Environmental Science 362-302 Name_______________________
EXAMINATION #3
[Note: You are given several choices for questions to answer. If you answer more than
the required number, I will only grade as many as you were supposed to answer -- any
additional answers will not be graded.]
Part I: Identification. Briefly define 5 of 6 (4 points each for a total of 20 points)
1.1 Thinning Phase
1.2 Chamaeophyte
1.3 John Curtis
1.4 Facilitation
1.5 Cation-exchange capacity
1.6 Denitrification
Part II. Short Answers. Answer 7 of 9 (6 points each for a total of 42 points).
2.1 What is meant by exogeneous vs. endogeneous disturbance regimes? How might the
frequency of the four main stages of succession differ between communities effected by
them?
2.2 The number of nitrogen-fixers in native Wisconsin grasslands has apparently fallen
over the last 50 years. How this might be the result of human alternations to the Nitrogen
cycle?
2.3 Provide at least three reasons why are tropical forest communities more species rich
than Wisconsin forests.
2.4 Graphically represent, using the theory of Island-Biogeography, what may happen to
species richness of a forest if habitat size is drastically reduced due to deforestation.
2.5 Soil communities (made primarily of small invertebrates) often have up to 8 trophic
levels, starting with the smallest decomposing bacteria and ending with the largest
predatory beetles and spiders. The above-ground communities in the exact same place
will have no more than 4 (and usually only 3) trophic levels. What differences in the
basic energetics of these communities could account for this difference?
2.6 You are given a bottle of radioactively-labeled CO2. How could you use it to
measure NPP in a grassland community? (Yes, I mean NPP here!)
2.7 Diagram how species distributions tend to change along a wet-dry environmental
gradient in the sand prairies of Illinois (where Gleason did his research) vs. the prairieforest
boundary along the Platte River near Lincoln, Nebraska (where Clements did his
research). How did these lead to different views of community structure?
2.8 Draw and label a soil profile for a typical northern Wisconsin (pine forest) and a
typical southern Wisconsin (prairie) habitat. How do they differ, and why?
2.9 Diagram the chemical processes that have allowed the Finger Lakes of central New
York (underlain by calcareous shale & limestone) to maintain constant water acidity,
even though lakes in the Adirondacks a hundred miles to the north (underlain by granite)
have had their acidity increase, even though both are being exposed to pH 4 rainwater.
Part III. Problem Sets.
1. You mark out a 1m² meter quadrat at the dunes at Point Beach State Forest. During a
given year, approximately 1.2 million kcal of sunlight strikes this area.
Using various techniques, you discover that 85,200 kcal in plant biomass is
accumulated per year in this quadrat. Living in this quadrat are isopods that have
been shown to have an ecological (production) efficiency of 25%. In this quadrat over
the course of a year, 900 kcal in isopod body mass increase and 1000 kcal in
reproduction was recorded. The amount of energy loss from feces and urine
for these isopods was determined to be 7250 kcal. The isopods are eaten by
predatory Carabid Beetles, which were found to accumulate 1504 kcal in assimilation
energy per year in the quadrat.
For this system, calculate:
NPP efficiency (2 pts)
Consumption efficiency of the isopods (5 pts)
Lindeman's efficiency between the isopods and Carabid Beetles (2 pts)
2. Following is data on species abundance for two Tamarack wet forests faunas. Using
both heterogeneity indices, determine if one has clearly greater evenness than other? If
your answer is 'no', give me some possible reasons why. (14 points)
Battle River
Beltrami County Location: 94.5240 W., 48.0325 N.
Habitat Type: Wet, acidic Tamarack-White Cedar wetland with abundant Sphagnum.
Carychium exiguum 162 Euconulus alderi 10
Gastrocopta tappaniana 27 Vertigo elatior 10
Nesovitrea electrina 19 Striatura milium 2
Punctum minutissimum 13 Vertigo nylanderi 2
Tamarack Lake 1
Clearwater County Location: 95.4492 W., 47.4363 N.
Habitat Type: Very wet Tamarack, Alder, Bog Birch swamp forest.
Carychium exiguum 45 Catinella avara 4
Nesovitrea electrina 25 Vertigo elatior 4
Gastrocopta tappaniana 10 Euconulus alderi 1
Striatura milium 7
Part V. Short Essay. Answer 1 of 2 (15 points) on back of page.
5.1 One of the great debates in conservation biology over the last 2 decades is whether
more species will be protected if a single large area is protected vs. proteceting many
smaller areas that sum to the same total size. Considering our class discussions of species
richness, give me your thoughts about this debate. In particular, suggest situations in
which each of these approaches would protect the greatest number of species, and why.
5.2 One of the greatest problems facing biodiversity currently is the threat of rapid
climate change due to global warming. Assuming for the moment that such changes will
occur, suggest strategies that might need to be taken to help maintain biodiversity in
nature reserves. Defend your suggestions using ideas we've talked about over the
semester!