Biodiversity and Conservation Biology Flashcards
species richness
the number of species in a defined area/community
one of the strongest patterns in ecology is the latitudinal diversity gradient
latitudinal diversity gradient
for most groups, there are more species at low latitudes (closer to equator) than high latitudes (closer to poles)
multiple, non-mutually excessive hypotheses
species evenness
the relative abundance of each species in a defined area/community
can be incorporated into estimates of diversity
species diversity
incorporates both richness and evenness
endemic
found in a particular area and nowhere else
species endemism
high values often in small and/or isolated habitat patches
- islands (e.g. Galapagos)
- mountains (e.g. Eastern Arc Mountains)
- isolated forests (e.g. Atlantic forest)
genetic diversity
total genetic information within a defined population, species, or community
new sequencing technology especially effective at measuring microbial and fungal diversity
- environmental sampling or metagenomics
- collect massive amounts of DNA or RNA sequences soils or water
- detect species (genomic) or functional (expressed genes) diversity
taxonomic (phylogenetic) diversity
some branches in the ToL of species rich and others are species poor
conserving species poor branches increases taxonomic diversity
-includes phylogenetic distance between species
biodiversity hotspots
areas with exceptional concentrations of endemic species and high levels of habitat lost
habitat destruction/degradation is one criteria for defining hotspots
pioneered by Norman Myers
criteria:
- at least 1500 (0.5%) of world’s 300,000 plant species as endemics
- lost 70% or more of its historic (traditional) vegetation
34 hotspots
- 2.3% land area
- > 50% of all plant species and >42% of all vertebrate species
criticisms
- focus on endemism
- focus on historic rather than current loss (Amazon, Congo, and New Guinea rainforests do not qualify)
- what about boreal and tundra biomes
Atlantic forest
variety of tropical forest ecosystems in SE Brazil
high levels of endemism
estimated 15% of historic range
habitat destruction
mostly due to human land use
-logging, dams, dredging, livestock, agriculture, mining, development
deforestation
habitat degradation
reduction in the quality of a habitat caused by human activities
use of artificial light at night and creating traffic noise
more degraded “edge” habitat
- more exposure to light and wind
- higher likelihood of invasion by weedy species
multiple factors and threats to biodiversity
habitat lost
invasive species
over-exploration
pollution
native species interactions
natural causes
climate change
loss of polar and high altitude habitats
change of coastal habitats due to sea level rise
difficulty for some species to shift ranges
increased frequency/intensity of storms and droughts
increased sea temperatures and acidification
-coral bleaching
invasive species
exotic species that grows to a large population size and compete successfully with native species
estimated 58% of extinctions in last 500 years primarily due to invasive species
mediated by global trade and travel
exotic species
non-native species introduced to a new area
overexploitation
unsustainable removal of wildlife form the environment for use by humans
major threat for marine species
hunting bushmeat
animal products
pet trade
e.g. Atlantic cod
pollution
wide variety of pollutants (e.g. industrial, pharmaceutical, pesticides, fertilizer sewage)
Atrazine
herbicide used in agriculture since 1958
2nd most common used herbicide in USA
also one of the most commonly detected pesticides in drinking water
endocrine disruptor that affects amphibian and fish larval development
feminization of male frogs
-lowered testosterone, hermaphroditism, feminized laryngeal development, suppressed mating behavior, reduced spermatogenesis, decreased fertility
use banned EU (2003)
EPA reviewed ecological risks in 2016
-levels of concern for chronic risk are often
exceeded
-run-off affects plant biodiversity away from
fields
EPA reviewed risk to humans in 2018
-was open for public comment
-risk mitigations, if any, will be
recommended in 2019
ecosystem services
direct and indirect benefits that human derive from ecosystems
- supporting
- provisioning
- regulating
- cultural
supporting services
vital functions that are necessary for the production of all other ecosystem services
- primary productivity
- nutrient recycling
- pollination
- biological control
increased biodiversity less to higher productivity
- more efficient use of resources
- facilitations
also greater resilience
resilience
a measure of how quickly a community recovers from a disturbance
resistance
a measure of the extant to which a community remains unchanged after a disturbance
provisioning services
products obtained from ecosystems
- food
- raw materials (e.g. timber, fertilizer)
- energy (e.g. biofuels, hydropower)
- genetic resources (e.g. crop improvement genes)
- medicines
regulating services
benefits form the regulation of ecosystem processes
a few examples…
- soil formation
- water purification
- flood and erosion control
- water control
- waste decomposition
cultural services
nonmaterial benefits
- recreation and tourism
- aesthetic value
- spiritual and cultural
- mental health
we demonstrate that of 5 neighborhood nature characteristics tested, vegetation cover and afternoon bird abundances were positively associated with a lower prevalence of depression, anxiety, and stress
Endangered Species Act
passed in1973
aims to protect and recover imperiled species and ecosystems
- species are proposed for listing as threatened or endangered
- thorough review process includes expert and public comments
- includes international collaboration on some foreign species
Administered by
- United States Fish and Wildlife Service (USFWS); terrestrial & freshwater
- National Oceanic and Atmospheric Administration (NOAA); marine
Protection offered has caused population sizes of
many species to increase
-38 species have been officially delisted in USA
Criticisms:
- low success rate?
- may encourage preemptive habitat destruction
advances in conservation
research demonstrate physiological effects in birds of prey
-made egg shells thinner; lowered fitness
also negative effects on human health
-endocrine disruptor, carcinogen
danger of pesticides to wildlife and humans highlighted in Rachel Carson’s book, Silent Spring
subsequent ban of DDT in 1972 and habitat restoration have caused numbers to rebound
Rachel Carson
wrote the book Silent Spring
which highlights the danger of pesticides to wildlife and humans
biodiversity
means biological diversity
DNA barcoding
the use of well-characterized gene sequences to distinguish species
ecosystem diversity
a measure of these complex factors plus interactions with the nonliving environment
it is the most difficult level of biodiversity to define and measure because the complexity of ecosystems is so vast
ecosystem function
refers to the sum of biological and chemical processes that characteristic of a given ecosystem–such as primary production, nitrogen cycling, decomposition, and carbon storage
these functions emerge from the sum of feeding, growing, moving, respiring, excreting, and decomposing processes of the interacting member organisms within their abiotic context
endangered species
a species whose numbers have decreased so drastically that it is almost certain to go extinct unless effective conservation programs are put in place
habitat fragmentation
dividing contiguous areas of natural habitats into small, isolated fragments
changes metapopulation dynamics
- patches become smaller, connectivity between patches decreases
- increased likelihood of local extinctions, particularly for top predators
Norman Myers
pioneered biodiversity hotspots
species-area relationships
used by biologists to estimate rates of extinction, given enough reasonable projections of how much habitat will be lost over a given time period
natural experiment
occurs when comparison groups are created by an unplanned, unmanipulated change in conditions
bioprospecting
the exploration of bacteria, archaea, protists, plants, fungi, and animals as novel sources of drugs or ingredients in consumer products
has benefited from the recent explosion of genetic info
sustainability
the managed use of resources at a rate only as high as the rate at which they are replaced
seed banks
long term storage facilities used to preserve valuable genetic diversity of crop plants and non-crop plants
ex situ conservation
the preservation of species in zoos, aquaria, botanical gardens, or other artificial settings
not ideal, but preferred over extinction
ex situ means out of place
wildlife corridors
strips of underdeveloped habitat that connect preserved areas
e.g. walkway under highway
ecotourism
recreational visits to wild places
will help economy profit more in the long term compared to logging
