Mutualism
Both participants benefit-- obligate for one or both
Commensalism
one benefits and one is unaffected-- obligate for one but not the other
Amensalism
one is unaffected and one is harmed-- not obligate for either
Feeding Guilds
use same ecological resource in a similar way
True Predator
eats multiple prey, death usually involved
Carnivore
flesh-eating animal
Grazer
eats parts of multiple prey, but usually doesn't kill it
Herbivore
animal that consumes plants
Scavenger
Organism that eats dead or decaying matter (doesn't kill prey)
Detritivore
Scavenger that eats decomposing or dead organic matter in soils or sediments
Omnivore
consumes a range of prey types
Parasite
-obtains nutrition from single or alternate hosts, but usually don't kill the prey
-live in or on host, and derive nutrition from that host
-often involve alternate hosts for different life cycle stages
Parasitoids
single prey eaten by one or more young, and death is always involved
Functional Response
the rate of prey capture per predator, as a function of prey density
Asexual Reproduction
-produces individuals that are genetically (no fusion of egg or sperm)
- Common in archaea, bacteria, and protists (unicelled)
-2N-2N
Sexual Reproduction
-Produces individuals that are genetically different through syngamy (joining of egg and sperm)
-Offspring differ from parents and siblings
-Common in mammals, birds, reptiles, plants
Red Queen Hypothesis
is an evolutionary hypothesis which proposes that organisms must constantly adapt, evolve, and proliferate not merely to gain reproductive advantage, but also simply to survive while pitted against ever-evolving opposing organisms in an ever-changing envi
Endoparasites
live and feed inside host
Ectoparasites
live and feed outside host
Lotka-Volterra model
-model builds on the exponential growth equation by including an encounter rate between predators and prey that reduces the prey population growth
-predicts regular, even cycles of predator and prey populations, with predator cycles following prey cycle
Handling time
amount of time it takes a predator to kill and consume one item of prey
Type 2 Functional Response
-most common- predators rate of prey consumption increases with increasing prey density, but not in direct proportion
-as prey densities get higher, the rate of increase in consumption rate get smaller, and gradually levels off at a maximum rate of predat
Generalists
an organism that can exploit several different species or take advantage of a broad set of environmental conditions
Specialists
an organism that can exploit only one species or can only advantage of a narrow set of environmental conditions
Type 1 Functional Curve
predation rate increases linearly with increasing prey density
Type 3 Functional Curve
S shaped curve-- Predation rate increasing more slowly at a low prey density, then more quickly at high prey density
Co-evolution
occurs when 2 species that live in close association both adapt in response to selective pressure from the other
The Fundamental Niche
Complete set of environmental conditions (physical, chemical, & biological) in which a species can potentially survive and reproduce not including interspecific interactions such as competition, predation, and parasitism
The Realized Niche
what remains available to the species once competition, predation, and parasitism are taken into account
Competition
when two (or more) individuals attempt to use the same resource -- causing one or more (usually both) of the participants to suffer a net fitness loss
Resource (indirect/scramble)
-use of a resource indirectly reduces its availability
-share of resources depends on amount available & population density
-Typical of groups without social structure
Interference (direct/contest)
-individuals (usually of the same species) directly interact in an attempt to reduce the other's access to resources
- doesn't include fighting
- less density-dependent than resource competition
Character Displacement
-The concept of limiting similarity & and the process of character displacement
- Competition causes the phenotypes of competing species to evolve to become more different over time
Allopatry
one species occurring in absence of the other
Sympatry
two (or more) species occurring in the same geographic location
Allelopatry
type of interference competition between plants involving the production and release of secondary chemicals by one species or individual that inhibits growth, survival or reproduction of another
Preemption
interference competition that occurs when an individual prevents other individuals from occupying a location by occupying the space first
infraspecific competition
competition between individuals of the same species
interspecific competition
occurs when individuals of one species limit the resources available to another species
Competitive Exclusion
two species that use a limiting resource in the same way cannot coexist indefinitely
Resource Partitioning
Use of limiting resource in different ways
Communities
-Assemblages of populations
- All the (potentially interacting) species
-in the same place at the same time
Ecological Community
all species occurring in the same place/time whose interactions we can detect (and about which we care)
Food Webs
organize species based on their trophic or energetic interactions; comprised of the sum of its trophic levels
Ecosystem Engineers
species that create/modify/maintain physical habitat for themselves and these changes benefit other species
Succession
changes in community composition over time
Allogenic
changes in the physical environment (abiotic)
Autogenic
Changes that are the direct result of organisms within a community (biotic)
Primary Succession
the development of plant and animal life in an area without topsoil; the development of biotic communities in a previously uninhabited and barren habitat with little or no soil
Secondary Succession
previously occupied substrate, residual organisms and organic matter
Life-history traits
differences in physiology & behavior that make each species well suited to grow in particular environments
Facilitation Model
early successional species make the environment more suitable for late successional species
Inhibition Model
early successional species make the environment less suitable for other species
Tolerance Model
early successional species have little or no effect on the growth of the late successional species
Resistance
the ability to withstand a disturbance
Return Time
the time required to return to equilibrium after disturbance
Resilience
how closely the post-recovery community resembles the pre-distubance community
Hyseteresis
when the reversal of change may not result in a return to the original conditions if the original shift was sufficiently large enough
Community Importance (CI)
compares a measurable ecosystem trait before and after the species is removed from the community
Total Impact (TI)
is the magnitude of change that results from removal, regardless of change direction
Biodiversity
the sum of an area's organisms, considering the diverse of species, their genes, their populations, and their communities
Species Diversity
the number or variety of species in a particular region
Species Richness
number of species
Species Evenness
extent to which numbers of different species are equal or skewed
Species
a particular type of organism; a population of populations whose members share certain characteristics and can freely breed with one another and produce fertile offspring
Genetic Diversity
how diverse are individuals within species or sub-species
Phylogenetic Diversity
how closely or distantly related are species in the community
Functional Diversity
to what degree do species in the community serve the same or different function
Ecosystem Diversity
diversity of higher levels of organization above species and populations
Alpha Diversity
local community
Gamma Diversity
regional species pool
Beta Diversity
change in composition as you move from one local community to another (i.e., species turnover)
Extripation
disappearance of a particular population, but not the entire species globally ("local extinction")
Extinction
last members of a species dies and the species vanishes forever from Earth
HIPPO
Habitat alteration, Invasive species, Pollution, Population growth, Overexploitation
Biophilia
innate human love for and attachment to other living things
Conservation Biology
Scientific discipline devoted to understanding factors, forces, and processes that influence the loss, protection, and restoration of biological diversity within and among ecosystem
US Endangered Species Act 1973
-Restricts actions that would destroy endangered species or their habitats
-Forbids trade in products from species
-Prevents extinction, stabilizes and recovers populations
Convention on International Trade in Endangered Species of Wild Fauna and Flora 1973
CITES
it bans international trade and transport of body parts of endangered organisms
Convention of Biological Diversity (CBD)
Conserve biodiversity, use it sustainably, and ensure fair distribution of its benefits
Biodiversity hotspot
an area that supports an especially high number of species endemic to the area, found nowhere else in the world