ecology exam 2
when is compensation point reached?
NPP=0 and GPP=R
why do scientists use direct measurements to study past and present climates?
analyze air samples to detect the changes in co2 emissions over time
which human activities contribute the most to GHG emissions and to climate change?
burning of fossil fuels, deforestation, and agriculture
How are biomes classified?
by the predominant plant types and climate
how do plants at the bottom of the ocean get energy?
chemosynthesis
describe the tundra
cold and dry, short growing seasons, low precipitation
describe the condition of a La Niña?
cooler than average sea surface temps, barometric pressure is higher than normal, flooding occurs in Australia
what are the effects of ocean acidification?
decreasing ph and increased levels of carbonic acid cause shells to dissolve and harm the coral reefs
Describe the temperate deciduous forest.
distinct seasons and frost, moderately high precipitation, moderate temperature
describe deserts
dry and sparse plant growth, low precipitation, and high and low temps
when does the compensation point take place?
early in the morning and late in the day
what are decomposers?
eat dead organics and convert them into inorganic
What are detritivores?
eat partially decomposed organics
describe the difference between global warming and global climate change
global warming only discusses the increase in average surface temps. global climate change captures the changes in precipitation, temp, etc
why do scientists use proxy indicators?
is the examination and dating of ice cores. measure the amount of gas trapped in the gas bubbles
why is visible light the only form of light that can drive photosynthesis?
it has just the right amount of energy to allow molecules to chemically bond together
what is the average rainfall in deserts?
less than 25 cm per year
what are the gases released from thawing permafrost?
methane and carbon dioxide
under what conditions does GPP=0
no visible light
what kind of plants and animals are found in temperate deciduous forests?
oaks, maples, beech birds, deer, bears, and insects
What causes coral bleaching?
ocean warming
what enzyme is present in C3 plants?
rubisco
what changes in climate are taking place?
some areas are getting wetter and others are getting drier. More severe hurricanes, droughts, and thunderstorms.
what is the main job of the C4 pathway?
stock up on CO2
what is the biome of North Carolina?
temperate deciduous forest
what is the best explanation for the highly productive waters and rich food webs that typically reside in the eastern Pacific Ocean off the coast of Peru?
the Humboldt Current delivers nutrients to the surface waters. this allows phytoplankton to reproduce and provide an abundance of food for zooplankton and higher levels of the food chains
When plants reach their compensation points, the amount of glucose produced by photosynthesis (GPP) is exactly equal to
the amount of glucose consumed by cellular respiration
what is a plant's compensation point?
the level of light intensity where photosynthesis and respiration are balanced
What is ocean acidification?
the ocean absorbs co2 and the co2 alters the ph by 0.1 ph units.
what conditions take place in an El Niño?
the water is warmer than normal due to no upwelling. warm water moves from the west to the east. this leads to lower productivity and lowers barometric pressure over eastern pacific
describe the saturation points of shade plants
they are saturated at lower levels of sunlight
what do El Niño and la Ninas affect?
they both affect the jet streams, which in turn affect the climate in North America
what does it mean if a plant has met their saturation points?
they have reached their max rate of photosynthesis and these rates can no longer increase
what produces the different seasons?
tilt of the planet and rotation around the sun
what happens in an El Niño?
trade winds could stop blowing or start blowing in the opposite direction
how does deforestation contribute to climate change?
trees capture co2 for decades or centuries which means there is more co2 in the atmosphere
what causes different climates?
uneven heating of the earth
what influences climatic variations?
uneven heating of the earth, latitude, and nearness to the oceans and mountains, and the elevation
what are the neutral conditions of ENSO?
upwelling occurs, trade winds blow westwards, and barometric pressure over Australia is low
describe tropical rainforests
warm, wet, and biodiverse, high precipitation, high temps, very productive
what is the most abundant greenhouse gas in the lower atmosphere?
water
what is the role of water in climate change?
water traps heat which ultimately leads to more water being evaporated and more heat being trapped
how does El Niño effect the US?
wetter in the west and Southeast regions. winters are warmer in the north
Why is upwelling important?
without it the water would not have nutrients and therefore the food web would fail
what is upwelling?
The rising of cold water from deeper layers to replace warmer surface water
what does NPP equal at the compenasation point?
0
how often does an El Niño take place?
2-7 years
which pathway makes sugars?
C3
which plants are completely susceptible to photorespiration?
C3
how are C3 and C4 separated in CAM plants?
C3 in the day and C4 at night
what plants have the C3 pathway?
C3 plants, C4 plants, and CAM plants
which group of plants are somewhat susceptible to photorespiration?
C4
which group of plants separates the C3 and C4 pathways into two different sets of photosynthetic cells?
C4 plants
which plants are not susceptible to photorespiration?
CAM
what is the most important greenhouse gas as caused by human activity?
CO2
what causes ocean acidification?
CO2 diffusing from the atmosphere into the ocean
Which environmental conditions in the eastern tropical Pacific are associated with a La Nina?
The barometric pressure becomes higher than average, and sea surface temperatures become cooler than average.