bio 112 final exam

biotic

living factors—other organisms that are part of an individual’s environment

abiotic

nonliving factors such as temperature, light, water, and nutrients

distribution of terrestrial biomes

depends on climate (temperature, precipitation, sunlight, wind)

distribution of aquatic biomes

depends on light and nutrient availability

tropical rainforest

occurs in equatorial and subequatorial regions; warm and wet year-round; broadleaf evergreen trees; vertically layered; intense competition for light; highest biodiversity; face deforestation; nutrient-poor soil; Amazon rainforest

savanna

occurs in equatorial and subequatorial regions; seasonal precipitation; warm year-round; fire-adapted grasses and forbs tolerant of seasonal drought; wildebeest and zebra, insect dominant herbivore; threatened by ranching and over poaching; controlled fires

desert

occur in bands near 30 degrees north and south of equator and in interior of continents; low precipitation highly variable; temperature varies seasonally and daily; plants adapted for heat and desiccation tolerance, water storage, reduced leaf surface; C4 or CAM photosynthesis; animals nocturnal with water conservation; reduced biodiversity through urbanization and irrigated agriculture

chaparral

occurs in midlatitude coastal regions on many continents; highly seasonable precipitation; rainy winters + dry summers; hot summer, cool fall winter and spring; shrubs, small trees, grasses and herbs, plants adapted to fire and drought; animals amphibians, birds, other reptiles, insects, mammals, browsing mammals; reduced through agriculture and urbanization

temperate broadleaf forest

occurs at midlatitudes in north hemisphere, smaller areas in chile, south africa, Australia, new zealand; lots of precipitation as rain or snow; winters at 0 degrees C and hot summers; vertical layers: closed canopy, understory trees, shrub layer, herb layer; deciduous trees in north hemisphere and evergreen eucalyptus in austrailia; mammals, birds, and insects; in n. hemisphere, many mammals hibernate and birds migrate in winter; settled by humans

coniferous forest

aka taiga, northern north America and Eurasia, largest terrestrial biome, precipitation 30-70 cm, periodic drought common, coastal forests may receive over 300 cm of annual precipitation, cold winters, summers may be hot; evergreen conifers: pine, spruce, fir, hemlock; conical tree shape to reduce branch breakage from snow; needle-like leaves reduce water loss; migratory and resident birds and large mammals: moose, brown bears, and Siberian tigers; periodic insect outbreaks kill areas; human logging

arctic tundra

covers expansive areas of the arctic, cold cold winters, with cold summers, low precipitation, permafrost present, short growing season, mosses and lichens common

alpine tundra

found at high elevations; cold, windy, little soil, no trees due to harsh climate

polar ice

extremely cold; ice-covered year-round, very little plant life; organisms highly specialized

lakes

standing freshwater; zones vary by depth and light; supports fish, algae, aquatic plants

wetlands

land saturated with water; very productive ecosystems; filter pollutants and reduce flooding

streams and rivers

flowing freshwater; oxygen-rich in fast moving sections

estuaries

where freshwater mixes with saltwater; nutrient-rich and highly productive; nursery habitat for many species

intertidal zones

area between high and low tide; organisms tolerate changing conditions; strong wave action

oceanic pelagic zone

open ocean away from shore; dominated by plankton and swimming organisms; major site of photosynthesis

coral reefs

warm shallow marine ecosystems; extremely biodiverse; built by coral animals; threatened by warming and acidification

marine benthic zone

ocean floor habitat; organisms live on or in sediment; includes deep-sea ecosystems

climate change on biome distribution

changes temp and precipitation patterns

species shift towards poles or higher elevations

melting ice reduces tundra and polar habitats

increased drought can expand deserts

coral reefs decline due to warming oceans

species richness

the number of different species in the community

relative abundance

the proportion each species represents of all individuals in the community

species diversity

the variety of organisms it includes

ecological niche

the specific set of biotic and abiotic environmental resources it uses

mutualism

—(+/+) benefits both species; in some relationships, each species depends on the other for their survival and reproduction; in others, both species can survive alone; partners may incur costs, the benefit must outweigh the cost of the partnership

ex: bees pollinating flowers

commensalism

—(+/0) individuals of one species benefits while members of the other species is neither harmed nor helped; some interactions may at times be mutualistic

ex: barnacles on whales

parasitism

—(+/-) parasite derives nourishment from another organism, its host, which is harmed in the process; many have complex life cycles involving many hosts

ex: tick feeding on dog

endoparasites

parasites that live within the body of their host

ectoparasites

parasites that live on the external surface of a host

predation

(+/-) interaction in which individual of one species—the predator—kills and eats an individual of another species—the prey; most predators have acute senses, claws, fangs, or poison, are fast and agile and/or camouflaged

ex: lion hunting zebra

herbivory

(+/-) interaction where herbivore eats parts of a plant or alga; do not usually kill the plants or algae they feed on; most invertebrates

ex: deer eating grass

competition

(-/-) occurs when individuals of different species use a resource that limits survival and reproduction of both individuals; species do not compete for resources that are not in short supply

ex: lions and cheetahs hunting for antelope

batesian mimicry

a palatable or harmless species mimics an unpalatable or harmful model

mullerian mimicry

two or more unpalatable species resemble each other; predators can learn to avoid unpalatable prey faster when they encounter more of them with a similar appearance

cryptic coloration

aka camouflage, makes prey difficult to see in their environment

energetic hypothesis

suggests that length is limited by inefficient energy transfer; only about 10% of the energy stored in organic matter at each trophic level is converted to organic matter at the next trophic level

keystone species

exert strong control on a community with their pivotal ecological roles; not usually abundant in a community

ecosystem engineers

create or dramatically alter their physical environment

ex: beavers can transform landscapes

bottom-up control

limiting nutrient supply or available of food at lower trophic levels limits the abundance of organisms at higher trophic levels

top-down control

the abundance of organisms at higher trophic levels controls the abundance of organisms at lower trophic levels

disturbance on species diversity and composition

keeps many communites from reaching equilibrium

communities constantly changing after disturbance

moderate levels of disturbance foster greater diversity than do high or low levels of disturbance

prevents one species from dominating

severe disturbance may reduce biodiversity

disturbance

an event that changes a community by removing organisms from it or altering resource availability

ecological succession

refers to the pattern of colonization and species replacement that occurs in a community following a severe disturbance

primary succession

when ecological succession begins in a virtually lifeless area; prokaryotes and protists are only life forms present; bare rock and lichens arrive first, soil gradually develops as rocks weather and organic matter accumulates as early colonizers decompose; climax community establishes after soil develops

secondary succession

involves the recolonization of an area after a major disturbance has remove most but not all of the organisms

genetic diversity

comprises genetic variation within a population and between populations

species diversity

the number of species in an ecosystem or across the biosphere

ecosystem diversity

the total of the different systems across the biosphere

minimum viable population

the minimum population size at which a species can sustain its numbers; estimated by integrating many factors, such as an estimate of how many individuals are likely to be killed by storms or other catastrophes

biodiversity hot spots

relatively small area with numerous endemic (found nowhere else) and many endangered and threatened species

ecosystem services

the processes by which natural ecosystems help sustain human life

purification of water and air

detoxification and decomposition of wastes

crop pollination, pest control, soil preservation

moderation of weather extremes and flooding

tourism

major threats to biodiversity

habitat loss, introduced species, overharvesting, global change

greenhouse gases

trap heat from sun in earth’s atmosphere

carbon dioxde

water vapor

methane

nitrous oxide

dead zones

when phytoplankton die, oxygen is depleted by their decomposers, resulting in death of aquatic animals

how to maintain biodiversity

reduce waste

recycle

conserve water and energy

protect habitats

reduce pollution

use renewable energy

conservation laws and restoration projects