Ecological Archives E096-114-A2
Adam F. A. Pellegrini, Lars O. Hedin, A. Carla Staver, and Navashni Govender. 2015. Fire alters ecosystem carbon and nutrients but not plant nutrient stoichiometry or composition in tropical savanna. Ecology 96:1275–1285. http://dx.doi.org/10.1890/14-1158.1
Appendix B. Tables illustrating statistical test results and descriptive statistics of tissue stoichiometry and community composition, and figures displaying tissue C:P ratios and community composition of trees.
Table B1. Statistical results from the linear mixed-effects model (all tests had 15 soil samples per plot nested within each experimental plot; denDF = 16 in all tests), with Tukey's HSD used to compare across treatments. Treatments are: 0 = unburned, 1 = 1yr FRT, and 3 = 3yr FRT.
Total soil pool |
||||
variable |
comparison |
p value |
||
Total C |
Treatment |
0.005 |
||
01 |
<0.001 |
|||
03 |
0.004 |
|||
31 |
0.580 |
|||
Total N |
Treatment |
<0.001 |
||
01 |
<0.001 |
|||
03 |
<0.001 |
|||
31 |
0.610 |
|||
Total P |
|
Treatment |
|
0.865 |
Table B2. Statistical results from ANOVAs of fire treatment effect on the size of tree biomass pools, with Tukey's HSD used to compare across treatments. Treatments are: 0 = unburned, 1 = 1yr FRT, and 3 = 3yr FRT.
Woody plant pool |
||||
variable |
comparison |
p value |
||
Total C |
Treatment |
0.007 |
||
01 |
<0.001 |
|||
03 |
<0.001 |
|||
31 |
0.02 |
|||
Total N |
Treatment |
0.007 |
||
01 |
<0.001 |
|||
03 |
0.002 |
|||
31 |
0.007 |
|||
Total P |
Treatment |
0.015 |
||
01 |
<0.001 |
|||
03 |
0.003 |
|||
|
|
31 |
|
0.09 |
Table B3. Statistical results from ANOVAs of fire treatment effect on the size of grass biomass pools, with Tukey's HSD used to compare across treatments. Treatments are: 0 = unburned, 1 = 1yr FRT, and 3 = 3yr FRT.
Grass pool |
||||
variable |
comp |
p value |
||
Total C |
Treatment |
0.16 |
||
01 |
0.11 |
|||
03 |
0.98 |
|||
31 |
0.08 |
|||
Total N |
Treatment |
0.26 |
||
Total P |
Treatment |
0.67 |
||
|
|
|
|
|
Table B4. Statistical results from ANOVA analyses of the effect of fire treatment on tissue stoichiometries across three different taxonomic selections: (1) All taxonomic groups; (2) Woody plants only; and (3) Grasses only. *Omocarpum outlier excluded (when included p < 0.069); §Flueggia virosa excluded (when included p < 0.026 for foliage and p < 0.08 for roots).
1) ALL TAXONOMIC GROUPS IN ANALYSIS:
Variable | Foliage |
Roots |
C:N |
N.S. |
N.S. |
C:P |
N.S. |
N.S. |
N:P |
N.S. |
N.S.* |
2) WOODY PLANTS ONLY:
Variable |
Foliage |
Roots |
C:N |
N.S. |
N.S. |
C:P |
N.S. |
N.S. |
N:P |
N.S.§ |
N.S.§ |
3) GRASSES ONLY:
Variable | Foliage | Roots |
C:N |
N.S. |
N.S. |
C:P |
N.S. |
p < 0.049 |
N:P |
N.S. |
p < 0.076 |
Table B5. Mean (µ) and standard deviation (σ) of tissue stoichiometric ratios across plant species in both foliar (Fol) and root (Root) tissues (n = 3 experimental plots; in each experimental plot leaves were collected and averaged from 6 individuals and roots from 3 individuals). All samples are from the 1yr FRT plots. Species definitions: A. nig = Acacia nigrescens, D. cin = Dichrostachys cinerea, C. sch = Commiphora schimperii., F. vir = Flueggea virosa, C. imb = Combretum imberbe, O. tri = Ormocarpum trichocarpum, and S. bir = Sclerocarya birrea.
|
|
|
C:N |
|
C:P |
|
N:P |
||||
µ |
σ |
µ |
σ |
µ |
σ |
||||||
A. nig |
Fol |
14 |
1 |
229 |
40 |
16.2 |
2.1 |
||||
Root |
51 |
2 |
966 |
132 |
19.0 |
3.2 |
|||||
D. cin |
Fol |
23 |
1 |
310 |
7 |
13.5 |
0.4 |
||||
Root |
57 |
1 |
551 |
45 |
9.7 |
1.0 |
|||||
E. rig |
Fol |
19 |
1 |
214 |
23 |
11.2 |
1.3 |
||||
Root |
92 |
10 |
356 |
182 |
3.9 |
1.5 |
|||||
C. imb |
Fol |
16 |
3 |
288 |
39 |
18.2 |
0.7 |
||||
Root |
35 |
2 |
561 |
7 |
16.0 |
0.1 |
|||||
O. tri |
Fol |
19 |
2 |
281 |
50 |
14.8 |
4.4 |
||||
Root |
33 |
9 |
316 |
193 |
9.5 |
2.8 |
|||||
C. sch |
Fol |
14 |
1 |
224 |
25 |
15.5 |
2.6 |
||||
Root |
39 |
10 |
314 |
83 |
8.1 |
1.7 |
|||||
S. bir |
Fol |
14 |
2 |
272 |
86 |
18.8 |
3.2 |
||||
Root |
28 |
11 |
718 |
221 |
25.3 |
14.9 |
|||||
F. vir |
Fol |
26 |
5 |
295 |
27 |
11.5 |
0.4 |
||||
Root |
57 |
19 |
423 |
83 |
7.4 |
1.7 |
|||||
Grass |
Fol |
45 |
13 |
114 |
28 |
2.5 |
1.2 |
||||
Root |
|
55 |
6 |
|
254 |
81 |
|
4.6 |
1.8 |
Table B6. Mean (µ) and standard deviation (σ) of tissue stoichiometric ratios across plant species in both foliar (Fol) and root (Root) tissues (n = 3 experimental plots; in each experimental plot leaves were collected and averaged from 6 individuals and roots from 3 individuals). All samples are from the unburned plots. Species definitions: A. nig = Acacia nigrescens, D. cin = Dichrostachys cinerea, C. sch = Commiphora schimperii., F. vir = Flueggea virosa, C. imb = Combretum imberbe,O. tri = Ormocarpum trichocarpum, and S. bir = Sclerocarya birrea.
|
|
|
C:N |
|
C:P |
|
N:P |
|||
µ |
σ |
µ |
σ |
µ |
σ |
|||||
A. nig |
Fol |
16 |
1 |
272 |
44 |
16.7 |
2.3 |
|||
Root |
43 |
12 |
476 |
184 |
11.1 |
9.2 |
||||
D. cin |
Fol |
23 |
3 |
295 |
78 |
12.8 |
1.3 |
|||
Root |
71 |
14 |
414 |
40 |
5.9 |
4.8 |
||||
E. rig |
Fol |
19 |
2 |
135 |
89 |
7.1 |
4.1 |
|||
Root |
45 |
15 |
249 |
228 |
5.5 |
3.1 |
||||
C. imb |
Fol |
17 |
2 |
304 |
37 |
17.6 |
1.3 |
|||
Root |
34 |
14 |
546 |
41 |
16.2 |
4.8 |
||||
O. tri |
Fol |
21 |
1 |
212 |
45 |
10.1 |
1.7 |
|||
Root |
50 |
16 |
369 |
136 |
7.4 |
3.2 |
||||
C. sch |
Fol |
16 |
2 |
135 |
40 |
8.7 |
2.8 |
|||
Root |
56 |
11 |
249 |
76 |
4.4 |
1.5 |
||||
S. bir |
Fol |
15 |
0 |
296 |
32 |
19.4 |
2.1 |
|||
Root |
37 |
6 |
481 |
130 |
12.9 |
4.7 |
||||
F. vir |
Fol |
23 |
5 |
223 |
49 |
9.7 |
1.9 |
|||
Root |
72 |
22 |
395 |
298 |
5.5 |
5.5 |
||||
Grass |
Fol |
48 |
19 |
184 |
116 |
5.6 |
5.0 |
|||
Root |
|
63 |
15 |
|
488 |
110 |
|
7.8 |
0.4 |
Table B7. Statistical results from the community composition (species replicated within each of 3 functional types; see text) data across the four metrics: (1) changes in relative (fraction within each plot) biomass 19542012; (2) changes in relative abundance 19542012; (3) relative biomass in 2012; (4) relative abundance in 2012. The interaction term (A, fire by functional type) indicates whether functional types differed in their response (either abundance or biomass) to fire. The direct effect of fire on N2 fixers (column B) evaluates the hypothesis that fire promotes the relative abundance or biomass of N2-fixing plants.
|
A. Interactive effect of |
B. Direct effect of fire on N2 fixers: |
1) Δ% biomass |
F4,59 = 0.34, p = 0.82 |
F1,16 = 0.38, p = 0.55 |
2) Δ% abundance |
F4,59 = 0.68, p = 0.61 |
F1,16 = 0.52, p = 0.48 |
3) % biomass |
F4,59 = 0.52, p = 0.72 |
F1,16 = 0.1, p = 0.76 |
4) % abundance |
F4,59 = 0.61, p = 0.66 |
F1,16 = 0.46, p = 0.51 |
Table B8. Descriptive statistics of changes in the relative biomass and abundance (fraction within each plot) of the seven focal species (mean and standard error) in the unburned and 1yr FRT experimental plots. Species definitions: A. nig = Acacia nigrescens, D. cin = Dichrostachys cinerea, C. sch = Commiphora schimperii., F. vir = Flueggea virosa, C. imb = Combretum imberbe,O. tri = Ormocarpum trichocarpum, and S. bir = Sclerocarya birrea. All results are percentages.
Species |
|
Δ% biomass (20121956) |
SE |
Δ% abundance (20121956) |
SE |
Unburned |
|||||
A. nig |
27.8 |
13.3 |
-22.1 |
7.1 |
|
D. cin |
-6.6 |
3.8 |
6.3 |
3.1 |
|
O. tri |
3.8 |
1.6 |
-6.3 |
2.6 |
|
E. rig |
4.4 |
3.5 |
13.0 |
4.6 |
|
F. vir |
-27.7 |
1.4 |
8.3 |
13.4 |
|
C. sch |
-6.1 |
5.4 |
9.3 |
6.1 |
|
C. imb |
-1.9 |
4.7 |
0.9 |
4.8 |
|
S. bir |
0.1 |
0.2 |
1.6 |
0.4 |
|
1yr FRT |
|||||
A. nig |
22.2 |
8.8 |
-17.0 |
5.2 |
|
D. cin |
-1.5 |
4.2 |
7.4 |
11.8 |
|
O. tri |
3.8 |
2.4 |
-6.3 |
6.5 |
|
E. rig |
3.1 |
1.1 |
2.0 |
3.8 |
|
F. vir |
-15.1 |
7.7 |
4.6 |
7.6 |
|
C. sch |
-0.6 |
-0.7 |
1.9 |
||
C. imb |
2.7 |
1.7 |
-1.1 |
0.8 |
|
S. bir |
|
0.1 |
1.9 |
2.9 |
0.7 |
Fig. B1. Tissue C:P ratios of vegetation foliar (F) and root (R) tissue (mean +/- standard deviation) in the unburned (blue) and 1yr FRT (red) fire treatments across 4 functional taxonomic groups. Species definitions: A. nig = Acacia nigrescens, D. cin = Dichrostachys cinerea, C. sch = Commiphora schimperii., F. vir = Flueggea virosa, C. imb = Combretum imberbe,O. tri = Ormocarpum trichocarpum, and S. bir = Sclerocarya birrea.
Fig. B2. Community composition of trees and shrubs across the unburned (blue) and 1yr FRT (red) fire treatments. (A) Relative biomass of each plant species in proportion to the entire plot-level biomass (mean +/- standard deviation). (B) Relative abundance of each plant species expressed as a fraction of the total number of plants in a plot (mean +/- standard deviation). Species definitions: A. nig = Acacia nigrescens, D. cin = Dichrostachys cinerea, C. sch = Commiphora schimperii., F. vir = Flueggea virosa, C. imb = Combretum imberbe,O. tri = Ormocarpum trichocarpum, and S. bir = Sclerocarya birrea.