Preface
As science, ecology is often accused of being weak because of its basic lack of
predictive power (Peters 1991) and the many ecological concepts judged vague
or tautological (Shrader-Frechette and McCoy 1993). Also, important paradigms that dominated the ecological scene for years have been discarded in
favor of new concepts and theories that swamp the most recent ecological
literature (e.g., the abandoning of the island biogeography theory in favor of
the metapopulations theory; Hanski and Simberloff 1997). The apparent ease
with which such changes seem to be accepted could be taken as an intrinsic
weakness of ecological disciplines; in fact, many ecologists seem to have an inferiority complex with respect to sciences considered more rigorous, such
as physics or chemistry. Thus, when ecology has to provide the basis for environmental conservation and management, this presumed weakness is easily
instrumentalized by those opposing conservation. In the often sterile debates
that are heard, ecology loses credibility and is easily victimized by its detractors.
It is not surprising that many ecological theories and concepts have still not
been defined precisely, given the enormous complexity of ecological systems.
Yet ecology is rooted in the scientific method applied to the observation and
experimentation of natural facts. Rather than a discipline whose experimental
practice is informed by laws and invincible paradigms, ecology is a classically
bottom-up discipline in which the application of the scientific method to real
facts and processes gradually builds a body of knowledge that can give rise to
useful generalizations. But the complexity of ecological processes and their
variability is such that any generalization conflicts with the need to account for
all possible variations. It is in this light that the rigor of the results achieved in
the study of real cases takes on fundamental value. Without embracing such
As science, ecology is often accused of being weak because of its basic lack of
predictive power (Peters 1991) and the many ecological concepts judged vague
or tautological (Shrader-Frechette and McCoy 1993). Also, important paradigms that dominated the ecological scene for years have been discarded in
favor of new concepts and theories that swamp the most recent ecological
literature (e.g., the abandoning of the island biogeography theory in favor of
the metapopulations theory; Hanski and Simberloff 1997). The apparent ease
with which such changes seem to be accepted could be taken as an intrinsic
weakness of ecological disciplines; in fact, many ecologists seem to have an inferiority complex with respect to sciences considered more rigorous, such
as physics or chemistry. Thus, when ecology has to provide the basis for environmental conservation and management, this presumed weakness is easily
instrumentalized by those opposing conservation. In the often sterile debates
that are heard, ecology loses credibility and is easily victimized by its detractors.
It is not surprising that many ecological theories and concepts have still not
been defined precisely, given the enormous complexity of ecological systems.
Yet ecology is rooted in the scientific method applied to the observation and
experimentation of natural facts. Rather than a discipline whose experimental
practice is informed by laws and invincible paradigms, ecology is a classically
bottom-up discipline in which the application of the scientific method to real
facts and processes gradually builds a body of knowledge that can give rise to
useful generalizations. But the complexity of ecological processes and their
variability is such that any generalization conflicts with the need to account for
all possible variations. It is in this light that the rigor of the results achieved in
the study of real cases takes on fundamental value. Without embracing such