GES 1000: Environmental Systems: Climate and Vegetation Spring semester 2021
Lab #9: Biomes
1.) What biome is Colorado Springs situated in?
2.) What is the dominant climate associated with each of the following biomes?
Biome Climate
Tropical rain forest
Tropical deciduous forest
Tropical savanna
Desert
Sclerophyllous woodland
Temperate rain forest
Boreal forest
Tundra
3.) What accounts for the major biomes in the United States? Refer to the map in Figure
11-22 on pages 322-323 of the textbook.
4.) The temperate grassland biome in North America stretches from the United StatesMexican border in Texas to central Saskatchewan. What explains the eastern boundary
of the temperate grassland? In other words, what prevents the biome from occurring
further east?
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5.) South-central California is in the sclerophyllous woodland biome. A similar type of
vegetation exists around the Mediterranean Sea. What is an explanation for seeing the
same biomes in two widely separated continents?
6.) The diagram below shows the biomass distribution of vegetation in five biomes.
Which of the two biomes listed have the greatest biomass percentages below ground?
7.) On page 3 is a table with typical summer temperatures as you go up in the
atmosphere and as you go underneath the ground surface in an Arizona desert biome. At
which points are both the highest and lowest temperatures recorded?
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Altitude in centimeters Temp. (°C) at sunrise Temp. (°C) at mid-afternoon
200 13.5 43.0
150 12.5 43.0
100 12.0 44.0
50 11.5 46.0
5 11.0 49.0
0 11.0 73.0
-3 23.0 51.0
-5 24.0 42.0
-20 32.0 30.0
-50 28.0 28.0
-100 28.0 28.0
-150 28.0 28.0
-200 27.0 27.0
8.) In mid-afternoon why is the surface temperature so much higher than the temperature
at a height of 200 cm?
9.) Besides moisture deficits, what other environmental factors must desert plants and
animals adapt to?
10.) Why are desert plants often widely spaced?
11.) As one moves from east to west across the North American grasslands what happens
to the height of the grasses? Why
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12.) Why can grass withstand fire?
13.) The diagram below is a representation of the solar radiation striking the forest floor
of a temperate deciduous forest in southern Illinois. At what time of the year is solar
radiation striking the forest floor the greatest?
14.) Why are there two main “peaks” of solar radiation at the forest floor in the figure
from question 13?
15.) An important feature of the tundra biome is a subsurface of permanently frozen
ground, called permafrost. The layer of soil above the permafrost (the active layer) is
frozen during the winter but thaws during the summer season. What determines how
deep the active layer can become?
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Net primary production (NPP) is the amount of new living plant tissue gained by
growth, less the amount lost through death or relocation, per unit area, per unit interval of
time. NPP is often measured as the total weight of new material in all living things,
called plant biomass, produced annually within a square meter area over the course of a
year (g m-2
yr-1
). NPP is an important index of how well vegetation lives within the
ecological community of a place.
Plant growth is sensitive to two climatic variables, temperature and precipitation,
both of which affect evapotranspiration. Potential evapotranspiration (PE) is the moisture
that could be yielded to the atmosphere if the water supply was limitless, and is solely a
function of temperature. Actual evapotranspiration (AE) represents the amount of
moisture actually yielded to the atmosphere, and is limited by both temperature and
moisture availability. If conditions are both hot and wet, AE will be high. If conditions
are either cold or dry, AE will be low. Since AE exerts a genuine control over plant
growth, AE may be used to estimate NPP as shown in the graph below:
The equation for the line in the graph below is NPP = (2.29AE) – 366.8, and this
equation can be used to estimate the NPP of a place as long as you have the value for AE.
This equation was developed based on direct measurement of AE and NPP in a swamp in
Florida.
16.) Some tropical rainforests have an annual AE of 1900 mm. What would be their
estimated NPP?
17.) Some deserts have an annual AE of only 80 mm. What would be their estimated
NPP?
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18.) Some polar areas have an annual AE of only 150 mm. What would be their
estimated NPP?
19.) Please complete the NPP column for the table below.
Site Location Annual AE
(mm)
Annual NPP
(g m-2
yr-1
)
Green Bay,
Wisconsin
45ºN, 88ºW 504
Dryden, Ontario 50ºN, 93ºW 424
New Orleans,
Louisiana
30ºN, 90ºW 1008
Lamar, Colorado 38ºN, 103ºW 374
Painted Desert,
Arizona
36ºN, 112ºW 240
20.) The AE:NPP relationship in the graph on page 5 and in the equation derives from
direct measurements. Negative NPP values mean that a net loss of vegetation should
normally occur every year. If so, no vegetation should exist at all after only a few years,
yet there is vegetation in most deserts and polar areas. How do you explain the apparent
misprediction? (Hint: Where was the source of the data from the graph on page 5?)
Sample Solution
