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Introduction
Principles
Process
Community
For a more detailed discussion of how Silva approaches ecosystem-based
planning, please see the document entitled Ecosystem-Based
Planning-Principles and Process.
Check out some of our completed Ecosystem-based
Planning Projects.
In the Projects section, you will find a brief summary of
each project, links to maps that you can view online, and links
to the library, where you can download the full project reports.
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The Process: Multiple Spatial Scales
SFF's approach
to ecosystem-based planning is applicable at a full range of spatial
scales from large sub-continental and regional landscapes to small
watersheds and individual patches or ecosystem types. In order to
protect ecosystem health and biodiversity at all scales through
time, ecosystem-based planning needs to begin with as large a landscape
as possible to ensure that ecological processes are maintained throughout
the region as planning proceeds to landscapes of multiple watersheds,
to individual watersheds, and eventually to patches or individual
ecosystem types.
Silva develops ecosystem-based plans so that the protected networks
of ecosystems designed at each scale nest within those designed
for larger areas. This approach not only provides for the most effective
way to protect ecosystem health and biodiversity, but also results
in an efficient planning system in terms of data interpretations,
field assessments, map design, and structuring planning tools like
geographic information systems (GIS) and aerial photo interpretation.
The design of protected networks of ecosystems employ the same set
of five primary variables at each spatial scale:
1. Ecological sensitivity
2. Unique or special features
3. Representative features
4. Focal species
5. Connectivity
The expression of each of these five primary variables varies, depending
upon the scale of planning. For example, at the large landscape
level, an entire watershed may be a unique feature, because it is
the last unmodified area with the full range of grizzly bear habitat.
At the patch level, large snags and fallen trees of a particular
species may be unique features. Along with the five primary variables
listed above, each ecosystem-based plan utilizes specific variables
that reflect the characteristics of the planning area and the overall
objectives of the plan.
Designs for protected networks of ecosystems at each scale are developed
from a combination of interpretation of various data bases, field
assessments, and expert opinion. Each design is subject to modification
based upon a field assessment and peer review of the design.
The three primary scales that we employ are described below.
However, there are often intermediate scales, where plans are produced
that fall between these primary scales. The precise structure of
a multiple spatial scale ecosystem-based plan depends upon the ecological
characteristics of the area being planned and the objectives for
the plan.
Sub-Continental & Regional/Large Landscapes: PROTECTED AREAS
NETWORK
A Protected Areas Network (PAN) consists of core reserves and linkages
that provide for connectivity between core reserves, and throughout
the landscape being planned. Core reserves and linkages need to
be spatially well distributed across the planning area, and be inclusive
of the five primary variables listed above.
If the planning area is large, consisting of multiple landscapes,
a PAN may be developed for the entire area, with finer scale PANs
developed for landscapes within the large planning area.
The common scales for analysis and map production of PANs range
from 1:500,000 to 1:200,000.
Landscapes and Multiple Watersheds: PROTECTED LANDSCAPE NETWORK
A Protected Landscape Network (PLN) is designed for a medium-size
landscape that will be modified by human activities. The design
of a PLN is followed by development of human use zones for the landscape
and design of an economy for the planning area.
Considering the five primary variables described above, specific
components of a PLN include:
· old growth or late successional forests;
· riparian ecosystems, from large to ephemeral features;
· wetlands and wetland complexes;
· ecologically sensitive areas;
· naturally rare ecosystem types;
· linkages or corridors that provide connectivity
between and within ecosystems, groups of ecosystems, and ecological
communities;
· ecosystems that provide habitat for rare, threatened,
endangered genetic strains, species, and ecosystem types; and
· ecological communities that are representative of
the landscape.
The common scales for analysis and map production of PLNs range
from 1:200,000 to 1:20,000.
Ecological Communities and Patches: PROTECTED ECOSYSTEM NETWORK
A Protected Ecosystem Network (PEN) is designed at the community
or patch level to maintain ecosystem composition, structures, and
functioning in areas modified by human resource extraction and/or
other forms of human development. The design of a PEN is part of
the development of a prescription for human use in
a particular ecological community or patch.
Considering the five primary variables described above, specific
components of a PEN include:
· large living and dead tree structures
· small ecologically sensitive areas
· ephemeral streams and wetlands
· linkages between structures
The common scales for analysis and map production for PENs range
from 1:20,000 to 1:500. |
