Communities: Basic patterns and Elementary Processes Flashcards
Major Community
Self-sustaining and regulating
Makes up major communities;
rely on interactions with other
communities.
Minor Community
It examines interactions between species in groups over a wide range of temporal and spatial
scales, including distribution, population dynamics, structure, abundance, and demography.
Community Ecology
Community ecology primarily focuses on the ______________ as influenced
by particular genotypic and phenotypic traits
interactions among populations
defined by discrete habitat
boundaries
Physically defined
Communities
The Physically defined
Communities includes asemblages of species found in a particular place or habitat. An example of this is ___________.
Biomes
usually recognized by the presence of one or
more conspicuous species that dominate the
community
Taxonomically defined Communities
consist of sets of species whose abundances are significantly correlated
Statistically defined Communities
- consist of subsets of species in a particular place or habitat whose interactions significantly
influence their abundances.
Interactively defined Communities
a
dynamic interactive
system of interdependent
populations
Community
Assemblage of populations
that live in environment and
interact, forming a distinct
living system with its own
composition, structure,
environmental relations,
development, and functions
Community
Examines interactions between species in groups over a wide range of temporal and spatial
scales, including distribution, population dynamics, structure, abundance, and demography.
Community Ecology
includes assemblages of
species found in a particular
place or habitat
Physically defined
Communities
defined by discrete habitat
boundaries
Physically defined
Communities
Give 5 examples of BIOMES
*Tropical rain forests
*Temperate rain forest
*Taiga forests
*Savannas
*Tundra
*Deserts
*Coral reefs
usually recognized by the presence of one or
more conspicuous species that dominate the
community
Taxonomically defined Communities
consist of sets of species whose abundances are significantly correlated
Statistically defined Communities
consist of subsets of species in a particular place or habitat whose interactions significantly
influence their abundances
Interactively defined Communities
Biotic Elements of Communities
*Autotrophs
*Heterotrophs
*Decomposers
manufacture their own food using energy from
the sun to perform photosynthesis
Autotrophs (primary producers)
obtain their nutrition from other organisms
Heterotrophs (consumers)
consume dead plant or animal material
Decomposers
total number of different species in a community
Species Richness
calculated simply by recording the number of different species in an area
Species Richness
number of different species present in a community and relative abundance of each of
those species
Diversity
It’s based on Claude Shannon’s formula for entropy
and estimates species diversity
Shannon diversity index
The index takes into account the number of species living
in a habitat (________) and their relative abundance (_________).
*richness
*evenness
It break down the tissues and other organic
matter which has not been consumed by animals higher
in the food chain
*Decomposers
*Detritivores
These organisms (decomposers and detritivores) recycle the
nutrients back into the soil, playing a vitally important role in the _______ and _______ cycles
*carbon
*nitrogen
-Some species exert a more _______ influence
over the function and structure of the community
than others
dominant
(May be) responsible for modifying the conditions
of abiotic conditions of a habitat
Dominance
(May be due) to physical size, population number,
or activities that has impact upon other organisms
or environment
Dominance
3 Main Forms of Interdependence
- Nutritional interdependence
- Reproductive interdependence
- Protective interdependence
describes the transfer
of energy and nutrients through feeding
Nutritional interdependence
is when certain
species is only able to reproduce on a particular
substrate and are therefore dependent on the presence of this within the community
Reproductive interdependence
is observed when an
organism require a level of shelter and rely on other
organisms within the community
Protective interdependence
The process by which the
mix of species and habitat changes over time.
Ecological succession
Succession stops temporarily when a “______”
community forms.
climax
the initial colonization of a
bare landscape which has not been previously
occupied
Primary succession
During this succession, organisms
must start from scratch.
Primary succession
is the “endpoint” of succession within the context of a particular climate and
geography.
Climax community
This community will persist in a given location until a disturbance occurs
Climax community
occurs where a community
has existed previously but has been removed from a
landscape
Secondary succession
Happens when a climax or intermediate
community is impacted by a disturbance.
Secondary succession
Restarts the cycle of succession, but not back to
the beginning – soil and nutrients still present.
Secondary Succession
Refers to the variety of life on Earth at all its levels, from genes to ecosystems, and can encompass the
evolutionary, ecological, and cultural processes that sustain life.
Biodiversity
SAR
Species-area relationship
Large areas contain more species than small areas
Area and Species Richness
Species richness, at broad spatial scales, tends to increase with an increase in primary
productivity
Productivity and Species Richness
At smaller spatial scales, the relationship between productivity and species richness is
more varied; both ______ and ________ relationships occur
*positive
*negative
higher species diversity lead to ___________.
higher ecosystem productivity
2 Mechanisms underlying Diversity-Productivity relationship
- Niche complementarity
- Species selection
occurs when species differ in the way they use limiting
resources
Niche complementarity
this lead to increased productivity with increased species richness
if diverse communities are more likely to contain more productive species that come to dominate the community
Species selection
total biomass or total species abundance
Temporal stability of communities
communities that are more resistant to invasion by exotic species than are less diverse communities, but this “biotic resistance” does not allow
them to repel invaders indenitely or at larger spatial scales
Species-rich experimental
It tends to
be greater in more diverse communities due to asynchrony in species responses to
environmental fluctuations
Temporal stability of communities
a measure of disorder and affects all aspects of our daily lives.
entropy
