. 2017 May 16;7:1959. doi: 10.1038/s41598-017-02035-1

Table 8.

ANCOVAs of the effect of seed mass (covariate) and habitat (roadside vs forest) on the nitrogen (N), phosphorus (P) or potassium (K) content in seeds based on the data pooled across umbel orders.

Nutrient	Seed mass	Habitat	Habitat × seed mass	Roadside (mg seed⁻¹)	Forest (mg seed⁻¹)
Nitrogen	2789.28***	6.56*	7.01*	0.16 ± 0.004a	0.21 ± 0.008b
Phosphorus	1356.14***	5.44*	6.12*	0.03 ± 0.004a	0.04 ± 0.004b
Potassium	342.31***	6.34*	5.98*	0.07 ± 0.005a	0.12 ± 0.006b
N:P	45.32^ns	1.45^ns	3.32^ns	5.33 ± 0.24	5.25 ± 0.31

Total reserves of seeds (N, P or K mg seed⁻¹) were calculated from the mass (mg dry weight [dry wt]) of each seed multiplied by the relative N, P or K concentration (% dry wt). Individual seed mass was obtained by taking the mean mass of sample of 100 seeds (N = 10 samples).

F-values for seed mass, habitat, and habitat × seed mass are given. *p < 0.05, **p < 0.01, ***p < 0.05. The values for seed mass followed by different letter in the same row are significantly different at p < 0.05 according Student’s t-test procedure.