symbols for this diagram were adapted from Odum (1994) (Appendix 6.B). Table 6.2
 provides the equations for each flow shown in Figure 6.5.

 The model uses a reclaimed forested wetland as the system boundary. The main
 components in this model included storage, producers, and outside sources (forcing
 functions). Within the system, there are three producers, herbaceous vines, woody vines,
 and trees. The herbaceous and woody vines each have one storage of living vine
 biomass; the trees have two storage, living tree biomass and tree nutrients. This
 difference is used to show the more rapid turnover time (and faster organic matter
 production) attributed to vines versus the longer turnover time of trees (and slower
 organic matter production). In systems ecology language, turnover time refers to the
 steady state value of the storage divided by the outflows. It represents the life span of the
 storage.

 Nutrients are shown as a flow through the system as opposed to a storage within
 the system because nutrients have a much faster turnover time than plant biomass
 (Jackson 1999). This flowing pathway of nutrients feeds the production of living
 biomass for vines and trees and drives the accumulation of tree nutrients. When biomass
 dies and is no longer part of the producers, most decays and is incorporated as soil
 organic matter. This organic matter is then recycled by decomposing soil
 microorganisms and contributes to the flow through of nutrients.


 Model Calibration

 Mathematical equations for this model were written according to Odum (1994)
 and calculated for "steady state." "Steady state" is described when a system has equal
 inflows and outflows and when storage are constant (Odum 1994). "Steady state"
 values are useful when calculating unknown pathways and calibrating coefficients. The
 initial "steady state" coefficients in this model were calibrated based on previous field
 studies, publications, and turnover times (Jackson 1999; Odum and Odum 1996; Odum
 1994; Mitsch and Gosselink 1993; Myers and Ewel 1990).

 Figure 6.6 shows the systems diagram with the coefficients labeled. Table 6.3
provides the values used for each coefficient, calibrated for steady state. This model
simulated 200 years of development of reclaimed forested wetlands beginning at the time
of wetland establishment. Some assumptions are involved, including finding acceptable
average turnover times for herbaceous vines, woody vines, and trees. Additionally,
during the initial stages of wetland forest development when reclaimed wetlands are
initially planted, there was an assumption that some vine biomass existed on-site. This
vine biomass may have entered through seeds in the mulched soil layer, through tree
nursery stock, or as volunteers from nearby seed sources. Four separate simulations were
run representing forested wetland succession following site establishment, forested
wetland succession in the absence of vines, forested wetland succession when vine
management occurs in year 7, and forested wetland succession when vine biomass is
controlled when the storage of herbaceous vine biomass equals 20%.


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