Chapter 21 - Community Ecology

BIO 1334

what is a trophic cascades example

honeybees

colony collapse disorder (CCD)

first reported in 2006 but has improved in the past few years; worker bees leave queen and a few nurses behind

ecological communities

groups of interacting populations of different species living in the same area

ecological communities example

honeybees are pollinators

pollinators

transfer pollen from male to female plant structures; allows fertilization of plants to occur

pollen

small plant structures; develop into sperm

communities rely on ________

communities rely on keystone species

what percentage of angiosperms are dependent on insect pollinators

75%

keystone species

other species in an community depend on them and they hold community together; top to bottom of the food chain

what are animals of keystone species

wolves, beavers, honeybees

keystone species example

wolves ate deer that ate herbs —> changed deer behavior, birds and beavers increased —> rivers changed (more dams)

food chains

linked sequences of feeding relationships in a community; organisms categorized by whom eats whomp

producers

autotrophs that supply energy to rest of food chain

consumers

heterotrophs that eat producers

predators

organisms that feed on Stoehr organisms/prey

herbivores

predation on plants (may or may not kill plants)

carnivores

predation on animals

omnivores

predation on plants and animals

trophic levels

feeding levels based on positions in a food chain; energy is lost as it goes up - only 10% of energy makes it to the next trophic level

food webs

several interconnected food chainswh

what are the types of symbiotic relationships

parasitism, mutualism, commensalism

symbiosis

relationship where 2 organisms live in association

parasitism

one organism benefits by harming the other

parasitism example

varroa mite and bees, pinworms and humans

mutalism

both organisms benefit from

mutualism example

bees and flowers, clownfish and anemone

commensalism

one organism benefits, other is unharmed

commensalism example

bees and trees, egrets and water buffalos

what is happening to the honeybees?

parasitic varroa mite infestation, fungus, AIDS, APV, IIV, malnutrition

niche

space, environment, resources a species needs to survive and reproducewh

what happens if two niches overlap

competitive exclusion principle

competition exclusion principle

drives a competing species to extinction

colony collapse disorder

complex solution for humans for honeybees