Midterm Flashcards
Fundamental niche vs realized niche
fundamental - the multidimensional set of conditions an organism needs to survive
realized - the actual niche of a species whose distribution is restricted by biotic interactions (competition, predation, disease, parasitism)
competition
the tendency of plants to utilize the same quantum of light ion, mineral nutrient and molecule of water
competitive exclusion principle
two species with identical niches cannot coexist indefinitely, therefore coexisting species should occupy different niches
the study by robert and John mcarthur included foliage height and bird species diversity, what was the outcome?
- forests with greater foliage height diversity support high bird species diversity
- plant communities with low foliage height diversity support low bird species diversity
what is the paradox of the plankton
although resources needed are constant, heterogenicity in abiotic conditions and resource distributions allow coexistence
- plankton lives in open waters and compete or the same nutrients (N,P,Silica) but they coexist
- exclusion or coexistance is dependent on ratio of silicte and phosphate not absolute amount of nturients
david tillman did a study on the niches of algae, what was the outcome?
two species could coexist where the population of each is limited by a different nutrient
- cyclotella dominates where silicate is most limiting to pop growth and asterionellla dominates where phosphorus is most limiting to pop gorwth
- when each pop is limited by a nifferent nutrient there is coexistance!
tillmans landmark work clearly shows what?
that heterogeneity in resourse ratios, a form of environmental compelxity, influence community structure
tillman state for a given species (2 things)
what are the resources and how variable the resources are
what was robertsons study in the abandoned agricultural field?
studied NO3 concentrations and moisutre over 0.5 hectar area with 301 sample points
- they found there was a >10fold difference in measured variables, and little correlation between NO3 and moisture, there was sufficient spatial variability to affect plant community structure
what was the study with bell and factors affecting sedge distributions in deciduous forests?
- utilized 11 clones of widespread carex species
- established 3-1000m transects in differnt areas and transplanted the clones at 10m intervals
- survived in areas of higher diveristy
Ecology
the study of interactions among organisms and their environment
Population ecology
Scientific study of structure and dynamics of populations
Community ecology
the study of interactions occurring within a prescribed area between species (interspecific) and between species and their environment and the effects this has on community structure and function
Interactions determine _______ level responses
community
what is an ecological service?
communities do things if there are societal benefits these are call
what is community structure?
- number of species S (richness)
- Relative abundance of species
- which species are present and aren’t present
- horizontal, vertical, and diagonal linkages
species diversity takes into account both ________ and _______
numbers and abundance
differentiate alpha beta and gamma diversity
alpha - diversity found within a small area (ex. patch of forest or grassland)
beta- diversity is a measure of how different patches are from each other
gamma - diversity is the total diversity found within the entire area, which includes all
** what are some alternatives to species based approaches?
a taxon approach - focus on related species ex. gray wolves, eastern wolves, coyotes etc
A guild approach - ex. seed eating of Borel forest includes mammals, birds, insects, all interact to form a community, not all taxonomically related
Life form approach - ex. non species based approach based on location of overwintering buds, including ranker life for, based on location of the buds that give rise to new shoots
Functional approach - ● Based on how plants make a living (different photosynthetic pathways) C3, C4, CAM plants
Guild
a group of organisms that make their living in a similar way
Dominance
one or more species are substantially more abundant than other species
_______ ______ is one of the most fundamental aspects of community structure
relative abundance
what is log normal distribution?
bell shaped curve, most species have an intermediate abundance
log normal distribution is affected by ?
sample size
the more species sampled the more _____ species observed
rare
you see a more intense distribution when you sample more comprehensively meaning ____ ______ ______ because of rarer species found
left hand sided
how do you find the Shannon Weiner index?
you find the p value which is the # of individuals found for the species divided by the total individuals (do this for each species) then you multiply each p value by log(p) then you sum all the p values and apply the -
the greater the diversity index means?
the more diverse the community
pilous J measures species ____
eveness
evens ranges from ___ - _____
0-1
how do you find pilous J?
the Shannon weir index divided by logS which is species richness (ln5)
what does evens describe?
the distribution of individuals
with rank abundance curves, the more horizontal the slope the ______ the evenness
greater
there is a strong correlation between habitat diversity and _______ level diversity
community level
diversity increases with evens (T/F)
T
for rank abundance curse the abundance rank is the ________ species and the proportional abundance is the _____ value
total #, p
what is the difference between the node and the internode with plants?
node - point of attachment for each leaf
internode - space between the node
what does it mean to propagate plants?
take a piece from the node and it will produce an axillary bud and adventitious roots
diversity is important for richness, abundance, diversity and spatial distribution (T/F)
T
what is the difference between fens and bog?
fens - groundwater fed, mineral rich, higher pH
Bogs - rainwater fed, lower nutrients, minerals and pH is lower
the northern hemisphere has ____ of all peatlands
1/3
describe the 2 main ways to evaluate the impacts of biodiversity on the delivery of ecological services?
- establish a species pool (gamma diversity)
2. choose a subset and grow in experimental plots (alpha diversity) and compare productivity
what was the reich study in cedar creek Minnesota?
they studied grassland communities in which they used measurements of 9x9 areas and 13x13m plots, and tested the relationship between biodiversity and ecological services
What causes diversity function relationships?
a given ecological service will be highest in which a community has the highest microenvironment
Balvanera studied what?
summarized 103 studies
- rarified the relationship between diversity and procuvtivity
- diversity affects primary consumer/producer abundance rise versa along with secondary and tertiary
Complementarity
- a given ecological service will be highest/fastest in a community in which all resources/micro-environments are being exploited or occupied
- a single species may not occupy the full niche space available
- function will increase until all niche space is exploited
Facilitation
some species enhance the growth of other
- reducing soil salinity, modifying water availability, nurse plants
the study with the Caddisflies, was facilitation or complementarity?
facilitation as filter feeding was typically higher in mixed groups with different species than single species groups.
zhu studied the genetic diversity with rice crops, what was the outcome?
- mixed genotype planting vs monocultures were more effective at reducing disease
- eliminated the need for fungicide
