conservation biology exam 2

invasive species

a species with such high abundance it affects other species, habitats or ecosystems

introduced/exoic/alien

non-native species

naturalized

an introduced species that has established in a new environment

patterns of species introductions

more invasive species in North America, Australia, and South Africa. Islands are hot spots for invasions. The naturalized species accumulation curve is steeper for non-native plants in North America.

accidental marine invasers

from ballast water from ships

accidental fresh water invaders

aquaculture escapes, hitch hikers

accidental terrestrial invaders

from packing material, commercial and individual travel

intentional introductions

• aquaculture, horticulture, agriculture for food, resources, ecological function, sport, or aesthetics

• biological control: introduced to control another organism (can backfire and becomes invasive)

characteristics of invasive species

high and earlier reproductive rates, large clutch size, few predators, large range, easy dispersal, successful in disturbed environments, and invasive in other areas

enemy release hypothesis

in the absence of home environment predators, invasive populations grow unchecked

naturalization hypothesis

Introduced species are less likely to naturalize/establish in a new ecosystem if they are closely related to native species. This is because closely related species often have similar ecological niches, leading to intense competition for resources or increased susceptibility to native predators and diseases, which hinders their establishment

Novel Weapons Hypothesis

invasive plants have chemicals that effect growth of naive plants reducing the competition for resources

biotic resistance hypothesis

diverse native communities are more resistant to invasion by non-native species than less diverse communities

empty niche hypothesis

invasive species are successful because they can exploit unused or "empty" ecological niches in a new environment, meaning they find resources or spaces not utilized by native species

biotic acceptance hypothesis

environments that can support a large number of native species are also more likely to be invaded by a large number of exotic species. This is because the same favorable abiotic conditions that promote high native diversity also provide the necessary resources and climate for non-native species to thrive

direct impact of invasive species

parasitism and predation

indirect impact of invasive species

competition for resources, disease transmission, changes to environments, and changes in species interactions

consequences of invasions

• extinction of native taxa

• changes in species richness

• decreases in beta diversity

• hybridization and loss of unique genotypes

• changes in ecosystem processes

positive impacts of invaders

can provide food, shelter, ecosystem services, replacements for extirpated species

invasion curve

model that shows how costs management success and area invaded change over time as invasive species spread. As a non-native species becomes more established over time, the effort and associated costs of addressing it escalate exponentially

global climate change

evidence: increased atmospheric green house gases, extreme of natural disasters rate of temperature change, rate of ice cap melts, increased radiation, sea levels, ocean acidity

weather

short term patterns of temperature, precipitation, and storms

climate

long-term patterns of average temperatures, precipitations, and extreme weather events

natural sources of CO2

decomposition, respiration, release from amrine ecosystems

anthropogenic sources of CO2

burning fossil fuels, deforestation, cement production

the keeling curve

a graph showing the long-term, steady increase in atmospheric carbon dioxide concentration, with a visible annual cycle caused by seasonal plant growth. It is one of the most significant pieces of evidence for human impact on the climate, as the overall upward trend is driven by fossil fuel burning and deforestation

global temperature change patterns

mean global temperatures are up by 1.09C and have risen >4C. the poles are experiencing much more rapid warming. past 10 summers have been hottest ever

global change in oceans patterns

increase in average ocean temperature, loss of arctic sea ice, sea levels rising, pH levels decreasing (more acidic)

IPCC Predictions

best case scenario global temperature will rise more than 1.5C above pre-industrial levels between 2030-2052

biological effects of climate change

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• impacts on all levels of biological organization 

• species are adapting to climate change, but not those with long generation times (etc...)

• temperature variations: changes in species abundance, but it depends on the species

• increase in primary productivity

species range shifts

species distributions are determined by environmental tolerance, resource requirements, dispersal, species interactions

in response to change, a species can: move, adapt, or die> most common response is range shifts

changes in phenology

iming of biological events. mostly temperature regulated- significant shift in phenological events. (bud bursting, flowering, mating, migration, emergence from hibernation)

species interactions

phenological mismatch- disconnect between life cycle timings of interacting species, often caused by different responses to environmental cues (flower timing not matching pollinators)

pest outbreaks- frequency severity and size have increased

effects on ecosystem services

fresh water availability, food production, coral reef bleaching

permafrost thaw

causes things to start leaching into lakes, changes composition, bacterial groups plumet, shift from autotrophs to heterotrophs

small populations

losing a few individuals can make a big difference, more vulnerable to extinction

environmental stochasticity

fluctuations in temperature, rainfall, and catastrophes affect survival and reproduction.

density independent- small and big both affected

but smaller populations may have more problems from being reduced further

allee effects

a phenomenon where a population's per capita growth rate increases with population density, meaning it has a positive correlation between individual fitness and population size. This can cause a population to decline or go extinct if its numbers fall below a certain threshold, because at low densities, individuals may struggle to find mates, cooperate, or defend themselves.

effect population (Ne)

the number of individuals in an idealized population that would experience the same rate of genetic drift as the actual population (typically count number of breeding individuals)

N does not equal Ne

Unequal sex ratio: If there are many more males than females or vice versa, the Newill be smaller than the total population size.

Unequal reproductive success: If only a few individuals have most of the offspring, the genetic contribution to the next generation is limited, lowering Ne.

Variation in Population Size/Population bottlenecks: A temporary reduction in population size can significantly decrease Ne and genetic diversity

Overlapping generations: If parents and offspring coexist, it can affect the rate of genetic drift.

smaller populations and genetic variation

• smaller populations have less genetic variation than large ones

• increased effects of genetic drift

• increased probability of inbreeding

• reduced heterozygosity

• reduced evolutionary flexibility, less opportunity for selection

census

complete count of individuals present in an area

only for organisms that fall into discrete categories

survey

repeatable sampling to estimate abundance or density of a species or community

for species with large populations or large range

for communities in different locations

demographic study

requires a specific approach; follow specific individuals and collect data

quadrats and transects

quantify organisms in a known area to estimate relative density of a larger area

great for sessile or slow moving organisms

only works well with replication

capture-mark-recapture

track the survival of individual animals overtime

assumptions:

• Mark has no effect on survival/rate of recapturing and doesn’t fall off

• marked individuals are representitive of all individuals representative

distinguishing marks

some species have phenotypes so unique they can be used to identify individuals

track individuals over time, can be done through photos or videos

observations

Typically not used to track individuals

can provide estimates of a population size

direct- aerial surveys

indirect- vocalizations, scat, footprints, nests, tracks

eDNA

collected from experimental samples, DNA left behind by organisms in forms of feces, skin cells, hair

can identify who was present in an area and how long

can identify many species from one sample

cons: samples degrade, only effective for certain sample types, may still need other samping methods

citizen science

public participation in scientific research to increase scientific knowledge, where individuals voluntarily contribute to projects by collecting and analyzing data

sampling errors

mistakes in location/ data collecting/ methods

count same individuals twice, identifying species incorrectly

sampling bias

a systematic error that occurs when a research sample is not representative of the larger population

sampling in areas that have proportionally more less individuals due to habitat heterogeneity

strict nature reserve

strictly prohibited ares set aside, human visitation/use/impacts controlled and limited

wilderness area

large unmodified (or slightly) areas retaining natural character and influence without permanent or significant human habitation

national park

protect large-scale ecological processes and complement of species and ecosystem characteristics, visitor opportunities

natural monument

landform, sea mount, submarine cavern, geological feature,

small and high visitor value

habitat/species management area

protect species or habitat, many have regular and active intervention to address requirements (but not all)

protected land/seascape

interaction of people and nature has produced an area of distant character and value, safe guard integrity of interaction

protected area with sustainable use

conserves ecosystems and habitats with associated cultural values and traditional natural resource management

low level and nonindustrial use of natra resources

land trusts

allow private land owners to contribute to protection of habitat or species

land is privately owned but activities are restricted to protect biodiversity

effectiveness of protected areas

conditions of areas peripheral to protected areas affect their effectiveness

preserve natural vegetation

strong edge effects

general positive impacts on biodiversity, taxa, marine areas, biomass

SLOSS

single large area or several small areas

single large better

(most times in general better than smaller)

when large area contains more species than smaller one, organisms require a large range, edge effects can be minimized

several small better

when habitat is heterogenous, unique communities inhabit small areas, geographical limitations on creating single large

metapopulations

studies how regional groups of interconnected, but separate, populations survive in fragmented habitats through a balance of local extinctions and colonizations. This field is crucial for conservation because it uses concepts like dispersal, immigration, and colonization to understand how species persistence is affected by habitat fragmentation, patch size, and isolation. A metapopulation can be made up of local populations with varying stability, such as a large, stable "source" population that provides individuals to more isolated, less stable "satellite" populations.

habitat connectivity

the degree to which wildlife can move between different patches of habitat, which is essential for their survival, reproduction, and genetic diversity. It is threatened by development, habitat fragmentation, and climate change, but can be improved through measures like establishing wildlife corridors and building wildlife crossings over roads