biodiversity2 probs
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II. Biodiversity – The Problems
Copyright Richard S. Feldman, Ph.D.
Extinction
• Natural and ongoing
– Fossil record
– Background rates
• 1 terrestrial vertebrate species per century
– Local regionalnationalglobal
• So why be concerned?
Concept:
The loss of biodiversity is widespread
and accelerating
–multiple causes
–dire consequences
Endangered and threatened species
a wide
range of
taxa
Decreases "in biodiversity due to human
activities were more rapid in the past 50 years
than at any time in human history…"
Millennium Ecosystem Assessment, 2005
Worldwide threats with extinction
among vertebrates:
• 12% of bird species
• 21% of fish species
• 26% of mammals*
– 50% of primates
• > 33% of amphibians
– 25-45,000 times the background extinction rate
(Center for Biological Diversity, 2015
* IUCN Red List, 2015)
Red List Index for bird species in biogeographic regions
(Birdlife, 2007)
www.ec.gc.ca
Mammals threatened with extinction
April 2015; data from IUCN Red List
and the World Bank
/
http://www.sciencealert.com/this-map-shows-where-
the-most-threatened-mammals-are-in-the-world
Native species extinctions in the U.S.
Presumed extinct: loss of last known individuals is documented;
possibly extinct: no recent documentation of existence.(Stein et al.)
Percent of species at risk of extinction.
Includes critically imperiled, imperiled & vulnerable species From: Stein et al.
Multiple causes
1. Habitat Loss
Concept:
As species lose their habitats, their chances of
survival in the wild are greatly reduced.
http://lal.cas.psu.edu/Research/Images/sprawlComp.jpg
nksandeep.wordpress.com
Terrestrial:
conversion of vast areas of forest,
grass and shrub lands, and wetlands
for agriculture and urbanization
Freshwater:
extensive alterations of rivers,
streams and lakes; wetlands
drained and filled
Loss of tropical rainforests
estimated
original
2010
Amazon tropical rain forest
~20% cut
Amazon
http://rainforests.mongabay.com/amazon/amazon_destruction.html
roads are the critical catalyst for
deforestation
http://rainforests.mongabay.com/amazon/amazon_destruction.html
Primary causes of Amazon
deforestation
1. relocation of urban population
2. government control almost nonexistent
3. cleared areas often productive for only a
year or two (related to TRF paradox)
4. soybean exports
5. cattle ranches (Fig. 6.17).
Fig. 6.17. Increase in gross deforestation (1990-2001) and cattle herd size
(1990-2002) in the Amazon. Each point represents a Brazilian state.
Amazon cattle
• large export market of inexpensive beef
• powerful sector in Brazil
– overrides efforts to reduce deforestation.
– improvements during 2005-2009, led by former
Pres. da Silva,
• cutting limits on farms, enforcement improved
– however, counterbalanced by recent influx of
small landowners – slash & burn
Regional US example:
Karner blue butterfly
Federally & NYS listed endangered species
prairieecosystems.pbwiki.com/Endangered+Karne...
Karner blue
• original range - Maine to Minnesota
– Specializes feeding upon lupine
• Fire-dependent plant species
(www.fs.fed.us/r10/tongass/districts/petersburg/images/lupine.jpg)
• NY: one population in Albany Pine Bush
– 10,000 ha reduced to 1000 ha
– sprawl - cities and suburbs spreading outward
2. Species Invasions
Concept:
Species not native to an area can suppress or
eliminate native species decreased biodiversity.
: charmeck.org/stormwater/PollutionPrevention/Pages/InvasivePlants.aspx myanimalblog.wordpress.com/.../yellow-mongoose/
kudzu mongoose
Introduced species, non-native,
aliens, and exotics
• Synonymous terms
• Species that arrived recently
U.S. ~ 50,000 alien species
• costs $137 billon annually from damage,
losses and control of them.
Subcategory:
highly invasive species
• well-adapted to the physical conditions
• increase rapidly over time and space
• exclude many native species from their
habitats, via:
– competition
– predation
– herbivory
– infection & parasitism
Japanese knotweed in Fern Tor,
Marist College
Intentional introductions –
examples?
• Gardening/landscaping
• Farming
• Pest control
• Forestry
• Aquaculture
Accidental introductions – how?
• more movement of people and goods
between biomes and countries
• crates
• soil
• ballast water
Zebra mussels
• present in
Hudson River
and other NY
freshwaters
Z. mussels
• adults grow on any hard surface
– man-made
– natural – including on other species
• loss of food and habitat for other species
– native mussels threatened
• ~$100 million damage/yr related to control.
Nile perch in Lake Victoria, Africa
• intentional introductions
• voracious predators
• eliminated much of the incredible diversity
in 30 years
vs. ~750,000 years to evolve
www.african-angler.co.uk/fishing.html
Hawaii's native birds
• 1893 – 102 native endemic species
• now - 71 extinct, 31 endangered
• Evolved without any mammalian predators
– Polynesian and European spp introduced
– https://www.youtube.com/watch?v=JLarD5vhd
Kk
Forest pests
• Asian long-horned beetle
• Emerald ash borer
3. Climate Change
Concept:
Species evolved under particular climates,
therefore as climate changes more rapidly
than they can evolve, it poses a threat to
their existence.
Past rapid climate change
• Associated with three mass extinctions in
fossil record
– Dinosaurs
• Cretaceous 65 mya
• Triassic 200 mya
• Permian 250 mya
Common effects of present
increasing temperature
• Expanded or shifted geographic ranges
– mammal, bird and insect species extending
toward the poles and up mountains
• grizzlies, pika
• earlier spring events for birds, insects &
plants
– migrations, hatchings and seed germination
• disconnection of ecological relationships
– winter moth caterpillars & English oak
Rising winter & night-time
temperatures
• Increased survival of forest insect pests and
tree pathogens
/
www.fs.fed.us/.../whitebark_pine/assessment.htm
Mountain pine beetle damage in
Rocky Mountains
hflp.sdstate.edu/Pestalrt/alert805.htm
concerns?
Eastern hemlock wooly adelgid
http://na.fs.fed.us/fhp/hwa/
www.flickr.com/photos/greendestiny/177374293/
www.uri.edu/ce/factsheets/images/hemlockadelgidRAC.jpg http://cdn2-b.examiner.com/
Changing precipitation patterns
• Costa Rica's
Monteverde Cloud
Forest Preserve
Golden toad
(footage)
http://news.bbc.co.uk/1/hi/sci/tech/328776.stm
Presumed extinct
4. Overexploitation
Concept:
If individuals of a species are harvested more
quickly than they reproduce and grow, then
their populations will be suppressed or even
eliminated.
Most conspicuous examples –
terrestrial vertebrates
Birds: dodo, passenger pigeon
Mammals: primates, big cats, wolves,
bears, rhinos, elephants
Why?
Marine examples
Mammals – whales
Fish - cod, tuna, swordfish, shark
Northern bluefin tuna
http://www.worldwildlife.org/photos/northern-bluefin-tuna--2
onemoregeneration.orghttp://www.cbs.com/shows/cbs_this_morning/video/bA3DOReFqaMRG
mq4JZgXOpgX2BvWTtM2/-world-s-best-sushi-chef-gives-dire-warning/
Bycatch
– reptiles (sea turtles)
– fish (sawfish)
– mammals (dolphins)– https://www.youtube.com/watch?
v=PyGHk6zIL-Y
5. Pollution
Concept:
When habitat for a species is contaminated,
the species may suffer reduced reproduction
and growth, threatening its survival.
Pollutant types
• Excess nutrients – eutrophication
– Sequence leads to oxygen depletion in waters
– Ultimately dead zones & fish kills
www.sudburyvalleytrustees.org-
www.ecology.com-
Pollutant types
• Industrial chemicals & pesticides
– DDT
• previously threatened American bald eagle
– and related chemicals – endocrine disruptors
• Florida panther
www.zmescience.com
Distilling down the threats to
biodiversity
“The cost of doing business”
• Massive cost externalization
• Does not have to be like that … options?
– Sustainable development
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