Midterm 2 Flashcards
Biodiversity
the variability among living organisms from all sources including, terrestrial, marine and other aquatic ecosystems and the ecological complexes of which they are part. It is also the variety of species and ecosystems on Earth and the ecological processes of which they are a part; three levels (genetic, species, ecosystem)
Species richness
number of species present in an ecosystem or sample
Abundance
percent cover, biomass or frequency of individuals per species
Abiotic
non-living physical and chemical factors that affect the ability of organisms to survive and reproduce
Biotic
living factors; all the living things that live within and shape an ecosystem
Population
the number of individuals of a species within some area at some point in time
Ecosystem
dynamic interrelated collections of living and non-living components organized in self-regulating units
Hypothesis
testable statement about the natural world that can be used to build more complex inferences and explanations
Evenness
relative abundance of species in an area. (Often given as “Shannon’s index”)
Woodlot
forest in a city (urban forest); remnant forest in a farmer’s field
Community
group of species living in an ecosystem at some point in time
Population growth
Pt2 = Pt1 + (B) - (D) + (I) - (E), change in the number of individuals during some period of time
Carrying Capacity
number of individuals who can be supported in a given area within natural resource limits, and without degrading the environment
Obligate
must live with it’s partner species
Facultative
can live without its partner species
Mutualism
both species derive a mutual benefit, for example an increased carrying capacity
Neutralism
the relationship between two species which interact but do not affect each other
Predation or parasitism
interaction between organisms or species, in which one organism or species benefits at the expense of another (antagonism
Competition
the fitness of both species is lowered by the presence of the other
Commensalism
benefits one organism and the other organism is neither benefited nor harmed
Amensalism
a product of one organism (i.e. chemical compound) has a negative effect on another organism
Ecosystem processes
energy flows and the cycling of materials
dendrochronology
tree age based on the number of rings
Point diversity
spatial scale decreased to microhabitats
Gamma diversity
spatial scale increased to include multiple woodlots in a township at a broader landscape scale
Physiognomy
the most dominant vegetation in a forest
Alpha diversity
is the number of species in a local forest stand (inventory diversity)
Low Beta diversity
two ecosystems share the similar species and respective abundance
Niche
a set of biotic and abiotic conditions in which a species is able to persist and maintain stable population sizes
Habitat
a region in environmental space that is composed of multiple dimensions, each representing a biotic or abiotic environmental variable
Functional trait
an attribute of a species that defines them in terms of their ecological roles, such as how they interact with the environment and with other species
Functional diversity
a biodiversity measure based on functional traits of the species present in a community
Ecosystem engineers
organisms that directly or indirectly modulate the availability of resources to other species, by causing physical state changes in biotic or abiotic materials
IDH
maximum species richness in many systems occurs at an intermediate level (of intensity or frequency, or both) of natural disturbance
Ecosystem function
characteristic exchanges within an ecosystem such as energy and nutrient exchanges, decomposition and production of biomass
Adaptive management
uses management intervention as a tool to strategically alter the functioning of an ecosystem
Comanagement
the sharing of authority, responsibility, and benefits between government and local communities in the management of natural resources
Scientific method
Observation & Assumptions - Hypotheses - Predictions - Experiment - Monitoring - Evaluation
Fundamental niche
all the possible dimensions in which a species can survive in principle
Realized niche
the dimensions in which a species actually survives after the effects of biotic interactions
Community assemblages
development of an ecological niche in a forest along a gradient of time
Density dependent
regulation of a population by changes in per capita birth or death rates in response to density
Density independent
regulation of a population by changing only the population size (not the factors affecting carrying capacity)
Ecological biogeography
the account of the present day distribution of species in terms of abiotic and biotic factors
Historical biogeography
the reconstruction of speciation, dispersal, establishment, distribution and extinction of species
Range
The area or location inhibited by species for a defined amount of time
Endemic
evolved there and only found there
Vicariance
the physical splitting of a population into smaller, isolated populations by a geographic barrier
Nutrients
elements whose supply tends to limit biological activity
Recruitment
number of new individuals reaching breeding age, including immigration
