I work with a group of colleagues here at BU and amongst a network
of environmental scholars. Our work might be best characterized as the
creation of an aquatic equivalent to landscape ecology, and addresses many
of the questions that you raise. Here are some preliminary thoughts.
First, it is not as wise to try and "manage biodiversity" as it is
to reduce human activities that compromise or reduce it. This is much more
realizable and the benefits are relatively fast and tangible. The best
approach is probably:
1. Develop a graphic database for ecological assemblages on a watershed
basis. The GIS layers can be set up various ways, but you somehow need to
cover species with strictly aquatic, strictly terrestrial, and amphibious
life histories. In forested areas, a very large group of organisms are in
the last category.
Phytogeography, soils, hydrology, climate, the usual list that you
have, are essential for most of the sorts of questions, status, and trends
tasks that you will encounter. In New Brunswick you should conduct an
exhaustive biodiversity survey at the species level as a start. The
characterization of population structure will eventually prove necessary
for some taxa, but this should be pursued in a surgical, cost-efficient
manner when the questions are focussed. Having a handle on nutrient
dynamics is crucial in most areas subject to human disturbance.
The best predictors of aquatic community structure are suites of
organisms that represent fundamental phase states for any given habitat.
In plain English, this means that it is important to know if, say, ponds
have high transparency and well-developed submerged macrophyte communities,
or if they are subject to massive phytyoplankton blooms and have relatively
sparsely vegetated littoral zones, or else heavy growths of water lillies,
the other two littoral phases you'd be likely to encounter. Another
possibility is that variation in pH and tannins might set up
differentiation into blackwater oligotrophic vs. clearwater mesotrophic vs.
turbidwater eutrophic situations. The possibilities are theoretically
endless, but within any one region there are usually only a few major
thrusts of environmental degredation, the monitoring of which might lead to
substantial improvement in water quality, wildllife value, or the strength
of fishery or forest resources.
3. Once you have established the capacity to recognize shifts in the
biological functioning of your watershed(s), and there is a decent data
base on current conditions, the next step is to establish alternative
scenarios: i.e., define reasonable objectives for resource extraction and
land use both in terms of degrees of impact and spatial distribution. One
assumes that when intentions are good, this map will incorporate knowledge
of the distribution and habitat requirements of endangered taxa and
biological communities, and avoid harming them.
4. The next step is to assess the demands being placed on the landscape
(including the aquatic compartment) for ecological services: e.g., clean
water, a certain productivity of game or timber, and so forth. Extracting
these services will exact a cost to the system. The goal is to establish
levels and distribution patterns for extraction and disturbance that are
within the capacity of the watershed ecosystem to sustain.
5. The fact is that we really do not know very well how to do step #4, and
the answers are often very case-specific. So a good move is to set up a
system of experimental management areas, usually centered around nodes of
human habitation, or discrete communities. The people living in these
communities should be the ones making the decisions, of course, but it
doesn't always work out that way. In any event, "management" and "control"
areas are set up in as statistically auspicious a manner as is possible,
and you go ahead with the chosen management strategy while closely
following the behavior of the system. At regular intervals (yearly is good
at high lattitudes) you see if the human demands on the system are or are
not causing signs of system failure, such as extirpations or extinction,
reduction in wildlife populations, loss of particularly vulnerable
organisms such as large carnivores, etc.
6. Often it is possible to set specific restoration goals as part of the
general objectives. In your area, I would assume that maintenance or
facilitation of the reestablishment of native-run salmoniform populations
would be a part of any plan.
When the community makes its decisions about the future, it has to
be kept in mind that maintenance of intact ecosystems and maximization of
game are overlapping objectives, potentially, but the area of overlap is
not huge. It is necessary to consider other values, such as scenic,
recreational, and ethical. That last one is always difficult to bring to
the table, but it is probably the most important one of all.
Of course, the answers to your final questions, the "do we's" is,
no, not often or particularly well. But things are changing slowly for the
better.
Les Kaufman
Boston University Marine Program
Department of Biology
Boston University
5 Cummington Street
Boston, MA 02215
e-mail: lesk at bio.bu.edu
phone: 617-353-5560
fax: 617-353-6340