Ecological Archives E089-200-A10

H. M. Valett, S. A. Thomas, P. J. Mulholland, J. R. Webster, C. N. Dahm, C. S. Fellows, C. L. Crenshaw, and C. G. Peterson. 2008. Endogenous and exogenous control of ecosystem function: N cycling in headwater streams. Ecology 89:3515–3527.

Appendix J. Seasonal spiraling metrics for forested and open-canopied streams.

TABLE J1. Seasonal spiraling metrics for forested (n = 4) and open-canopied (n = 2) streams. Data are means* ± SE.

Seasons Summer Autumn Winter Spring
Forested        
Uptake length
(SW, m)
752 ± 675 16 ± 8 192 ± 96 513 ± 281
Uptake velocity
(vf, mm/s)
0.01 ± 0.01 0.09 ± 0.03 0.02 ± 0.01 0.01 ± 0.01
Uptake rate
(U, µg N·m-2·s-1)
0.13 ± 0.04 0.62 ± 0.22 0.08 ± 0.02 0.08 ± 0.02
         
Open        
Uptake length
(SW, m)
1349 ± 1326 87 ± 70 1430 ± 1118 not sampled
Uptake velocity
(vf, mm/s)
0.03 ± 0.03 0.03 ± 0.03 0.01 ± 0.01 not sampled
Uptake rate
(U, µg N·m-2·s-1)
0.32 ± 0.02 0.22 ± 0.02 0.06 ± 0.02 not sampled

* Mean values within a row were not significantly different (P < 0.005) as determined by Tukey’s Multiple Comparison Test following one-way ANOVA (season = main effect). Statistical results from NCNM are based on n = 2/season.


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