PBIO 1000 EXAM 3 QUESTIONS WITH VERIFIED ANSWERS
Invasive species - Answers - a species that is non-native to an ecosystem under
consideration, and whose introduction causes or is likely to cause economic or
environmental harm/harm to human health.
What *societal factors* must be considered for identifying a plant as invasive for policy
& management purposes - Answers - -negative effects outweigh the positive effects or
benefits.
-this applies to both direct & indirect effects
Describe the barriers that invasive species have surmounted & how humans can
unintentionally support these invasions - Answers - -*large-scale geographical barriers-
overcoming a mountain range, oceans, similar physical barrier for movement of seeds
-*survival barriers*= adequate moister, soil ph, nutrient availability. Overcomes
competition of resources
-*establishment barriers*- needs to self sustaining. Does not not need re-introduction to
maintain population
-*dispersal & spread barriers*= must spread from original site. Relatively fast rate
-*harm & impact*= causes negative effect which outweigh any beneficial effect
Describe when domesticated/introduced plant species are considered invasive & how
this can differ from one area to another - Answers - -canadian geese & deer in North
America; causing problems but aren't considered invasive because they're
domesticated to the area
-escaped or ferel populations of formally domesticated species would be considered
"invasive" if all barriers are met (previous slide)
-ex. Cereal rye being produced on a farm is considered desirable, but feral rye on the
breaks in a different area would be considered an invasive species if barriers are met.
-species can be invasive in one part of the country but not the other; biogeographical
context
-ex. Lake trout are highly desirable in the Great Lakes where they're native, but are
considered an invasive species in Yellowstone Lake due to the various other fish
species in each lake
Describe what constitutes environmental harm by invasive species - Answers -
biologically significant decreases in native species populations, alternations to plant &
animal communities or to ecological processes that native species & other desirable
plants/animals/humans depend on for survival.
Distinguish between direct & indirect effects of invasive plant species on ecosystems -
Answers - -direct= preying & feeding on, causing or vectoring diseases, preventing from
reproducing/killing young of, out-competing for food, nutrients, nest sites, or other vital
sources, or hybridizing so frequently little of original species remains of native species.
, -indirect= decrease in a native species that may result when an invasive plant
decreases abundance of native plants that native species depends on for survival
Explain how invasive species can have negative effects on their natural or economic
sources or both; impacts of chestnut blight & European gypsy moths on deciduous
forests - Answers - -chestnut blight is a disease on North American chestnuts, non-
native fungal pathogen.
-European gypsy moth defoliates trees on millions of acres in northwestern forests;
found in 19 states & causes estimated 3.9 billion in tree losses; decreases wildlife
habitat
Direct & indirect effects on white pine blister rust on natural resources - Answers - -non-
native fungal pathogen, introduced to eastern North America in 1900 & western North
America in 1920
-spread rapidly; killing off native white, white park & limber pines (seeds are imp food
source for birds, rodents & bears)
-elimination alters forest ecosystems, eliminates wildlife forage & decreases soil
stabilization, snowmelt regulation & forest succession
Effects on property values of Asian longhorns beetles & Emerald ash borer - Answers -
-Asian longhorned beetles appeared in NY in 1996 & Chicago 1998, larvae burrow into
trees & can kill trees, infests all sorts of tree species, threat to urban & rural forests
-Emerald ash borer first detected in 2002 (US); larvae burrow under ash trees & can
potentially kill ash trees as shade, street & forest tree across US; currently found in
Michigan, Ohio & Indiana
Effects of hydrilla on ecosystems & recreational opportunities - Answers - -hydrilla forms
dense canopies at waters surface that raise surface water temperatures, change ph,
exclude light & consume oxygen; results in native fish displacement & stunted sport fish
populations
Describe the goals of the Endangered Species Act; the role of the U.S. Fish & Wildlife
Service's role in achieving these goals - Answers - -ESA protects endangered &
threatened species & their habitats by prohibiting the "take" of listed animals & the inter-
state/national trade in listed plants & animals, including their parts & products except
under a Federal Permit.
-FWS primary responsibility is for terrestrial and freshwater organisms; maintains a list
of "candidate" species; works with states, tribes, private landowners/partners & federal
agencies to carryout conservation actions
Endangered versus threatened species - Answers - -endangered= species is in danger
of extinction throughout all/ a significant portion of it's range
-threatened= species is likely to become endangered within the foreseeable future
Name 5 factors that are considered before a species is listed - Answers - 1. Damage to
or destruction of a species' habitat
Invasive species - Answers - a species that is non-native to an ecosystem under
consideration, and whose introduction causes or is likely to cause economic or
environmental harm/harm to human health.
What *societal factors* must be considered for identifying a plant as invasive for policy
& management purposes - Answers - -negative effects outweigh the positive effects or
benefits.
-this applies to both direct & indirect effects
Describe the barriers that invasive species have surmounted & how humans can
unintentionally support these invasions - Answers - -*large-scale geographical barriers-
overcoming a mountain range, oceans, similar physical barrier for movement of seeds
-*survival barriers*= adequate moister, soil ph, nutrient availability. Overcomes
competition of resources
-*establishment barriers*- needs to self sustaining. Does not not need re-introduction to
maintain population
-*dispersal & spread barriers*= must spread from original site. Relatively fast rate
-*harm & impact*= causes negative effect which outweigh any beneficial effect
Describe when domesticated/introduced plant species are considered invasive & how
this can differ from one area to another - Answers - -canadian geese & deer in North
America; causing problems but aren't considered invasive because they're
domesticated to the area
-escaped or ferel populations of formally domesticated species would be considered
"invasive" if all barriers are met (previous slide)
-ex. Cereal rye being produced on a farm is considered desirable, but feral rye on the
breaks in a different area would be considered an invasive species if barriers are met.
-species can be invasive in one part of the country but not the other; biogeographical
context
-ex. Lake trout are highly desirable in the Great Lakes where they're native, but are
considered an invasive species in Yellowstone Lake due to the various other fish
species in each lake
Describe what constitutes environmental harm by invasive species - Answers -
biologically significant decreases in native species populations, alternations to plant &
animal communities or to ecological processes that native species & other desirable
plants/animals/humans depend on for survival.
Distinguish between direct & indirect effects of invasive plant species on ecosystems -
Answers - -direct= preying & feeding on, causing or vectoring diseases, preventing from
reproducing/killing young of, out-competing for food, nutrients, nest sites, or other vital
sources, or hybridizing so frequently little of original species remains of native species.
, -indirect= decrease in a native species that may result when an invasive plant
decreases abundance of native plants that native species depends on for survival
Explain how invasive species can have negative effects on their natural or economic
sources or both; impacts of chestnut blight & European gypsy moths on deciduous
forests - Answers - -chestnut blight is a disease on North American chestnuts, non-
native fungal pathogen.
-European gypsy moth defoliates trees on millions of acres in northwestern forests;
found in 19 states & causes estimated 3.9 billion in tree losses; decreases wildlife
habitat
Direct & indirect effects on white pine blister rust on natural resources - Answers - -non-
native fungal pathogen, introduced to eastern North America in 1900 & western North
America in 1920
-spread rapidly; killing off native white, white park & limber pines (seeds are imp food
source for birds, rodents & bears)
-elimination alters forest ecosystems, eliminates wildlife forage & decreases soil
stabilization, snowmelt regulation & forest succession
Effects on property values of Asian longhorns beetles & Emerald ash borer - Answers -
-Asian longhorned beetles appeared in NY in 1996 & Chicago 1998, larvae burrow into
trees & can kill trees, infests all sorts of tree species, threat to urban & rural forests
-Emerald ash borer first detected in 2002 (US); larvae burrow under ash trees & can
potentially kill ash trees as shade, street & forest tree across US; currently found in
Michigan, Ohio & Indiana
Effects of hydrilla on ecosystems & recreational opportunities - Answers - -hydrilla forms
dense canopies at waters surface that raise surface water temperatures, change ph,
exclude light & consume oxygen; results in native fish displacement & stunted sport fish
populations
Describe the goals of the Endangered Species Act; the role of the U.S. Fish & Wildlife
Service's role in achieving these goals - Answers - -ESA protects endangered &
threatened species & their habitats by prohibiting the "take" of listed animals & the inter-
state/national trade in listed plants & animals, including their parts & products except
under a Federal Permit.
-FWS primary responsibility is for terrestrial and freshwater organisms; maintains a list
of "candidate" species; works with states, tribes, private landowners/partners & federal
agencies to carryout conservation actions
Endangered versus threatened species - Answers - -endangered= species is in danger
of extinction throughout all/ a significant portion of it's range
-threatened= species is likely to become endangered within the foreseeable future
Name 5 factors that are considered before a species is listed - Answers - 1. Damage to
or destruction of a species' habitat
