Chapter 15: Communities and Ecosystems Flashcards
Community
Assemblages of species with the potential for interactions
Interspecific community
Between members of different species
Intraspecific community
Between members of the same species
Ecological niche
Role/use of resources in a community leads to competition for those resources
Competition (competitive exclusion)
This can lead to if niches are too similar (one species out-competing)
Mutualism (+/+)
The relationship that benefits both members
Commensalism (+/0)
One species benefits, the other is unaffected
Exploitation (+/-)
One species benefits and the other is harmed
Predation
One species kills/eat another
Exploitation leads to
Extensive natural selection
Exploitations developing to
Cryptic coloration (camouflage) and warning coloration (anti-camouflage) and also associated with mimicry
Exploitation: Herbivory
One species eats all or part of a plant (often non-fatal)
Exploitation: Herbivory leads to extensive
Natural selection toward defensive mechanisms like physical (thorns, hairs, and spines, etc) and chemical (bitter/toxic compounds)
Parasitism/Pathogens
A parasite/pathogen uses the host for its benefit
Parasites include the following:
1) External or internal
2) Long-term or temporary
3) Bacteria, fungus, protist, animal, or plant
Species diversity
Measurement of a variety of species making up the community
Species richness plus with
Relative abundance
(# different species) plus with
(Proportion of community)
Species diversity typically needs to
Maintaining diversity to maintain the system
Keystone species hold
Their communities together
Disturbance
The event that changes the community (drought, flood, fire, etc.)
Disturbance is
Good or bad
Disturbance leads to
Successions like primary (no life, life) and secondndary (some life, more life)
Ecosystems
Community + abiotic environment, like water, temperature, nutrient/mineral content
Two critical processes of ecosystems
Energy flow + nutrient cycling
Trophic interactions
Feeding relationships throughout the community
Energy flow sequence of energy transfer equal to
Food chain
Producers
Photosynthesis
Primary consumers
Herbivores
Secondary consumers
Carnivores eating herbivores
Tertiary consumers
Carnivores eating carnivores
Detrivores/decomposers
Eat/recycle wastes from all levels
Reality food webs showing
All potential food chains in a community
Food webs can be both
A primary and secondary consumer, or eat a variety of prey items
Energy flow each transformation of energy equal to
Loss of available energy
Energy flow loss biomass as you move up
The food web (as shown in ecological pyramids)
Biological magnification
Being at the top is not always good
High-level consumers accumulate much
Higher levels of toxins due to increasing concentrations in the food chain
Nutrient cycling is chemicals necessary for
Life must be reused by cycling through a system
Low availability (normal)
Restricted growth
High availability (artificial)
Excessive growth
Fertilizers, detergents, and other wastes cause
Algal blooms (such as red tides) and are deadly
Large scales extraction of carbon stores (fossil fuels) support
Global climate change
Biodiversity
The measure of variety of living things through three diversities:
1) Genetic diversity
2) Species diversity
3) Ecosystems diversity
Biodiversity lost through
Habitat destruction, invasive species, overexploitation, and pollution
Conservation biology aims to
Preserve and restore biodiversity
Conservation focus on
Biodiversity hot spots
Biodiversity hot spots areas with
Unusually high species diversity and many endemic species (only found there)
Conservation save one
Species (the whales! the pandas) makes more sense to focus on saving the community or ecosystem
Conservation increasing concentration on
Restoration, prevention of loss and sustainability
