Name: Section:

part 1: Form Identification

The first aerial photograph (Figure 15.7) shows some central Wisconsin forest in late spring 1975.

1. a. On the 1975 Photo (Figure 15.7), what tree form (needleleaf or broadleaf) appears in Quadrat A along the street? Broadleaf deciduous (probably birch and aspen)

b. What three interpretation qualities that are present or absent provided the best distinction of tree forms? Tone (no green foliage), shadow (basal bifurcations), texture (“twiggy” crowns)

2. a. On the 1975 photo (Figure 15.7), what tree form appears in Quadrat B?

Needleleaf evergreen (probably white pine)

b. What three interpretation qualities that are present or absent distinguish the tree(s) in B from tree(s) in A? Tone (solid lighter green), shape (conifer “star” branching), shadow (solid, with peaks)

3. a. On the 1975 photo (Figure 15.7), what plant community (needleleaf forest, broadleaf forest, grassland, or wetland) occurs at Quadrat C? Grassland

b. What three interpretation criteria that are present or absent distinguish this community from forest? Tone (pale green), texture (smooth and uniform), shadow (none evident)

4. a. On the 1975 photo (Figure 15.7), what plant community (needleleaf forest, broadleaf forest, grassland, or wetland) occurs at Quadrat D? Wetland (probably willow thickets)

b. What three interpretation criteria that are present or absent distinguish the Figure 15.7 Quadrat C community from the Quadrat D community? Tone (tan and brown), texture (mottled), shadow (small, but likely a cause for mottling)

Name: Section:

part 2: Changes in Habitat Areas

The large rectangular quadrat marked on the overlays for the 1975 (Figure 15.7) and 1981 (Figure 15.8) photos enclose the same tract. Comparing the two photos, quite a bit of change occurred over that six-year period. Not only had various human-made features (roads, buildings, etc.) moved or appeared, but much change also occurred to the forests and wetlands. The basic questions are thus, "How much change, and of what?"

The earlier photograph (Figure 15.7) was taken at 9:20am on 12 May, 1975; its image scale is 1:6,000 and the sun angle was 26.5° (tan 26.5=0.49858). Aircrews obtained the later photograph (Figure 15.8) at 11:40am on 23 March1981; its image scale is 1:6,429 and the sun angle was 46.2° (tan 46.2=1.04279). Because photocopiers may reduce or enlarge from the originals, we provide the measurements of image shadow lengths (in millimeters) below for making your height calculations. The tree in the small Quadrat E is a jack pine (Pinus banksiana), which is a light-loving, fast-growing (0.4 m/yr), and short-lived pioneer species typical of secondary succession.

1. What was the height in meters of the tree at Quadrat E in 1975? (Image shadow = 1.75 mm) (((1.75/1000).49858)6000)=5.23 meters

2. What was the height in meters of this tree in 1981 Photo? (Image shadow = 1.00 mm)

(((1.00/1000)1.04279)6429)=6.79 meters

3. Does the amount of growth for the Quadrat E tree seem reasonable, given the amount of time that elapsed between photographs?

Growth of ~0.25 m/yr (~.8 ft) is reasonable for jack pine

Consider only the areas within the large quadrat for Questions 4 through 8. The scale of the 1975 photo is 1:6,000 and for the 1981 photo is 1:6,429. As an example, the 1975 calculations are:

The total image area dot count in the 1975 quadrat was 8,350:

X km² = 83.5 cm²_image X 36,000,000 cm² X 1 m² X 1 km² = 0.3006 km²

1 1 cm² _image 100² cm² 1000² m²

The 1975 dot count for the non-needleleaf plant area (Figure 15.9) was 6578:

X km² = 65.78 cm²_image X 36,000,000 cm² X 1 m² X 1 km² = 0.2368 km²

1 1 cm² _image 100² cm² 1000² m²

The 1975 dot count for the needleleaf area (Figure 15.9) was 1772:

X km² = 17.72 cm²_image X 36,000,000 cm² X 1 m² X 1 km² = 0.0638 km²

1 1 cm² _image 100² cm² 1000² m²

Repeat the same computation procedures for 1981 to show how much change occurred in forest cover. Scale is 1:6,429.

4. Total ground area in the 1981 quadrat is:

7273 dots = 72.73 cm² ((7273^1/2) 0.006429)² = .3006 km²

5. Non-needleleaf ground area in 1981 (Figure 15.10) is:

6411 dots = 64.11 cm² ((6411^1/2) 0.006429)² = .2650 km²

6. Needleleaf ground area in 1981 (Figure 15.10) is:

862 dots = 8.62 cm² ((862^1/2) 0.006429)² = .0356 km²

7. Absolute change of needleleaf area from 1975 to 1981 was:

(1981 area 0.0356 km²)

- (1975 area 0.0638 km²)

(include sign) = Change -0.0282 km²

8. One km² = 100 hectares. Suppose that a single barn owl requires either 0.5 hectares of needleleaf forest or 0.3 hectares of non-needleleaf vegetation to survive. How many total barn owls could our quadrat support in 1975, and then in 1981?

1975 1981

a. How many hectares are of non-needleleaf vegetation? 23.68 26.50

b. How many hectares are of needleleaf forest? 6.38 3.56

c. How many barn owls could this quadrat support:

in the non-needleleaf area? 78.93 88.33

in the needleleaf area? 12.76 7.12

Total owls: 91.69 95.45