b50 lec 10,11,12 Flashcards
the series of changes in the species composition of a community through time at a particular location that occur in a fairly predictable way as a result of abiotic and biotic influences, as the location goes from bare rock or lifeless water to being filled with interacting species
ecological succession
refers to succession that begins in/on substrates that contain NO organisms and NO organic material, tends to be slow, as the first colonists must arrive from elsewhere, and it is only through the actions of these species that the environment becomes suitable for the establishment of species in later seres
primary succession
what determines whether primary, secondary or little succession change occurs
frequency and intensity of disturbances
occurs following a disturbance where some, but not all organisms have been destroyed
secondary succession
what does r stand for
intrinsic growth rate
what does K stand for
carrying capacity
early successional species tend to be
r-selected
late successional species tend to be
K-selected
r species characteristics are
small, high reproductive rate, low survival rate, short generation time, rapid development, early maturity, high dispersal ability
K species characteristics are
large, low reproductive rate, high survival rate, long generation time, slow development, late maturity, low dispersal ability
what takes longer primary succession or secondary succesion?
primary succession
early species modify the environment in ways that benefit later species.
facilitation model
- the sequence of species faciliations leads to a climax community
early species modify the environment in ways that neither benefit nor inhibit later species
tolerance model
early species modify the environment in negative ways that hinder later successional species
inhibition model
- succession requires disturbance for succession to continue
guiding principles outlining how the timing the species arrival or the initial suite of colonizing species can determine the species composition of the community
assembly rules
provides many large scale “experiments” on community succession and applies successional principles for management. It aims to manage highly degraded or newly established sites by providing conditions that make sites physiolocially tolerable for a diverse array of species to accelerate succession towards a desired endpoint community.
restoration ecology
an integral part of all ecological systems. depending on the type, frequency and intensity, _________ may reset successional processes, or enable them
disurbance
suggests that diversity will be greatest at intermediate levels of disturbance
intermediate disturbance hypothesis
we refer to a system as ________ is there are two different stable equilibria to which the system can be attracted
bistable
the destructive use of animals, plants, and their products for various consumptive (food, medicine) and non consumptive (ex. trophy hunting) processes
exploitation or harvesting
harvesting wild organisms at rates that are faster than the rates at which they can recover
overexploitation or overharvesting
why has fish size become substantially smaller over time?
because when we fish, we want the big fish, so the bigger fish are gone first
fish have evolved to be smaller so they are less wanted
what three things does “land use change” involve
habitat degradation
habitat fragmentation
habitat loss
any time we convert land from one use to another
land use change
changes that reduce the quality of a habitat
habitat degradation
occurs when a natural habitat becomes incapable of supporting its native species
habitat loss
occurs when continuous habitat is broken up into smaller pieces
habitat fragmentation
changes that occur/begin at the boundary of two habitats, such as road mortalities, disease spillovers etc
edge effects
what can habitat fragmentation lead to?
edge effects (changes that occur/begin at the boundary of two habitats, such as road mortalities, disease spillovers etc)
also
can lead to increased contact between humans and wildlife (an edge effect)
also
can facilitate the invasion and establishment of non-native species
the movement of an individual to a new location, typically without returning
dispersal
a species that is 1: present in a location where they didn’t evolve and 2: was moved there via human action
non-native species
- cause little to no harm or many have been beneficial to human societies
a species that is 1: present in a location where it did not evolve, 2: was moved there via human action, and 3: has spread in its new location, producing negative impacts on the environment, human health, or economic systems
invasive species
are physiological effects usually biggest on ectotherms or endotherms
usally direct on ectotherms and indirect on endotherms
the timing of periodic biological phenomena that are correlated with cyclic or seasonal events
phenology
if the timing of events shifting in different manners for interacting species
phenological mismatches
suggests that higher biodiversity leads to reduced disease
so lower biodiversity levels leads to increased disease
dilution effect
a mission-oriented science that focuses on how to protect and restore biodiversity
conservation biology
deals with understanding how anthropogenic change has affected/will be affecting ecosystems
global change ecology
the collaborative efforts of multiple disciplines working locally, nationally, and globally to attain optimal health for people, animals, and our environment
one health
describe how the number of species that were identified increases with the number of individuals sampled
species accumulation curves
- species accumulaiton curves are initially steep but then level off once most species have been identified (the more you sample, the less likely it is that you see something new)
- leveling off of the species accumulation curve can indicate adequate representation of the community in the samples
how do we know when our sampling efforts have captured a community’s species richness and composition adequatley
when the species accumulation curve levels off
collecting data at multiple spatial scales at randomly chosen locations allows understanding how community composition might vary across different areas
Hierarchial sampling designs
suggest that the number of species that are found will increase with the area sampled
species area relationship
- steeply first, and then more slowly as the probability increases that sampled species have already been observed in previous areas (similar to species accumulation curves)
the number of species in a community
species richness
describes how evenly individuals are spread among species by considering the relative abundances of each species compared to one another
species evenness
plot the proportional abundance of each species (pi) relative to the others in rank order, can be used to understand whether differences in diversity are due to differences in species richness, eveness, or both
Rank abundance curves
graphically depict the evolutionary relationships among a set of species. the length of branches typically represent the time since evolutionary divergence from the previous note.
phylogenetic trees
can be measured by adding up all branch lengths within a phylogeny to create a single number that can be compared across locations and through time
phylogenetic diversity (PD)
characteristics of species that describe their ecological roles in a community, including how that species interacts with other species and with the envionrment
functional traits
graphically depict the relationships among a set of species in terms of their functional traits
functional diversity dendrograms
the number of traits present in a community
functional richness
the proportion of individuals in each functional group
functional evenness
species richness across different habitats can be described using:
alpha, beta, and gamma diversity
species richness across a region made up of smaller localities
the average number of species
gamma diversity is a product of alpha and beta diversity
gamma diversity
the average number of species found within small, local-scale habitats in a region
alpha diversity
a measure of heterogeneity of community composition among localities
beta diversity b = y/a
the total number of species on Earth (global species richness)
the evolutionary diversity represented by these species
the diverse communities and ecosystems that these species build
biodiversity
the number of species in a community
species richness
describes how evenly individuals are spread among species by considering the relative abundances of each species compared to one another
species evenness
a commonly used summary metric for species diversity, it incorporates both species richness and species evenness
Shannon-Wiener Diversity Index
a distinct location on the planet where species richness is relatively high
biodiversity hotspot
an increase in the taxonomic similarity of sites through time
biotic homogenization
a part of the phylogeny that depicts different taxa
branch
a group of species that share a single common ancestor node on a phylogeny
clade
two or more species “hidden” under a single species name
cryptic species
of a location: poor, or low, in biological diversity
depauperate
a species found only in a restricted set of locations or habitat types and nowhere else
endemic species
a measure of the diversity of species’ characteristics or functional roles of species within a community; the sum of the branch lengths of a functional diversity dendrogram
functional diversity (FD)
a two dimensional visualization of the relationships among species in terms of their functional traits; uses root, nodes, and branch lengths in a fashion analogous to a phylogeneic tree
functional diversity dendrogram
a measure of functional diversity that represents the proportion of individuals within each functional group across a functional dendrogram
functional evenness
the number of different functional traits present in a community
functional richness
a formal way of saying that often many names are used to refer to the same species
synonymy
the closest evolutionary relative of a species depicted in a phylogeny
sister species
a quantitative combination of both species evenness and richness that produces a single diversity measure
Shannon-Wiener diversity index (H)
a point of branching within a phylogeny
node
not geared for longlife or parental care, fast reproducing species
r-selected
if we kill a bunch of whales, it will take a LONG time for them to come/reach carrying capacity again, this makes them_____ seleteced
K selected
what takes longer primary succession or secondary succession
primary succession (start from nothin)
the final, stable stage of ecological succession in an ecosystem, where the composition of species remains relatively unchanged over time unless disrupted by significant environmental changes or disturbances.
climax community
low levels of disturbances is better for what kinds of species
K-selected species
high levels of disturbances is better for what kinds of species
r-selected species
occurs when a larger perturbation is needed to shift the system from one stable equilibrium into another than the other way round
hysteresis
the destructive use of animals, plants, and their products for various consumptive (ex. food, medicine) and non-consumptive (ex. trophy hunting) purposes
exploitation or harvesting
harvesting wild organisms at rates that are faster than the rates at which they can recover
overexploitation or overharvesting
refers to situations where individuals or populations that are initially well-adapted to a particular environment experience reduced fitness or survival due to changes in that environment or other factors.
decline of the fittest
ex. fish sizes getting smaller
ex. elephant trunks getting smaller
a species that is:
1. present in a location where it did not evolve
2. was moved there via human action
many cause little to no harm and many have been beneficial to human societies
non-native species
a species that is:
1. present in a location where it did not evolve
2. was moved there via human action
3. has spread in its new location, producing negative impacts on the environment, human heath, or economic systems
invasive species
refers to the process by which ecosystems across different regions become increasingly similar in terms of species composition, structure, and function. This often results in a loss of biodiversity, uniqueness, and ecological distinctiveness in different areas.
homogenization of ecosystems
ecological concepts describing how species’ geographic distributions change over time often in response to envionrmental, biological, or anthropogenic factors
range shifts, range contractions, range expansions
the movement of a species’ geographic range in response to environmental changes, such as climate change, habitat alterantion or other things
range shifts
species relocate to areas with more favorable conditions for survival and reproduction
often involves movement toward higher latitudes, elevations, or deeper ocean depths due to warming temperatures
ex. polar bears moving further north as Arctic ice melts (latitudinal shift)
R0 > = 1
species can establish
R0 <1
species goes extinct
higher biodiversity leads to reduced disease
dilution effect
