The equilibrium of the system is determined by the solution of eq. (14).
For
we have
where . It is obvious that
.
Since N>0 then
i.e. only within the interval
, where
.
It is interesting that the interval is reduced to a point, i.e. ,
if
, where
is defined as
It is obvious that, if ,
does
not exist, and there are the solutions
and
alone. In Fig. 8
the different N(T), corresponding to different values of A, are shown.
The maximum of N in respect to T is
. It
is obvious that
and it reaches that point at
.
Figure 8: The carbon mass in vegetation in equilibrium N as a function
of the equilibrium temperature T and the total amount of carbon A in the
system. For equilibrium with N=0 exist alone.
Let us remember the stability condition for the equilibrium
(see formulas (19)-(20)).
Since
,
then from (19) it follows:
i.e. this equilibrium is stable, and if
it is unstable.
Let us compare these expressions to (36). Hence, this equilibrium
is always unstable, if , and it is stable if
. It is obvious that for
the unique
equilibrium
exists and is stable.