ENVIRONMENTAL CONSEQUENCES in rocky mountain coniferous ...

As has already been stated, the forest land manager must be able to predict the
outcomes of those alternative harvest treatments he wishes to consider. This means
that he needs to know what the status of particular environmental characteristics
will be over time after treatment. Figure 5 might represent such a characteristic
vs. time relationship.
TREATMENT TIME
Figure 5. -- ~ nvirmenta2 characteristic versus time.
It would be ideal if we could factorially apply a broad array of treatments to
a variety of forest types and habitats and monitor forest development through rotation
to obtain a direct measure of vegetative response, This obviously is impossible.
Therefore, it seems necessary that we monitor more fundamental environmental charac-
teristics over short time periods and attempt to correlate these characteristics
with vegetative change to obtain a basis for prediction. The major problem we see
for researchers and staff specialists doing this concerns integrating primary environ-
mental characteristics into a holistic model to predict not only vegetative succes-
sion, but also other environmental consequences following treatment.
Most readers are fami 1 iar with model s for predicting vegetative succession and
stand development. Modelling efforts have been ongoing for several years now, and
have resulted in such products as Stage's (1 973) Stand Development Prognosis Model
and the Grassland Simulation Model (Innis 1978). One purpose of such models is to
meet the objectives we are concerned with here--that is, prediction of the state of
the environment (or at least of certain parts of the environment) at various points
in time. We will not attempt to make an exhaustive review or criticism of such
models here. Instead, we wish to discuss the general issue of environmental response
prediction, and the integration and extrapolation of basic environmental interactions
toward that end.
We are not prepared to suggest how the many environmental characteristics can
be combined in a deterministic model to predict their status over time on a specific
site, nor are we convinced this is even practicable. Nevertheless, we can suggest
some ways for coping with environmental interactions and estimating relatively
short-term changes.