Soil Water Budgets

Name:_______________________________________________________ Section:

part 1: data compilation

1. Calculate Im to the nearest whole number for the last ten stations in Table 14.2 using equation 1.

2. Locate these same ten stations at “x”s on the maps of ecoregions (Figure 14.2) and soil orders (Figure 14.3). Record the letter codes representing the vegetation and soil at each station (Table 14.1) to complete Table 14.2. For mixed vegetation, use the first type listed in the ecoregions map (Figure 14.2) key.

TABLE 14.1 Vegetation and Soil Codes

Use:	For:	Use:	For:
R	Tropical Rainforest	s	Spodosols ("ash-colored")
B	Broadleaf temperate forest	a	Alfisols ("aluminum & iron stains")
N	Needleleaf forest	m	Mollisols ("soft & friable")
S	Savanna	u	Ultisols ("old")
G	Grassland	o	Oxisols ("oxidized")
D	Desert	v	Vertisols ("turning over")
T	Tundra	h	Histosols ("tissue-like")
		d	Aridisols ("dry")
		e	Entisols ("recent")
		i	Inceptisols ("beginning")
		v	Andisols (“volcanic andesite”)
		g	Gelisols (“gelifluction & frost heaving”)

TABLE 14.2 Station Data

#	Station	Location	P	PE[NcH1]	Im	Vegetation	Soil
1	Buenos Aires, Argentina	35S/059W	1005	759	+32	G	m
2	Belem, Brazil	02N/049W	2833	1537	+84	R	i
3	Monterrey, Nuevo Leon	26N/100W	606	1100	-45	D	d
4	Oklahoma City, Oklahoma	36N/098W	818	776	+5	G	m
5	Tucson, Arizona	32N/111W	295	1024	-71	D	d
6	El Oregano, Sonora	29N/111W	363	1731	-79	D	d
7	Tonopah, Nevada	40N/116W	134	576	-77	D	d
8	Berthoud Pass, Colorado	40N/106W	958	285	+236	T	i
9	Williston, North Dakota	48N/104W	352	487	-28	G	m
10	Minneapolis, Minnesota	44N/093W	701	532	+32	B	a
11	Fairbanks, Alaska	65N/148W	268	357	-25	N	g
12	Barrow, Alaska	71N/157W	112	222	-49	T	g
13	Hay River, Northwest Territories	61N/116W	326	336	-3	N	s
14	Cartwright, Newfoundland	54N/057W	966	336	+187	T	e
15	Dryden, Ontario	50N/093W	671	424	+58	B	s
16	Moose Jaw, Saskatchewan	51N/106W	368	453	-19	G	m
17	Edmonton, Alberta	54N/114W	454	426	+7	N	a
18	Windsor, Ontario	42N/083W	831	549	+51	B	a
19	Churchill, Manitoba	59N/094W	402	268	+50	T	h
20	Reykjavik, Iceland	64N/016W	818	410	+100	T	g
21	Cork, Ireland	52N/009W	1081	563	+92	B	a
22	Turku, Finland	61N/022E	632	419	+51	B	s
23	Murmansk, Russia	69N/033E	412	321	+28	N	s
24	Irkutsk, Russia	52N/105E	418	378	+11	N	i
25	Urumqi, China	44N/881E	254	558	-54	D	d
26	Ho Chi Minh City, Vietnam	11N/107E	1934	1712	+13	S	u
27	Kolkata, India	23N/089E	1633	1781	-8	S	u
28	Tehran, Iran	36N/052E	239	848	-72	D	d
29	Singapore, Singapore	01N/104E	2272	1687	+35	R	o
30	Cairo, Egypt	30N/031E	28	1035	-97	D	d
31	Douala, Camaroon	4N/010E	4000	1380	+165	R	o
32	Windhoek, Namibia	23S/017E	367	865	-58	D	d
33	Cape Town, South Africa	34S/019E	611	753	-19	S	a
34	Mombasa, Kenya	04S/040E	1144	1587	-28	S	a
35	Entebbe, Uganda	00S/033E	1535	971	+58	S	u
36	Banjarmasin, Indonesia	04N/115E	2553	1610	+59	R	o
37	Maputo, Mozambique	26S/033E	767	1078	-29	S	d
38	Kisangani, Congo	01N/025E	1858	1273	+46	R	o
39	Harare, Zimbabwe	18S/031E	827	813	+2	S	a
40	Luanda, Angola	09S/013E	369	1207	-69	S	d
41	Green Bay, Wisconsin	45N/090W	725	504	+44	B	a
42	Longmont, Colorado	40N/105W	327	544	-40	G	d
43	St. Louis, Missouri	39N/090W	939	698	35	G	a
44	Washington, DC	39N/077W	990	725	37	B	u
45	Atlanta, Georgia	34N/084W	1237	783	58	B	u
46	Manaus, Brazil	03S/060W	2081	1611	29	R	i
47	Iquitos, Peru	04S/073W	2878	1519	89	R	o
48	Leticia, Colombia	04S/071W	2811	884	218	R	o
49	Iquique, Chile	20S/070W	2	793	-100	D	d
50	Brasilia, Brazil	16S/048W	1555	920	-13	G	a

Name:________________________________________________ Section:________________

part 2: graph classifications

1. Figures 14.4 (vegetation graph) and 14.5 (soils graph) were created using the data in Table 14.2. Plot the last ten stations on each graph.

2. Encircle clusters of the same letters on Figures 14.4 (vegetation graph) and 14.5 (soils graph) (skip this for entisols and inceptisols), after the grassland and mollisol examples. The enclosure lines may overlap. Then shade the separate clusters in different colors. It would be a good idea to do this in pencil!

3. Compare Figures 14.4 (vegetation graph) and 14.5 (soils graph) with Figure 14.1. While you will have some difference in appearance, there should also be some degree of correspondence between your patterns and those of Figure 14.1.

a. Which of your vegetation and soils zones seem to fall most consistently into their correct places according to Figure 14.1? R, D, G for biomes; o, a, d, m, and s for soils

b. Which of your vegetation and soils zones seem to fall most inconsistently into their correct places according to Figure 14.1? B, N for vegetation; e, I, a for soils

4. List all vegetation and the soil orders on Figures 14.4 (vegetation graph) and 14.5 (soils graph) that correspond most closely with the following climates:

Climate	Vegetation Letter Code(s)	Soil Letter Code(s)
Tropical (Köppen A)	R, S	o, u
Subtropical (Köppen C)	S, B	a, u
Continental (Köppen D)	B, N	a, s
Frozen (Köppen E)	T, N	i, h, s
Arid (Köppen B)	D, G, S	a, d, m

Figure 14.4 Vegetation Graph

Figure 14.5 Soil Orders Graph

Name: Section:

Part 3: Interpretive Applications

Description

1. What soil(s) and climate(s) best correspond to each vegetation? Use Table 14.2, Figure 14.4 (vegetation graph), and Figure 14.5 (soils graph).

Vegetation	Soil Code	Climate
Tropical Rainforest (R)	o, u	A
Broadleaf Temperate Forest (B)	a, d	B, C, D
Needleleaf Forest (N)	s	D
Savanna (S)	a, d, u	A, B
Grassland (G)	d, m	B, C
Desert (D)	d	B
Tundra (T)	e, h, i	E

2. Draw a line that separates forest from non-forest vegetation on the vegetation graph (Figure 14.4). This line shows the environmental limits to forest vegetation, something we can actually see on the landscape – the treeline: a boundary beyond which trees do not grow.

3. a. What would be a good approximate cutoff Im value separating savanna from desert?

-50

b. What would be a good approximate cutoff PE value separating tundra from forest?

300 mm

c. Describe the temperature and moisture conditions necessary for forest to exist.

Almost any temperature (PE), but usually moist (Im>0) unless alternative sources of water are available (e.g., some climatic dry Broadleaf are riverbank forests)

Explanation

Some soil orders (e.g., mollisols) cluster pretty much into their own exclusive areas on Figure 14.5. Others (e.g., oxisols and ultisols) seem to share part of their graph zones. Some orders, inceptisols and entisols, do not seem to cluster very much at all, but appear almost randomly on the graph. Consider the meaning of the axis variables in Figures 14.4 and 14.5 as you try to explain soil occurrence tendencies below.

4. Name another soil order that clusters into its own graph zone. What vegetation (on Figure 14.4) does this soil consistently coincide with, and what climatic conditions evidently exist where this soil and vegetation develops?

Soil Vegetation Climate

D (cold, but humid enough for forest)

5. a. Name two soil orders that overlap, and thus share a graph zone. a & m, or o & u

b. What climatic conditions (hot/cold, wet, dry) does their overlap represent?

moderate heat and moisture, or variably humid but warm

c. What non-climatic factors might cause these two different soils to form under similar climatic conditions?

Soil/bedrock permeability, sea level changes, bedrock composition, etc.

6. What non-climatic situations could produce entisols and inceptisols across a variety of different climates, as these soil orders appear within Figure 14.5?

geologic disturbances (volcanoes, isostacy, etc.), hydrologic alteration

7. Some of the vegetation (Figure 14.4) may overlap or contain outlyers, implying that several types of vegetation coexist together. Give one possible explanation for joint (instead of exclusive) occupation of the same graph zone by unlike vegetation.

Competition, adaptation, importation, relictual distributions, human management

Prediction

8. Using your graphs and comparing the PE and Im values in Table 14.1, what vegetation and soil (use our letter codes) do you predict for the following hypothetical places? Then indicate locations where each of these ecosystems might typically occur.

PE	Im	Vegetation	Soil	Likely North America Location
375	-5	N	s	central Canada
610	-31	G	m, a, d	western Great Plains
733	+27	B, G, S	a, m, u	southern Great Plains (Texas)
1225	-95	B, D	d	New Mexico, Arizona, Sonora
1475	+105	R	o, u	Caribbean, Middle America