Unit 2: Biodiversity Flashcards
Ecosystem diversity
the number of diff. habitats available in
a given area
Species diversity
the number of diff. species in an ecosystem and the balance or evenness of the pop. sizes of all species in
the ecosystem
Richness
Richness (r) is just the total number of different
species found in an ecosystem
Genetic diversity
how different the genes are of individuals
within a population (group of the same species
Higher biodiversity = _______ ecosystem/
population health
Higher biodiversity = higher ecosystem/
population health
Evenness
Evenness is a measure of how all of the individual
organisms in an ecosystem are balanced between
the different species
Species
A group of organisms that is distinct form other groups in its
morphology (body form and structure), behavior, or biochemical properties.
Species must produce fertile offspring
Speciation
The evolution of new species
Background extinction rate
The average rate at which species become
extinct over the long term.
Should be 1 species per million per year.
Bottleneck Event
An env. disturbance (natural disaster/human hab.
destruction) that drastically reduces pop. size & kills
organisms regardless of their genome
Higher species diversity = ______ ecosystem resilience
higher
Restoration ecology
Restoration ecology The study and implementation of restoring damaged ecosystem
Provisioning Service
Goods taken directly
from ecosystems or
made from nat.
resources (wood,
paper, food)
Regulating
Nat. ecosystems
regulate climate/air
quality, reducing
storm damage &
healthcare costs
Trees in a forest sequester (store) CO2 through photosynthesis which
reduces rate of climate change & lessens damage caused by rising sea
level & reduces crop failure from drought
ἽἽ
● Trees filter air by absorbing air pollutants which reduces health care costs
for treating diseases like asthma and bronchitis
● Wetland plant roots filter pollutants, leading to cleaner groundwater that
we don’t have to pay as much to purify with expensive water treatment
plants
Supporting
Services that support
all of the other
services.
Habitat and genertic
diversity
Natural ecosystems support processes that support all the others.
Providing living spaces for plants or animals and maintaining a
diversity of plants and animals, are ‘supporting services’ and the
basis of all ecosystems and their services.
Examples
● Habitatats for species
ἽἽ
● Maintenance of Genetic biodiversity
️
Cultural
Money generate by
recreation (parks,
camping, tours) or
scientific knowledge
Examples
● Beautiful landscapes draw tourists who pay to enter parks, spend
money at local stores/restaurants, or camping fees
ἽἽ
● Fishermen pay for fishing licenses to catch fish in clean rivers
Disrupted by deforestation,
pollution, urbanization
ἽἽ
● Scientists learn about plant compounds that can lead to creation
of new medicines which are sold for profit
Ecosystem services
Goods that come from natural resources or services/functions that
ecosystems carry out that have measurable economic/financial
value to humans
How are Provisioning services interupted?
Disrupted by overharvesting, water pollution,
clearing land for ag/urbanization
ἽἽ
How are cultural services disrupted?
disrupted by deforestation,
pollution, urbanization
ἽἽ
Island Biography
Study of ecological relationships & community structure on islands
What are the two rules of Island Biography
The larger the island, the greater the ecosystem diversity
● Greater ecosystem diversity = more food & hab. resources
● More niches, or “roles” organisms can play in the ecosystem
Islands closer to the “mainland” support more species
Island Biogeography
● Easier for colonizing organisms to get to island
from mainland
● More colonizing organisms = more genetic
diversity in new pop.
Natural selection
Natural selection: organisms that are better adapted to their env. survive
and reproduce more offspring
Selective pressure/force
Selective pressure/force: the
environmental condition that kills
individuals without the adaptation
Predation (hawk) = selective
pressure
Range of tolerance
Range of conditions such as temperature, salinity, pH, or sunlight
that an organism can endure before injury or death
Optimal range
Optimal range: range where organisms survive, grow, and reproduce
Zone of physiological stress
Zone of physiological stress: range where organisms survive, but experience
some stress such as infertility, lack of growth, decreased activity, etc
Zone of intolerance
Zone of intolerance:
range where the
organism will die
Ex: thermal shock,
suffocation, lack of
food/water/oxygen
Periodic disturbance
Periodic: occurs with regular frequency (ex: dry-wet seasons
Episodic disturbance
Episodic: occasional events with irregular frequency (ex:
hurricanes, droughts, fires
Random disturbance
Random: no regular frequency (volcanoes, earthquakes,
and asteroids)
ἽἽ
ἽἽ
Intermediate Disturbance Hypothesis
Intermediate Disturbance Hypothesis
The highest diversity of species in an ecosystem is
maintained by a level of disturbance intermediate between
frequent and rare disturbance.
If disturbance is frequent the succession may fail to develop
beyond the pioneer phase.
If disturbance is rare, the climax will be established and
diversity reduced according to the competitive exclusion
principle
Ex. Fire
Primary Succession
Primary Succession: starts from bare rock in an area with no previous soil formation
Moss & lichen spores carried by the wind grow directly on rocks, breaking them down to form soil
Secondary Succession
Secondary Succession: starts from already established soil, in an area where a disturbance (fire/tornado/human land clearing) cleared out the majority of plant life
Grasses, sedges, wildflowers, and berry bushes have seeds dispersed by wind or animal droppings
Invasive Species to know
Emerald Ash Borer
Spread by wood packing materials of ships/planes & fire wood
Cane Toad
Introduced to eat cane beetles causing sugarcane crop loss in Australia
Became invasive due to huge appetite
Drove declines in other amphibians and small reptiles
Pythons (FL)
Brought to Florida as pets, released into wild by owners
Decimated mammal populations in Everglades ~90-95%
Aggressive hunters with no natural predators
Anrthopogenic activties
Poaching
Invasives
Climate change
Special food/needs
⛰️ CITES:
⛰️ CITES: International agreement for countries to set up agencies to monitor import and export of endangered species (as specified by IUCN Red List)
⛰️ Endangered Species Act:
⛰️ Endangered Species Act: US law giving USFWS power to designate species as endangered or threatened, monitor trade, and purchase land critical to these species’ habitats
Specialists
Less likely to move to new habitat
Less likely to adapt to new conditions
Disadvantaged by rapidly changing habitat conditions
Generalists
More likely to move to new habitat
More likely to adapt to new conditions
Advantaged by rapidly changing habitat conditions
