| EcoNetwrk is based on Netwrk 4.2 by Robert E. Ulanowicz (http://www.cbl.cees.edu/~ulan/ntwk/network.html). EcoNetwrk performs all of the analysis of Netwrk 4.2 but in a windows friendly environment. Netwrk 4.2 is copyrighted (1982, 1987, 1998, 1999) and was used with the author's permission and guidance.
What is Network Analysis?
Network analysis is a phenomenological approach that holistically quantifies the structure and function of food webs by evaluating biomasses and energy flows. The efficiency with which energy and material is transferred, assimilated, and dissipated conveys significant information about the structure and function of food webs (Ulanowicz 2004; Ulanowicz and Platt 1985; Baird and Ulanowicz 1989 and 1993; Baird et al. 1991; Ulanowicz and Wulff 1991). Network analysis has been used to compare ecosystems of different size, geographical location, hydrological characteristics, and trophic status (Baird et al. 1991; Ulanowicz and Wulff 1991; Baird and Ulanowicz 1993; Monaco and Ulanowicz 1997). Most recently, arguments have been advanced for the use of network analysis to quantify the health and integrity of ecosystems (Ulanowicz 2000) and to evaluate the magnitude of stress imposed on an ecosystem (Ulanowicz 1995; Mageau et al. 1998).
There are fundamentally four types of analyses in network analysis: (1) input/output analysis, (2) the determination of trophic status and the identification of an equivalent linear food chain, (3) elaboration and analysis of biogeochemical cycling and the supporting flows, and (4) calculation of ecosystem indices (or properties) derived from information theory that describe the state of the food web.
EcoNetwrk References EcoNetwrk Development Team
Team Leader: Doran M. Mason, Ph.D. (NOAA/GLERL)
Model Development: Robert E. Ulanowicz, Ph.D. (Chesapeake Biological Laboratory, University of Maryland)
Technical consultants: Ann Krause (GLFC, Michigan State University), Andrea Jaeger (Michigan State University)
Programmers: Tim Hunter, Anne Clites (NOAA/GLERL)
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Download the latest version of EcoNetwrk:
(For information on recent updates, see changes log.) Installation package (6.01 mb -- includes updated user's manual: February 2007)
Windows Application (EcoNetwrk.exe) (1.11 mb -- updated 7 February 2007)
EcoNetwrk.dll File (Required in same directory as EcoNetwrk.exe) (678 kb -- updated 10 December 2004) User's Manual (MS Word, 12 December 2006) Input: Standard SCOR-format file, comma-delimited csv file, EcoNetwrk file Output: The current version of EcoNetwrk produces output in the same format as NETWRK 4.2 User notes: EcoNetwrk is a tool designed to make it easier to use the Ulanowicz NETWRK model. It currently opens SCOR or CSV files, checks for a balanced network, balances the network using DATBAL, executes the analysis, and automatically saves the output as 'DEFAULT.OUT' in the folder where EcoNetwrk resides. Interactive data entry is also permitted. A number of options are available (intermediate steps) on the 'Calculate' menu. EcoNetwrk is compatible with Windows 95 and above. Graphical display of output is a desired later stage of this project. A brief User's manual is included with the installation package. Your comments will help us improve the documentation. Questions? EcoNetwrk@noaa.gov |
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