Ecological Archives E096-115-A3
Steve J. Kroiss and Janneke HilleRisLambers. 2015. Recruitment limitation of long-lived conifers: implications for climate change responses. Ecology 96:1286–1297. http://dx.doi.org/10.1890/14-0595.1
Appendix C. Model selection for seed and microsite limitation models.
Table C1. Factors influencing seed limitation for focal species, as determined by AIC model selection of explanatory variables explaining seed availability. We asked how basal area (parent abundance), year and their interaction influenced seed availability. Most parsimonious models are bolded, with those less than two AIC units considered equally parsimonious. Δi (AIC) = AICi – min(AIC); wi (AIC) = the rounded Akaike weights. Asterisks indicate significance levels (* = P < 0.05; ** = P < 0.01; *** = P < 0.001).
Species |
Model |
AICi |
Δi (AIC) |
wi (AIC) |
Thuja plicata |
Null (random effects only) |
2089.9 |
238.4 |
<0.001 |
Basal area |
2085.6 |
234.1 |
<0.001 |
|
Year |
1875.9 |
24.4 |
<0.001 |
|
Basal area (***) × Year (***) |
1851.5 |
0 |
1 |
|
Pseudotsuga menziesii |
Null (random effects only) |
1169.5 |
43.0 |
<0.001 |
Basal area |
1165.3 |
38.7 |
<0.001 |
|
Year |
1127.9 |
1.4 |
0.334 |
|
Basal area (**) × Year (*) |
1126.6 |
0 |
0.666 |
|
Tsuga heterophylla |
Null (random effects only) |
3794.5 |
494.9 |
<0.001 |
Basal area |
3778.8 |
479.2 |
<0.001 |
|
Year |
3308.2 |
8.6 |
0.013 |
|
Basal area (***) × Year (***) |
3299.6 |
0 |
0.987 |
|
Abies amabilis |
Null (random effects only) |
1617.4 |
261.6 |
<0.001 |
Basal area |
1597.8 |
242.0 |
<0.001 |
|
Year |
1374.9 |
19.1 |
<0.001 |
|
Basal area (***) × Year (**) |
1355.7 |
0 |
1 |
|
Callitropsis nootkatensis |
Null (random effects only) |
768.9 |
41.7 |
<0.001 |
Basal area |
760.1 |
32.9 |
<0.001 |
|
Year |
733.3 |
6.2 |
0.043 |
|
Basal area (***) × Year (*) |
727.1 |
0 |
0.957 |
|
Tsuga mertensiana |
Null (random effects only) |
1274.3 |
123.8 |
<0.001 |
Basal area |
1263.2 |
112.7 |
<0.001 |
|
Year |
1194.3 |
43.9 |
<0.001 |
|
Basal area (***) × Year (**) |
1150.5 |
0 |
1 |
Table C2. Factors influencing microsite limitation for focal species, as determined by AIC model selection of explanatory variables explaining germination. We asked how well snowpack duration, soil moisture, canopy density and understory competitive cover influenced germination. Most parsimonious models are bolded, with those less than two AIC units considered equally parsimonious. Δi (AIC) = AICi – min(AIC); wi (AIC) = the rounded Akaike weights.
Species |
Model |
AICi |
Δi (AIC) |
wi (AIC) |
Thuja plicata |
Null (random effects only) |
1409.9 |
278.9 |
<0.001 |
Snowpack duration |
1381.4 |
250.4 |
<0.001 |
|
Soil moisture |
1411.6 |
280.6 |
<0.001 |
|
Canopy density |
1148.8 |
17.8 |
<0.001 |
|
Understory competitive cover |
1406.9 |
275.9 |
<0.001 |
|
Full (all variables) |
1131 |
0 |
1 |
|
Pseudotsuga menziesii |
Null (random effects only) |
284.4 |
26 |
<0.001 |
Snowpack duration |
276.9 |
18.5 |
<0.001 |
|
Soil moisture |
284.3 |
25.9 |
<0.001 |
|
Canopy density |
262 |
3.6 |
0.147 |
|
Understory competitive cover |
286.5 |
28.1 |
<0.001 |
|
Full (all variables) |
258.4 |
0 |
0.853 |
|
Tsuga heterophylla |
Null (random effects only) |
4685.1 |
645.8 |
<0.001 |
Snowpack duration |
4592.8 |
553.5 |
<0.001 |
|
Soil moisture |
4679.3 |
640 |
<0.001 |
|
Canopy density |
4191.9 |
152.6 |
<0.001 |
|
Understory competitive cover |
4591.7 |
552.4 |
<0.001 |
|
Full (all variables) |
4039.3 |
0 |
1 |
|
Abies amabilis |
Null (random effects only) |
618.5 |
20.6 |
<0.001 |
Snowpack duration |
609.5 |
11.6 |
0.003 |
|
Soil moisture |
620.6 |
22.7 |
<0.001 |
|
Canopy density |
612.6 |
14.7 |
0.001 |
|
Understory competitive cover |
606.8 |
8.9 |
0.011 |
|
Full (all variables) |
597.9 |
0 |
0.985 |
|
Callitropsis nootkatensis |
Null (random effects only) |
288 |
9.9 |
0.006 |
Snowpack duration |
288.7 |
10.6 |
0.005 |
|
Soil moisture |
286.9 |
8.8 |
0.011 |
|
Canopy density |
287.3 |
9.2 |
0.009 |
|
Understory competitive cover |
284.6 |
6.5 |
0.035 |
|
Full (all variables) |
278.1 |
0 |
0.934 |
|
Tsuga mertensiana |
Null (random effects only) |
915.3 |
221.1 |
<0.001 |
Snowpack duration |
777.4 |
83.2 |
<0.001 |
|
Soil moisture |
831.9 |
137.7 |
<0.001 |
|
Canopy density |
884.7 |
190.5 |
<0.001 |
|
Understory competitive cover |
869.3 |
175.1 |
<0.001 |
|
Full (all variables) |
694.2 |
0 |
1 |