Testing allometric scaling relationships in plant roots

Forest Ecosystems

Table 2 Summary of model II (reduced major axis) regressions of log₁₀- fine-root productivity (y) and -biomass (x) by ecosystem types, life forms, leaf phenology, and phylogeny. n is the number of samplings

Biome	Intercept	95% CI intercept	Slope	95% CI slope	r²	n
Ecosystem types
Boreal forests	0.082	0.108 ~ 0.053	1.003	0.833 ~ 1.139	0.238	184
Temperate forests	−0.036	−0.057 ~ –0.015	0.930	0.853 ~ 1.015	0.511	254
Subtropical forests	−0.125	−0.177 ~ –0.080	1.112	0.958 ~ 1.292	0.433	101
Tropical forests	−0.131	−0.203 ~ – 0.068	1.078	0.923 ~ 1.258	0.286	118
Temperate grasslands	−0.279	−0.417 ~ –0.166	0.938	0.780 ~ 1.128	0.594	50
Tropical grasslands	0.166	−0.287 ~ 0.423	0.731	0.415 ~ 1.284	0.287	12
Tundra	−0.085	−0.212 ~ 0.020	0.944	0.774 ~ 1.151	0.878	16
Wetlands	−0.149	−0.197 ~ –0.105	1.026	0.944 ~ 1.115	0.843	91
Life forms
Forbs	0.238	−0.350 ~ 0.496	0.738	0.323 ~ 1.685	0.747	5
Graminoids	−0.036	−0.140 ~ 0.082	0.928	0.814 ~ 1.057	0.850	38
Shrubs	0.043	−0.125 ~ 0.176	0.828	0.655 ~ 1.047	0.829	16
Trees	−0.050	−0.068 ~ –0.035	1.026	0.969 ~ 1.087	0.400	702
Leaf phenology
Deciduous	−0.135	−0.165 ~ – 0.105	0.983	0.920 ~ 1.050	0.626	333
Evergreen	−0.011	−0.031 ~ 0.008	1.010	0.942 ~ 1.082	0.387	493
Phylogeny
Angiosperm	−0.136	−0.162 ~ –0.111	1.016	0.959 ~ 1.077	0.564	497
Gymnosperm	0.046	0.028 ~ 0.063	0.967	0.890 ~ 1.050	0.418	329
All	−0.080	−0.121 ~ –0.039	0.980	0.934 ~ 1.029	0.508	826