Biology 315 Lecture Exam 1
Answers to most of the questions on this exam can each be answered in a single short paragraph. The questions should be answered in the order presented. Answers will be evaluated on the basis of accuracy, completeness, logic, conciseness, synthesis of information, and integration of details with the big picture. Partial credit may be given for answers that are partially correct, show internally consistent logic, or are at least imaginative. Conversely, a technically correct but trivial answer will receive less than full credit. Well-constructed, complete sentences are expected. Answers with serious grammatical and spelling errors or very poor handwriting may result in lowering of the grade.
1. High density, nutrient rich, saline waters are episodically flowing onto a salt marsh and coral reef. Considering short and long term time frames describe both:
a. the expected impact on marsh diversity.
b. the expected impact on coral diversity.
2. The Coast Range in the Pacific Northwest has been vaporized by the Borg . Describe the expected influences on climate, tree species diversity, and relative proportions of C3 and C4 plants inland from the range.
3.The following is the annual nutrient budgets of Ca2+ and Mg2+ at Hubbard Brook in (kg*ha-1yr-1)
|
Ca |
Mg |
|
|
Input |
2.6 |
0.7 |
|
Output |
11.8 |
2.9 |
There are 400,000 kg per ha of calcium and 11, 000 kg per ha of Mg in the watershed. What is happening to cations in this watershed. Propose a possible cause.Which cation would you expect to be most sensitive to an equal change in flux? In the time frame of 104 years would you expect climatic or biological factors to have a greater influence on these fluxes.
4.
The current forest composition on Simple Island is defined by the state vector:1. white oak 30
2. red maple 70
The 50 year transition probabilities are provided in the from column to row transition matrix:
|
1 |
2 |
||
|
1 |
.50 |
.70 |
|
|
2 |
.50 |
.30 |
Provide the expected state vectors for 50 years and 100 years in the future:
Is this system at equilibrium?
What is the probability of transition from white oak to red maple?
5. An adjacency matrix representing the direct predation interactions of 3 species is provided below. Show the indirect interactions of length 2 observed in this system.
|
1 |
2 |
3 |
|
|
1 |
0 |
1 |
1 |
|
2 |
1 |
0 |
0 |
|
3 |
0 |
1 |
0 |
6. Cotton mouse weight is normally distributed. Observation has caused you to suspect that cotton mice that live in forests weigh less than cotton mice that live in old fields. State a hypothesis and a null hypothesis regarding your observation. Design a field study to test your hypothesis. State the statistical test that you would choose to test the hypothesis. State how you would interpret the results of your test.
7. Describe influences of increased eccentricity of the earth's orbit on climate, shadows, and tree canopy structure.