Appendix D. Individual MODIS-interval quality–quantity regression equations.
Table D1. Quality–quantity trade-off linear regression models
between herbaceous forage biomass (X1) and percentage digestibility
(Y), and the constant (
0), or average shrub percent digestibility
for leaves and twigs for each 16-d MODIS interval, and an overall
comparison between linear and exponential models for the herbaceous
quality–quantity trade-off over the entire growing season.
|
|
N |
F |
df |
P |
R2 |
Mean shrub% |
Mean shrub% |
|||||||||
| Modis interval linear model | |||||||||||||||||
8 May |
-0.45 (0.24) |
54.7 (14.4) |
13 |
3.5 |
7 |
0.1 |
0.25 |
70.8 |
68.6 |
66.8 |
64.0 |
||||||
24 May |
-0.12 (0.13) |
39.6 (8.9) |
11 |
0.5 |
9 |
0.5 |
0.05 |
70.5 |
69.8 |
65.8 |
65.6 |
||||||
9 Jun |
-0.09 (0.06) |
39.0 (5.5) |
27 |
2.3 |
25 |
0.12 |
0.09 |
71.1 |
70.7 |
66.3 |
66.9 |
||||||
25 Jun |
-0.10 (0.03) |
35.6 (3.4) |
28 |
11.9 |
26 |
0.02 |
0.17 |
72.2 |
70.5 |
66.5 |
66.9 |
||||||
11 Jul |
-0.13 (0.05) |
39.0 (4.3) |
41 |
7.6 |
25 |
0.01 |
0.25 |
71.8 |
69.7 |
66.9 |
65.4 |
||||||
27 Jul |
-0.10 (0.05) |
54.7 (4.7) |
26 |
3.6 |
13 |
0.07 |
0.11 |
69.5 |
70.6 |
64.7 |
66.0 |
||||||
12 Aug |
-0.10 (0.05) |
37.5 (3.3) |
42 |
3.9 |
28 |
0.05 |
0.15 |
68.6 |
69.0 |
63.6 |
63.6 |
||||||
28 Aug |
-0.18 (0.05) |
36.0 (3.8) |
26 |
14.1 |
19 |
0.001 |
0.39 |
67.2 |
67.0 |
63.0 |
62.9 |
||||||
13 Sep |
-0.33 (0.06) |
39.8 (2.5) |
9 |
37.0 |
7 |
0.005 |
0.7 |
67.1 |
66.7 |
63.1 |
63.8 |
||||||
29 Sep |
-- |
-- |
1 |
-- |
-- |
-- |
-- |
-- |
-- |
-- |
-- |
||||||
Annual herbaceous linear and exponential model |
|||||||||||||||||
Linear model |
-0.12 |
38.1 (2.6) |
224 |
15.7 |
33 |
0.001 |
0.18 |
69.9 |
69.2 |
65.2 |
65.0 |
||||||
Exponential
model |
|
|
|
N |
F |
df |
P |
R2 |
|||||||||
19.26 |
22.86 (4.564) |
0.96 (0.008) |
224 |
24.06 |
33 |
<0.001 |
0.22 |
||||||||||
Exponential
model |
Linear model |
||||||||||||||||
Notes: There was no significant linear or nonlinear relationship between shrub percentage DMD (dry-matter digestibility) either for leaf or twig and biomass, so the constant is reported. Note df is df2; df1 = 1 for all models. M = migrant elk, R = resident elk.
AICc = 0.00