FOR 274 Forest Measurements and Inventory Written Take Home Exam Instructions: This exam is comprehensive of the material covered within the Forest Resources 274 class curriculum. The first question is over general material covered in both lab and lecture, while the other questions cover material that is similar to that seen on homework's and lab exercises throughout the semester. YOU MUST DO QUESTION 1 YOU MUST DO AT LEAST 2 QUESTIONS FROM 2-4 (The top 2 scores from question 2-4 will be recorded as part of the exam grade. Extra credit will be awarded for a significant attempt of the remaining question) All equations that cannot be easily derived are provided. Calculator recommended.
1. Fundamental Forest Measurements [80 points Each person must answer this question] A. Plot Size [19 points 5-5-5-4]: i. Calculate to the nearest 1/10 th foot the radius of a 1/25 th acre circular plot. ii. Calculate to the nearest 10 cm the radius of a 1/10 hectare circular plot. iii. Describe advantages/disadvantages on why you may select a circular or a rectangular plot? iv. Name 3 commonly used tools for variable radius plots. B. Refer to the figures and calculate the total height to the nearest foot [25 points]: i. You are 50 feet away and measure AB to be 70 and then pace the length of BC as 35 feet. ii. You are standing at a horizontal distance of 66 feet. Your 1/66 scale to A reads + 50 and to C reads 10.
iii. You are standing at a horizontal distance of 100 feet. Your percentage scale reads 60 to A and -10 to C. iv. You are standing at a horizontal distance of 50 feet. Your percentage scale reads 40 to A and 10 to C. v. You are standing at a slope distance of 100 feet. Your percentage scale reads -20 to B, 95 to A, and -28 to C. C. Knowing your measurement rules [30 points] i. For each of these trees draw where on the stem of the tree you would measure DBH. [6 points] D. Knowing your Height Rules (10 points) 4.5 feet For each of these trees annotate the total height, crown base height, and estimate the live crown 4.5 feet ratio.
ii. For each of these trees mark with a line the total height (TH), crown base height (CBH), and estimate the live crown ratio (%) [30 points].
2. Land Survey and Mapping [120 points] Name: A. Define the following with words or a diagram [18 points]: i) Precision: ii) Accuracy: iii) Basal area: B. Why is there a difference between magnetic and true north and how do we account for those differences when using a compass? [10 points] C. Draw a diagram and describe how to determine the direction of flow of a river on a topo map. [10 points] D. Calculate the number of acres and hectares in the following land descriptions [24 points]: i) S6. ii) NW ¼ NW ¼ S. 12 iii) S ½ SW ¼ S. 4
E. Complete the following table [18 points]: Name: a b c A B C 30 55 70 A b C 20 10 10 40 60 75 c B a F. John uses a 36 dot per square inch dot grid to determine the area of a fire from a 1 : 62500 scale aerial photo and gets 66 in 2. How many acres and hectares burned [20 points]? G. Describe a method that would allow you to measure the area of all the lakes on a topographic map? [10 points] H. If you go 12 chains at 270⁰ turn and go 9 chains at 180⁰, what distance and direction do you need to travel to return to your starting location? [10 points]
3. Log Scaling [120 points] Name: A. Describe and define (with units) what each of the following measurements represent [20 points]: i. MBF ii. Cords iii. Mean Annual Increment iv. NPP v. NEP B. For each of the following logs calculate the Huber s AND Newton s Volume in cubic feet, state your assumptions. [40 points] Huber s Volume = B 1 / 2 *L Newton s Volume= (B+4B 1 / 2 +b)/6*l i. You have a 16 foot long log that is 6.2 inches at one end and 9.0 inches at the other end. ii. You have a 32 foot long log that is 24.0 inches at one end and 28.7 inches at the other end. iii. You have a 18 foot long log that is 32.0 inches at one end and 33.5 inches at the other end. iv. Calculate how many board feet are in each of the 3 logs listed above using the volume calculated from Huber s formula. Question Volume i ii iii
4. Growth and Yield [120 points] A. Site 1 Name: Site 1 Data: Tree Species DBH Height # code (in) (ft) 1 PIPO 20 112 2 PIPO 18 98 3 PIPO 22 108 4 PIPO 18 102 5 PIPO 13 67 i. Calculate the quadratic mean, mode, and range of the tree DBH [20 point] ii. If the trees in your stand all grew at a constant basal area increment of 0.0345 sq ft per year for the next 5 years, what would you expect the mean DBH to be in 5 years? [10 points] iii. If the data for Site 1 came from a 1/10 acre plot, calculate the trees per acre and basal area per acre [20 point] iv. Describe what Stand Density Index (SDI) is and tell how you would use the relative SDI. [10 points]
B. Expanded Site 1 Data Name: Site 1 Data: Tree Species DBH Height # code (in) (ft) 1 PIPO 20 112 2 PIPO 18 98 3 PIPO 22 108 4 PIPO 18 102 5 PIPO 13 67 6 PIPO 22 89 7 PIPO 13 65 8 PIPO 13 56 9 PIPO 19 102 10 PIPO 14 64 i. In this space draw a bar chart of the DBH and height distributions and state whether the distributions are normal or skewed. NOTE: you will have to select appropriate bin sizes. [10 points]: ii. Calculate the mean, mode, and range of the tree DBH [6 points]: iii. With the aid of a graph show how the DBH and height values are related and discuss under what circumstances it would be appropriate (and not appropriate) for this relationship to be used to predict DBH from a measure of the tree height across the range of tree ages [14 points]?
iv. Consider the following data collected for two plots in the same stand: Plot 1 Plot 2 Trees per acre 3500 70 Basal Area per Acre 400 80 Mean Basal Area 0.089 0.74 Quadratic Mean 4.63 14.67 Diameter Stand Density Index 992.29 224 i. By assuming that each plot just contained only Redwoods, Douglas Fir, or Longleaf Pine (consider each one separately) describe the level of stocking present at EACH of Plots 1 and 2 and describe what actions you may do if you were managing that stand for timber harvest. Redwoods [5 points]: Douglas Fir [5 points]: Longleaf Pine [5 points]: Use the following maximum SDI by Species in natural stands: Redwood = 1000 Douglas Fir = 595 Longleaf Pine = 400
Useful knowledge Sine Rule: (sin x)/x =( sin y)/y Cosine rule: Assume angle X is opposite side x. c^2 = a^2 + b^2 2*a*b*cos C 1 ha = 2.471 acres Area of circle = pi * (radius^2) QMD =