Next: Bibliography
Up: Implications of Island Biogeography
Previous: The SLOSS debate
Although in some ways the SLOSS debate may seem like a dead end,
there are several important points to remember:
- The suggestion that a single large reserve was preferable
emerged from a respectable, legitimate body of ecological
understanding. Just as ecologists and evolutionists have often
followed blind alleys, conservationists can be expected to. In
fact, you could argue that if we don't occasionally make mistakes we
are avoiding difficult problems.
- Reserve designs must serve a purpose. Reserves designed to
protect plant diversity may be entirely different in character from
those designed to protect vertebrate diversity. Reserves designed
to protect exemplary natural communities will have a focus different
from those designed to protect an endangered species.
- Reserve designs are more frequently guided by where
elements of concern occur than by a priori theories about
the best configuration of preserves. A little common sense, some
basic biological and ecological awareness, and a little information
about an area allow you to make an informed judgement about where to
draw preserve boundaries.16 Just as importantly, however, we must
remember how little information our initial decisions are based on
and jump at the chance to change them as new information becomes
available.
- Nodes, networks, and MUMs
- An approach to designing systems of reserves to enhance the
effectiveness of the ensemble [8]
- Node--An area with an unusually high conservation value.
- Network--A system of corridors to allow movement among
nodes, since nodes will rarely be large enough to allow persistence
of low-density organisms.
- MUMs (Multiple Use Modules)--A central, well-protected core
surrounded by areas of increasingly greater human impact.
Let's return to the five-step process I outlined earlier:
- What are the elements of concern?
- Where are the elements of concern found?
- How large must the preserve be to serve its purpose?
- What features of the preserve must be protected/managed to allow
the elements to persist in the area?
- How large a buffer zone is required to prevent/reverse
degradation of the primary habitat?
You'll notice that the abstract ideas I talked about a few minutes ago
acutally play very little role in this list. What that suggests to
me, however, isn't that the abstract concepts are useless. If they
were, I wouldn't have troubled you with them. What it suggests is
that problems are often site-specific (and taxon-specific) and that
concrete applications of the abstract concepts will depend on those
site-specific features. Furthermore, most of the questions that must
be answered during the course of putting together a reserve design
must be answered with very little information available. Still, there
are several important things to realize:
- The reserve design is never fixed--or at least is
should never be fixed. It should always be open for
amendment and improvement as new information becomes available. New
threats to the primary habitat may require larger or more
stringently enforced buffer zones. Unexpectedly vigorous population
recoveries in target species may lessen the need for interventionist
management and monitoring.
- Even though decisions about reserve boundaries often seem
arbitrary and ill-founded--Should we draw the line up this
ridge or that ridge?--the results are based on such fundamental
properties--soil types and distribution, geological and
hydrological features, the geographical location of known
populations of species of concern--that even if we were to
study an area in detail for fifteen or twenty years, the eventual
boundaries that we drew would likely be almost identical to those
that we draw based on our ``gut'' feelings. After all, those gut
feelings integrate a lot of knowledge and understanding of
the natural world--knowledge and understanding that we too
often underestimate and undervalue.
Next: Bibliography
Up: Implications of Island Biogeography
Previous: The SLOSS debate
Kent Holsinger
2011-11-06