Ecology Final

Front 1

what is an ecological community

Back 1

association of multiple populations

Front 2

species associations are the result of..

Back 2

historical development shaped by environment

Front 3

what are some internal structures in ecological communities?

Back 3

species richness, taxonomic composition, species dominance, community size

Front 4

________________________ typically study the structure and history of ecological communities, and the interactions between species that yield community structure.

Back 4

community ecologists

Front 5

what are emergent properties

Back 5

ecological functions that are greater than the sums of their individual populations

Front 6

what is an example of an emergent property?

Back 6

species richness

Front 7

what did Frederic E Clements believe?

Back 7

that communities were natural units of species associations that functioned as a super organism and that that specific communities were fixed

Front 8

what is the establishment phase/ species succession?

Back 8

process of change in the species structure of an ecological community over time

Front 9

what did Henry A Gleason believe?

Back 9

communities were little more than independent coicidential associations of species that co-ocurred because they had similar resource needs and environmental tolerances

Front 10

what did robert whitaker do?

Back 10

showed that truth is close to gleason's concept of ecological community than to Clements

Front 11

whittaker used _________ analyses to show that community composition is determined by local species availability and by environmental gradients

Back 11

gradient analyses

Front 12

geographic boundaries of communities are defined by ____________ when boundaries are sharp

Back 12

ecotones

Front 13

how does habitat fragmentation affect ecotone dynamics?

Back 13

it changes the relative proportion of edge and interior habitats

Front 14

what is convergent evolution

Back 14

associates species with similar ecological relationships and similar morphological adaptations

Front 15

what is a famous example of convergent evolution

Back 15

similarities between desert plant communities in North America and Africa (they are not closely related despite looking the same)

Front 16

floristic analyses turned attention from _________ and _________ individual plant species to __________ plant species associations in a variety of ways

Back 16

describing; cataloging; describing

Front 17

what is individual abundance

Back 17

size of overall community, sum of population sizes

Front 18

what is rarefaction used for?

Back 18

comparing richness in communities represented by different size samples

Front 19

S=cA^z is the formula for...

Back 19

species-area relationships

Front 20

what is the equilibirum hypothesis

Back 20

the number of species in a given area is determined by an equilibrium between species addition rate and species extinction rate

Front 21

what is the disturbance hypothesis

Back 21

larger areas are more likely to contain a wider array of disturbance histories than smaller areas

Front 22

what is the habitat diversity hypothesis

Back 22

larger areas are more likely to incorporate greater habitat heterogeneity than smaller areas

Front 23

what is the passive sampling hypothesis

Back 23

as species disperse, larger habitats present them with bigger targets and one species will hit larger habitat areas than smaller ones

Front 24

what do the species that occupy any given community depend on?

Back 24

tolerance for interactions with other members of assemblage and the physical environments where the habitat occurs, the availability of propagules or colonists

Front 25

what is community eveness

Back 25

the relative evenness of abundance distributions among all the species presen

Front 26

If two communities have identical species richness, the community with ___________ is the more diverse

Back 26

greater evenness

Front 27

community diversity is less ___________ to sample size than species richness

Back 27

sensitive

Front 28

Ha is known as

Back 28

estimate of diversity in a given local area

Front 29

what is HB

Back 29

broader diversity of region in whoch a community occurs

Front 30

What is Hy

Back 30

diversity change in different communities within same region or along ecological gradients

Front 31

how do you find HB

Back 31

HB=Hy/Ha

Front 32

dominance is the result of ...

Back 32

interactions among species within the community and their environment

Front 33

what are trophic relationships

Back 33

how energy and materials pass through and cycle within communities

Front 34

what are null models

Back 34

when individuals in a sample are randomly assigned to the species in a community by computer simulation

Front 35

what are keystone species

Back 35

taxa whose impact on community structure is disproportionately strong for their actual abundace

Front 36

how do keystone species increase community complexity by

Back 36

limiting the influence of dominant competitors

Front 37

what is succession

Back 37

return to a stable state following disturbance

Front 38

what are autogenic successions

Back 38

determined by events or processes occuring within ecological communities

Front 39

what are alllogenic successions

Back 39

under control of events happening outside the community

Front 40

what are the stages of seral development

Back 40

facilitation, inhibition, and tolerance

Front 41

real seral trajectories are _____________

Back 41

context dependant

Front 42

periodic disturbance can "reset" seral trajectories to...

Back 42

earlier seral states

Front 43

what is the intermediate disturbance hypothesis

Back 43

intermediate levels of disturbance should foster the greatest biodiversity possible within a given community.

Front 44

stable communities often exhibit a great deal of ...

Back 44

post-climax mosaic structure

Front 45

what is taxonomic richness sensitive to?

Back 45

sample size

Front 46

reasons species diversity is important

Back 46

-repository for genetic history of life on Earth

-biotic organisms provide essential services to keep ecosystems functioning

-pest control

Front 47

The number and abundance of species in a given community likely reflects...

Back 47

the dynamic interaction of both regional/historic influences and local/deterministic interactions between species and their environments.

Front 48

what does the local/deterministic approach emphasize

Back 48

the importance of interactions between species populations within communities

Front 49

what does the regional/historic approach emphasize

Back 49

the role of evolution, speciation, biogeography, and population movement in determining the available pool of species that can occupy a community.

Front 50

what does the island biogeographic theory illustrate

Back 50

the regional and historic influences on species diversity, but allows for the influence of local/deterministic interactions.

Front 51

________________ is inversely proportional to distance from the mainland or other source pools

Back 51

colonization rate

Front 52

_______________________ is a function of island size (recall the general species-area relationship) and local/deterministic interactions among species on the island.

Back 52

extinction rate

Front 53

what is the time hypothesis

Back 53

long periods of environmental stability experienced by the tropics

Front 54

what is the spatial area hypothesis?

Back 54

there is a larger land (and ocean) area available in the tropics than in the temperate zone

Front 55

what is the environmental heterogeneity hypothesis

Back 55

tropics offer more habitat heterogeneity than the temperate regions.

Front 56

what is the predator hypothesis

Back 56

predator and parasite diversity is lower in the temperate zones, which fosters greater abundance of prey species

Front 57

_________ is strongly correlated with species richness

Back 57

Habitat heterogeneity

Front 58

what was charles elton an advocate of

Back 58

describing the structure of communities in terms of feeding relationships and interactions among consumers

Front 59

who articulated the trophic pyramid concept

Back 59

charles elton

Front 60

what were AJ Lotka's views based on

Back 60

he saw ecosystems as machines which, like all other machines, are constrained by the fundamental physical rules of mechanics and thermodynamics.

Front 61

raymond lindeman's trophic dynamic approach explained ..

Back 61

Elton's feeding pyramid observations as resulting from the energetic relationships between tropic levels within ecological communities

Front 62

Energy conversion inefficiencies result in some energy loss as________________________________________ or whenever it is passed from one organism to another.

Back 62

heat every time ecosystems transform energy from one form to another,

Front 63

energy flow through ecosystems is

Back 63

irreversible

Front 64

what did eugene odum formalize

Back 64

study and representation of energy/matter flux/transfer relationships between ecosystem components

Front 65

Living systems consistently maintain (lower/higher) steady state energy states than similarly sized non-living systems in the same environment

Back 65

higher

Front 66

________________ through ecosystems is one of the processes responsible for organizing interactions among organisms within ecosystems

Back 66

flow of energy

Front 67

Most energy enters terrestrial and aquatic biological pathways through...

Back 67

photosynthesis of carbohydrates that are subsequently used as the basic building blocks of all other biological molecules

Front 68

____________________ is the autotrophic loading of biomass into the lowest levels of ecosystem food chains,

Back 68

primary production

Front 69

______________________ is the total amount of energy fixed by photosynthesis

Back 69

gross primary production

Front 70

_______________________ is the actual accumulation of plant biomass

Back 70

net primary production

Front 71

__________________ is the heterotrophic conversion of biomass from one form (a resource) to another (a consumer)

Back 71

secondary production

Front 72

where is the potential rate of photosynthesis highers?

Back 72

warm tropics

Front 73

what is photosynthesis limited by

Back 73

nutrient and water availability

Front 74

what is the compensation point

Back 74

rate of photosynthesis that exactly balances the rate at which energy is lost via respiratory maintenance

Front 75

The compensation point (decreases/increases) with temperature because plant metabolism is sensitive to temperature

Back 75

increases

Front 76

high photosynthetic rates are accompanied by (high/low) water transpiration rates

Back 76

high

Front 77

what is photosynthetic efficiency limited by

Back 77

water availability in terrestrial environments

Front 78

Aquatic plant production is usually limited by ______________

Back 78

mineral nutrient availability

Front 79

what is assimilation efficiency

Back 79

proportion of available resources consumed and digested that are actually assimilated into the next higher trophic level

Front 80

assimilation deficiency depends on

Back 80

dietary quality

Front 81

Net production efficiency is (highest/lowest) for animals with high maintenance costs

Back 81

lowest

Front 82

that only about 10 percent of the energy from each lower trophic level is _____________

-energy (biomass) at the next higher trophic level— 90 percent is _____ in one form or another

Back 82

converted to stores; lost

Front 83

Local matter cycling is largely composed of _________________ from organic sources

Back 83

nutrient regeneration

Front 84

Matter moves between global pools at rates that are determined by both _________and_______ processes.

Back 84

biotic and abiotic

Front 85

_________________ of biological carbon compounds releases the stored energy

Back 85

Oxidation

Front 86

what is an example of a carbon sink

Back 86

ocean, atmosphere,

Front 87

what is an example of a carbon source

Back 87

fossil carbon deposits

Front 88

However, when terrestrial plant growth is not limited by nitrogen availability, it is often limited by _______________

Back 88

phosphorus

Front 89

Recall that the ultimate sources of all mineral nutrients are elements derived from

Back 89

bedrock

Front 90

Ecosystems therefore rely extensively upon ____________ from organic storage pools to return nutrients back to organic use

Back 90

nutrient recycling

Front 91

organic nitrogen is ultimately _________to NH3, which oxidizes to ______ in aerobic habitats before reuptake by plants.

Back 91

ammonified; NO3

Front 92

how do nutrient regeneration in terrestrial and aquatic ecosystems differ?

Back 92

most terrestrial nutrient regeneration occurs close to the sites of nutrient uptake by primary producers, while in aquatic systems nutrient pools are often strongly sequestered from producers

Front 93

when are nutrients lost in terrestrial soils

Back 93

-when they are converted into biologically inaccessible forms

-when they are transported out of the ecosystem in solution

-when biomass is removed or harvested.

Front 94

what is leaching

Back 94

nutrients are lost to ecosystems

Front 95

what cant leached nutrients be used?

Back 95

they are carried deeper into the underlying soil, below the capacity of plant roots to access them, or they run off at the surface or below ground, carrying nutrients into rivers

Front 96

H+ ions have the (lowest/greatest) affinity for soil particles

Back 96

greatest

Front 97

acid soils lose nutrients (more/less) quickly than relatively neutral soils

Back 97

quickly

Front 98

In terrestrial environments, _________ is the primary proximal pool for nutrient regeneration.

Back 98

detritus

Front 99

what do lateritic oxisols do

Back 99

retain nutrients poorly and become hard, barren crusts within a few years of vegetation removal.

Front 100

Shallow roots ________ nutrient loss in tropical forests by capturing nutrients before they have time to leach through the upper soil layers.

Back 100

minimize

Front 101

In contrast with tropical wet forests, the nutrient residence time in temperate forest detrital pools is usually much (longer/slower)

Back 101

longer

Front 102

_______________ enhace root zone nutrient uptake rates by terrestrial plants, helping to capture nutrients before they have an opportunity to leach away

Back 102

mycorhhizal

Front 103

Primary production in aquatic ecosystems occurs in the ______ zone near the surface

Back 103

photic

Front 104

decomposition occurs primarily within the ________ sediments

Back 104

benthic

Front 105

Nutrient budgets in most aquatic ecosystems (especially freshwater systems) are dominated by __________ nutrient inputs

Back 105

allochthonus

Front 106

__________________________ serves to link upstream ecosystem processes with downstream processes

Back 106

nutrient transport

Front 107

what is the River Continuum Concept

Back 107

connects ecological processes in any single portion of flowing water habitats with the organisms and processes that occur upstream and downstream