SM {StreamMetabolism}

Calculate Ecosystem Production with the Single Station Method

Description

Calculate ER, NEP, and GPP from diurnal oxygen curves.

Usage

SM(depth, min_interval, DO, temp,
K, day, sr="00:00:00", ss="23:45:00",
start="00:00:00", end="23:45:00")

Arguments

depth

depth m K

min_interval

time resolution (e.g., 15 min)

temp

Zoo time Series temperature in degrees Celcius (see details)

DO

Zoo time Series Dissolved Oxygen in mg/L (see details)

day

date of the day of interest must be in quotes

start

time of the start of the "day" usually 00:00:00 must be in quotes

end

time of the end of the "day" usually 23:45:00 must be in quotes

sr

time of sunrise in the form 04:22:00 must be in quotes

ss

time of sunset in the form 19:23:00 must be in quotes

K

K at 20 deg. C (1/dt; e.g., 1/15min)

Details

The input data has to be a zoo time series constructed with a chron date time object of month/day/year hr:min:sec (i.e., 08/18/70 23:15:00)

sr and ss should be after and before the start and end of the time series, respectively.

ER is calculated as sum Et (i.e, mean nighttime NEP corrected for the difference in daytime temp and average nighttime temp)

GPP is calculated by summing NEP-ERt from sunrise to sunset

NEP=ER+GPP

Tested Against Rivermet spreadsheet (Izagirre 2007). The data from station 1 (7/10 - 7/15/2003) were used with K=0.07 from "Introduced K". ER, NEP, and GPP are in mg/L*d. The results were not identical. When Estimation from rivermet was regressed on estimation from this software, GPP, ER, and NEP intercepts did not differ significantly from 0 and slopes were nearly 1: 0.94, 0.91, and 0.95, respectively. Further testing is greatly appreciated.

Value

ER

Ecosystem Respiration

NEP

Net Ecosystem Production

GPP

Gross Primary Productivity

Author(s)

Stephen A Sefick Jr.

References

Odum, H. T. (1956). "Primary production in flowing waters." Limnology and Oceanography, 1: 102-117.

Thyssen, N., Erlandsen, M., Jeppesen, E., Holm T. F.,1983. Modelling the reaeration capacity of low-land streams

M.R. Grace and S.J. Imberger. 2006. "Stream Metabolism: Performing & Interpreting Measurements". Water Studies Centre Monash University, Murray Darling Basin Commission and New South Wales Department of Environment and Climate Change. 204 pp. Accessed at http://www.sci.monash.edu.au/wsc/docs/tech-manual-v3.pdf

Izagirre, O., M. Bermejo, J. Pozo, and A. Elosegi. 2007. RIVERMET: An Excel-based tool to calculate river metabolism from diel oxygen concentration curves. Environmental Modelling and Software, 22: 24-32.

Examples

#zoo real data
#velocity 0.6
#depth 0.4572
#sunrise 6:00AM
#sunset 8:15PM
#K/96 to get K per dt (i.e., 96 15 min interval in 1 day)
data(DOTemp)

K <- ODobbins(0.6, 0.4572)
prod <- SM(min_interval=15, K=K/96,
depth=0.4572, temp=DOTemp[,1], DO=DOTemp[,2],
day="8/18/70", start="00:00:00",
end="23:45:00", sr="06:00:00", ss="20:15:00")
prod