Most works dealing with ecological stability are
based on theoretical rather than experimental research.
Consequently, this theoretical knowledge has not been
applied in management for stability in an ecological
sense. The following discussion of possibilities through
silvicultural measures to ensure stability of managed
forests will primarily focus upon the stability of the tree
species compartment in terms of structural features
(genetic variation, species diversity, age and size, life
span) and functional parameters (long term productivity
including maintenance of biotic and abiotic
resources).
In natural ecosystems there seems to be an inverse
relationship between resistance and resilience. Hence
biotic factors which tend to increase resistance (diversity,
complexity, coadaptation) decrease resilience and
vice versa. This interrelation between resistance and
resilience seems to reflect the development of the ecosystem
as response to the types of perturbation commonly
encountered by the system and their distribution
in time and space (see also Section 2.1.) . However,
man may influence resistance and resilience independently,
since they are not obligatory functionally
linked. This emphasises the danger that management,
unaware of the basic principles of stability, might
reduce both resistance and resilience and thus decrease
stability. Numerous examples exist, including introduction
of unadapted species and provenances, reduction
of the genetic resource base through selection and
breeding, large scale conversion of natural mixed for