building, Urbanization, Agriculture
Succession Types
 Primary Succession – sequence of species (sere or seral
stage) on landforms not influenced by a community,
example, rock or retreating glacier
 Secondary Succession – vegetation partially or
completed removed but seeds, seedlings, spores, etc.
remain
 Climax community – self-perpetuating, mature
community that is resistant to change and dominated
by species that can tolerate competition – “final stage”
Thinking About Succession Patterns and Processes
 Early in succession, species are
generally excellent dispersers
and tolerate harsh
environments, but not the best
inter-specific (between
species) competitors.
 As ecological succession
progresses, these are replaced
with species which are better
competitors, (but not as good
at dispersing and more
specialized to deal with the
microenvironments created by
other species likely to be
present with them).
 Early species modify their
environment in such a way as
to make it possible for the next
round of species. These, in
turn, make their own
replacement by superior
competitors possible.
Wildlife Habitat
 Wildlife Habitat - Place where organism lives
 Migration is a two way movement of an animal to and
from an area with regularity or with changes in life
history strategy – example Waterfowl, big game in
Mountain west, African ungulate migration
Niche (Elton 1927)
 Ecological Niche = abstract concept but in general
means the role or function of organism in biotic
community (it’s occupation)
 Multidimensional : where it seeks food, when it feeds,
what size food it eats, where it reproduces
 Example elk and mule deer on winter range – overlap
somewhat in habitat but elk hide in dense forest, mule
deer in shrub cover
Wading Birds
Each has its own niche
Bare
Annual
Ground Grass/forb
Perennial
Grass/forb
Young
Woodland
Shrub
Mature
Woodland
Bobwhite Quail
Ruffed Grouse
Cottontail Rabbit
Gray Squirrel
Wild Turkey
Woodchuck
White-tailed Deer
Grass-forb
Shrub
Shrub – small tree
Mature forest
Generalized schema of some common terrestrial vertebrates along a successional gradient
in an oak-hickory forest
 Fundamental niche – niche occupied by that organism
when there is no competition from other species.
 Realized niche – niche occupied by species when some
competition with other species is occurring.
Niche segregation
 Tendency for species that live in same area and require
similar resources to have niche requirements that
differ in one or more dimensions.
Niche segregation occurs when species that live in same area and
require similar resources differ in one or more dimensions of
habitat use (temporally or spatially).
Eat same food base, great-horned owl active @ night, red-tailed hawk active @ day
Eat same food base, coyote open habitat, bobcat forest habitat
Competition
 Competition occurs when
organisms in the same community
seek the same limited resource;
they have overlapping niche
requirements. Resource may be but
is not limited to such things like
food, light, space, water, nest sites,
etc.
 Interspecific competition: between
individuals of two different species.
 Intraspecific competition: among
individuals of the same species.
Competitive Exclusion Principle
No two species can simultaneously and completely
occupy the same niche for an indefinite amount of time.
“Styles” of Competition
 Exploitative competition occurs when individuals use
the same limiting resource or resources, thus depleting
the amount available to others.
(e.g. squirrel eats all the acorns from a tree and
leaves less or none for mice)
 Interference competition occurs when individuals
interfere with the foraging, survival, or reproduction of
others, or directly prevent their physical establishment
in a portion of a habitat.
(e.g. when coyote will not approach wolf kills or territory for fear of
being killed)
Outcomes of Competition
 Exploitative competition may cause the exclusion of one
species. For this to occur, one organism must require less of
the limiting resource to survive. The dominant species must
also reduce the quantity of the resource below some critical
level where the other species is unable to replace its numbers
by reproduction.
 However, exploitative competition does not always cause the
exclusion of one species. They may coexist, with a decrease
in their potential for growth. For this to occur, they must
partition the resource.
 Interference competition generally results in the exclusion of
one of the two competitors.