Studied by 16 peoplebiological control
using natural predator or virus to control invasive species
bad example of biological control
Indian mongoose introduced to Hawaii to eat rats that arrived on boats but don't eat rats --> ate native bird eggs --> extinction; metal rings around trees to prevent climbing
good example of biological control
BT (bacillus thuringiensis) - bacteria that kills larva of pests (caterpillar, hematoads); safe for predatory insects
biological magnification
process by which chem substances become more concentrated at each trophic level
DDT (Dichlorodiphenyltrichloroethane)
insecticide, makes bird eggs more brittle/crack easily (ex: eggs of seabirds)
most things that are biomagnified are stored in _______, since ________ tend to be last resort for energy & aren't broken down
fat tissue, lipids
tuna & swordfish have a high concentration of ________
mercury
ozone (O3) layer
in stratosphere; absorbs UV radiation
what occured in 1985?
data collected on ozone layer showed dramatic depletion
thinning of ozone layer was caused by the release of _____
CFCs (chlorofluoro carbons)
CFC in the presence of UV light becomes _____
Cl-
Cl- in the ozone layer becomes
chloroxide
equation for circular process that led to thinning of ozone layer
Cl- + O3 = ClO + O2 ClO + ClO = 2Cl- + O2
conservation biology
attempt by scientists & governing bodies to maintain or increase biodiversity
how can humans increase biodiversity? (5)
physically remove invasive species, clean up polluted environment, spread edu. on biodiversity, create protected areas (ex: national parks), lessen carbon footprint
indicator species
species whose presence tells us something about biodiversity or health of environment
_____ are good indicator species, can only be supported by a health ecosystem
large carnivores
_____ are good indicator species, sensitive to chemicals/pollutants
amphibians
in management of conservation areas, ______ requires both prioritization & funding (3)
restoration, threatened/endangered species, removal of introduced species,
three factors needed for reserve to be successful
size
edge effect
corridors
why is size of nature preserve important?
larger size, less edge effect
edge effect
how much influence humans or other invasive species have on nature preserve
corridors
strip of natural habitat that connects separated populations; still maintains infrastructure
cowbirds
brood parasitoids that lay eggs in other birds' nests, hatchlings dominate the nest
extinction
death of every member of a species; local or global
examples of extinct species
dodo bird, Carolina parakeet, Tasmanian tiger/wolf
how do humans contribute to extinction?
humans accelerate extinction rates
causes of extinction (6)
change, in general, causes extinction; habitat loss, disease/epidemic, climate change, invasive species, overhunting, lack of resources
keystone species
species that influences survival of many other species in ecosystem; essential species in ecosystem
removal of a keystone species from a community will...
have a disproportionate effect; may collapse ecosystem (ex: honeybees, sea otters)
Note
Flashcard