M1: Introduction to
Conservation Area Networks
Learning Objectives: This module is
an introduction to the key concepts of biodiversity, conservation areas,
systematic conservation planning, and to the software used for planning. Learners will draw on some previous
knowledge of ecology and conservation biology.
Biodiversity
is the variety of living features and processes at all levels of structural,
taxonomic, and functional organization. Biodiversity includes all diversity of
life that exists on Earth.
Biodiversity processes include endangered biological phenomena such as
species' migrations endangered by the building of fences and roads.
Biodiversity does not include ecosystem services (e.g., nutrient cycling,
the movement of water or energy) or culturally-based categories (e.g., cultural,
spiritual, or aesthetic objects) though it does not deny their importance.
Planning for biodiversity conservation assumes that it is desirable (or
good) to preserve biodiversity.
Conservation
biology assumes that all components of biodiversity are important, not just
charismatic species (animals that have great popular appeal).
Environmental ethics seeks to delineate the reasons for the conservation of
biodiversity.
Biodiversity
conservation has become important because human beings today are believed to be
causing extinctions at a rate unprecedented in human history.
Biodiversity can be measured in a variety of ways, depending on the purpose
of the measurement.
Ecologists
distinguish between:
Alpha diversity - diversity within an area;
Beta diversity - diversity between areas;
Gamma diversity - total diversity of a region.
Biodiversity has been measured by:
Species
richness: this measures the total number of species (or other biota) in an area. This particular measure of biodiversity
is
not used in systematic conservation planning.
Habitat/ structural diversity: this measures biodiversity through the
diversity of composition or spatial configuration of habitats, the diversity of
age classes (e.g., old vs. young trees), etc.
Functional and process diversity: biodiversity is measured using disturbance
types and frequencies (e.g., fire regimes), seasonal migrations of animals, etc.
Complementarity is a measure of what new biodiversity features a new
area brings relative to a group of already selected areas; Complementarity is
thus a measure of beta diversity, measuring what is different about the
new area.
The measure of complementarity is specific to systematic conservation
planning.
Complementarity is a measure of the contribution that an area in a planning
region makes to the full complement of biodiversity features (e.g., species).
In systematic conservation planning, it refers to the relative contribution
an area within a larger region makes toward a particular conservation
goal. For example, if a particular area has few species that do not
occur widely in the conservation planning region, it may have higher
complementarity than an area with many species that are widespread
throughout the planning region. In other words, an area has high
complementarity if it has a large number of unrepresented species
relative to other areas in the planning region.
Complementarity supersedes (or preferentially replaces) other measures of
biodiversity only in systematic conservation planning.
The use of complementarity allows the representation of all species in as
few areas as possible. The
concept of complementarity will become more familiar as we examine the
methods of systematic conservation planning.
For more on complementarity see M8: Place
Prioritization.
Conservation Areas: These are geographically delineated terrestrial or
marine regions (places) managed for the persistence of biodiversity features
(taxa, communities, habitats, etc.) and processes.
Conservation
areas include but are not limited to traditional reserves and national parks.
"Conservation area" replaces "reserve" because the name change is politically
significant. A reserve that excludes human habitation
or extractive use is but one in a continuum of different management options.
Empirical studies must be used to determine whether or not a
particular management option is adequate for the persistence of biodiversity in
an area.
"Site"
is sometimes used to refer to a place (or area) being analyzed for
conservation action.
|
Example 1.1
IUCN
Classification of Protected Area Management Categories
The IUCN
(World Conservation Union) is the world's largest conservation network
and is comprised of scientists, governments, conservation experts, and
non-governmental organizations from around the world. In order to
implement effective conservation management and planning, the IUCN
classifies protected area management into 6 categories with specific
objectives, guidelines and responsibilities for each protected area:
I.Strict
Nature Reserve/ Wilderness Area: a protected area managed mainly for
science and wilderness protection. A protected area managed mainly for
science is defined as an "area of land and/ or sea possessing some
outstanding or representative ecosystems, geological or physiological
features and/ or species, available primarily for scientific research
and/ or environmental monitoring." A protected area managed mainly for
wilderness protection is defined as a "large area of unmodified or
slightly modified land, and/ or sea, retaining its natural character and
influence, without permanent or significant habitation, which is
protected and managed so as to preserve its natural condition."
II.National Park: a protected area managed mainly for ecosystem
protection and recreation. This area is defined as a "natural area of
land and/ or sea, designated to (a) protect the ecological integrity of
one or more ecosystems for present and future generations, (b) exclude
exploitation or occupation inimical [detrimental] to the purposes of
designation of the area and (c) provide foundation for spiritual,
scientific, educational, recreational and visitor opportunities, all of
which must be environmentally and culturally compatible."
III.Natural Monument: a protected area managed mainly for conservation
of specific natural features. This is an "area containing one, or more,
specific natural or natural/ cultural features which is outstanding or
[of] unique value because of its inherent rarity, representative or
aesthetic qualities or cultural significance."
IV.Habitat/ Species Management Area: a protected area managed mainly for
conservation through management intervention. This protected area is an
"area of land and/ or sea subject to active intervention for management
purposes so as to ensure the maintenance of habitats and/ or to meet the
requirements of specific species."
V.Protected Landscape/ Seascape: a protected area managed mainly for
landscape/ seascape conservation and recreation. This is defined as an
"area of land, with coast and sea as appropriate, where the interaction
of people and nature over time has produced an area of distinct
character with significant aesthetic, ecological and/ or cultural value,
and often with high biological diversity. Safeguarding the integrity of
this traditional interaction is vital to the protection, maintenance,
and evolution of such an area."
VI.Managed Resource Protected Area: a protected area managed mainly for
the sustainable use of natural ecosystems. This area contains
"predominantly, unmodified natural systems, managed to ensure long term
protection and maintenance of biological diversity, while providing at
the same time a sustainable flow of natural products and services to
meet community needs."
|
Conservation Planning Goals:
The two major goals
are the
representation and persistence of biodiversity within
Conservation Area Networks (CANs).
Another goal is economy or the cost-effectiveness of a plan. Conservation planning attempts to make
the cost of a plan as little as possible.
It is common practice to establish conservation areas on land with little
economic value. Gaps in the
Conservation Area Networks (CANs) are therefore often in economically productive
areas or close to urbanization. In
these areas, species then compete with human populations for natural resources.
Conservation
planning must incorporate socio-political, economic, and other such factors,
besides purely biological ones.
Conservation
planning must be systematic: traditional
ad hoc
(improvised or used for
specific/ immediate problems/ needs) methods lead to inefficient deployment of limited
resources (Pressey 1994).
|
Example
1.2
Pressey's Review of Ad Hoc Reserves
(Pressey 1994)
As stated earlier among the goals of conservation planning, conservation
areas such as reserves should provide as much of a complete representation
of biodiversity within a region as possible.
Pressey shows that decisions in conservation planning often depend on
demands of the moment or other particular purposes (most often not with the
representation of biodiversity in mind):
"The resources for conservation are limited and activities that are
destructive to nature are expanding. The
success of eventual reserve networks in representing the elements of
biodiversity will therefore depend largely on how carefully the individual
reserves have been located (663)." Achieving this goal is a driving force of
Systematic Conservation Planning.
Pressey classifies the types of ad hoc
reserves as: "lands nobody
wanted" - e.g., unsuitable for agriculture, mining, forestry, and commercial
development; or reserves for reasons not associated with biodiversity -
recreational value, beautiful scenery, potential for tourism and revenue,
originally set aside for private hunting, preventing soil erosion into
agricultural lands, etc. These biases
of
ad hoc reservation design cause concern over what Pressey calls "the
uncertain fate of the unreserved natural features. . .Once they disappeared,
declined, or degraded the potential to protect their biodiversity is forgone
or reduced (664)." Populations
such as metapopulations (a population of species consisting of
subpopulations linked by immigration and emigration) occupy a habitat matrix
(a mosaic of habitat patches across which organisms move, settle, reproduce
and eventually die.) This matrix consists of suitable and
unsuitable patches. If biased ad
hoc
reserves lead to the division of habitat matrices, this will cause species to
decline. Moreover, in many cases
conservation planning algorithms (such as those used in systematic
conservation planning), which are designed to protect the minimum total
reserve area needed to represent biodiversity features, demonstrate that
fewer areas are needed to represent all biodiversity features than in ad
hoc reserve networks, thus decreasing cost of potential reserves.
|
Systematic Conservation Planning is the selection of
biodiversity conservation area
networks (CANs) and the formulation of management plans for these networks,
using explicit step-wise protocols.
The main
purpose is to identify priority areas for biodiversity and separate them from
processes which threaten their persistence.
It is a
structured step-wise approach with several stages with feedback, revision, and
reiteration, where needed, at any stage.
Systematic
Conservation Planning is usually implemented with software tools using
electronic geo-referenced data sets and area selection mathematical algorithms.
Under the
umbrella of systematic conservation planning is
conservation assessment, a
term used to refer only to assessment of the potential value of conservation
areas. Such assessment is a necessary stage for
the selection of CANs (see
M7: Review Existing Conservation Areas).
|
Example
1.3
Kirkpatrick's Plan for Tasmania
(Kirkpatrick 1983; Justus and Sarkar 2002)
Kirkpatrick provided a plan to conserve the
biodiversity
of Tasmania that involved the first use of
complementarity. This makes it one of the most significant
developments in the history of systematic conservation planning.
Kirkpatrick searched for unreserved and badly reserved populations of 34
vascular plant species endemic only to
Tasmania. The endemics already adequately
reserved in Tasmania came from
previous examples of ad hoc reserves, as they are found mostly in
western and montane regions in scenic national parks.
Kirkpatrick pointed out that the
non-iterative procedure (just using species richness as a
factor) for place or region selection in a CAN was inefficient.
He shows that a non-iterative procedure would have been inadequate in
achieving biodiversity representation while minimizing the amount of
conservation sites:
"A major drawback of a listing of priority areas on the basis of a single
application formula is that there is no guarantee that the priority area
second or third on the list might not duplicate the species, communities,
habitats that could successfully be preserved in the first priority area
(Justus and Sarkar 2002, 128)." The
non-iterative procedure would have over-represented some species and
possible under-represented many other species.
This is unacceptable in planning conservation area networks.
Kirkpatrick then used an iterative procedure combined with an implicit
notion of complementarity.
Complementarity was measured at each step of the
iterative planning procedure as the number of unrepresented
species (Margules and Sarkar 2007).
If a particular area has few species that do not occur widely in the
conservation planning region (CAN), it may have higher complementarity than
an area with many species that are widespread throughout the planning region
(CAN). Kirkpatrick began by giving numerical values of 100, 50, or 0
to species depending on their presence in conservation areas. The value a
species receives depends on complementarity. As Kirkpatrick puts it: "Thus,
species, communities or habitats that had high weightings because of their
poor preservation status, and that are in the first priority reserve, will
not merit the same weightings in the selection of a second priority reserve. Thus, in the first round the presence of a
particular species may add 100 to the value of a site, because the species
was totally unpreserved. In the second
round the same species could only be worth 50 because it is now within one
notional reserve. If this
species also occurs in the second priority area, its worth in the third
round could be assessed at zero (Kirkpatrick 1983, 128)." (The
numbers are arbitrary, but the use of complementarity is clear.)
The unreserved/ badly reserved species turned out to be located in
areas of low to non- existent agricultural grazing and intense fire regime
presence. Seven small regions were required
to represent all species in the network.
|
For effective
protection of nature, biodiversity conservation must be accompanied by
sustainable natural resource management and ecological reconstruction.
Sustainability is needed to ensure
that future generations may lead lives of acceptable quality. In particular, the health of future
generations must not be compromised because of the over-consumption of the
present generation.
Ecological reconstruction (also
called restoration in many contexts) is necessary because many areas of the
world have been biologically degraded by human activities.
