Conservation Tools

Contents of Main Description

   Introduction
   Traditional or Informal Prioritization Approaches
   Formal Prioritization Systems
   One Typical Approach to Prioritization
      Determine Scope
      Develop Value Hierarchy
      Value Hierarchy
      Swing Weighting
      Project Identification
      Specify Performance Measures
      Establish Utility Functions
      Scale and Utility Function for Biological Value
         Example of Scales for a typical conservation project ranking system
         Scoring System
      Score and Rank Projects
      Conduct Sensitivity Analyses

Introduction

Prioritization tools are gaining greater recognition and acceptance as more conservation practioners realize that “ad-hoc” or “opportunistic” resource protection may not ensure sustainable protection of the regional resource base. Ecosystem functions and services can be significantly impaired if a basic functional core or network of function is not protected or is too fragmented to function properly.

There are a wide variety of “off-the-shelf” prioritization or “decision-support” tools available. Many relate to specific conserv ation resources; a few attempt to combine many resources in one index or measurement system.

An example of a relatively “simple” prioritization tool or decision-support system is the global and state rarity assessments for endangered rare or threatened species, as determined by the Natural Heritage Programs (see www.naturalheritage.state.pa.us or www.natureserve.org), or by the Vista software program, promoted by NatureServe (www.natureserve.org/prodServices/vista/overview.jsp).  An example of a more complex prioritization system is SmartConservation^® (www.smartconservation.org). A list of currently available prioritization tools for Pennsylvania users is provided below in the “Related Library Items” section of this overview.

Traditional or Informal Prioritization Approaches

Traditional prioritization approaches range from reliance on intuition to structured project rating systems. Importantly, these traditional or informal methods can, under certain circumstances, yield correct outcomes.  However, they are typically compromised for a number of reasons including: 

• Misalignment with organizational objectives and priorities
• Flawed logic (e.g., undue attention to the “squeaky wheel” or fair sharing)
• Absence of ways to demonstrate inclusion of public input
• Inability to revise with changes in circumstances
• Failure to demonstrate consideration of project synergism or alternative project packaging.>

Such prioritization failures have always been a source of concern. However, as the stakes rise, both in terms of the cost of capital projects and the requirements for cost-effectiveness to be competitive, use of proven, formal prioritization systems is warranted.

Formal Prioritization Systems

Priority systems have three primary elements: performance criteria (often in the form of scales), procedures for applying these performance criteria, and decision rules. Formal priority systems require that these elements be employed in mathematically correct, logically consistent methods to ensure the validity of rankings. In so doing, the failures of informal approaches are avoided.  Perhaps most importantly, formal priority systems require implementation of structured decision processes that systematically review each project’s potential performance. 

The benefits of a formal priority system are as follows:

• Aligned with the mission of the organization
• Understandable to decision-makers by converting values into measures
• Objective by consistently showing the relationship of value to rank
• Credible and transparent
• Replicable by others
• Defensible in that the mathematical logic is correct
• Useable in that projects of different orders of magnitude are not compared
• Able to be used in a cost/benefit format if needed

The specific steps involved in the construction and implementation of a formal priority system and the advantages over informal systems that these steps address are outlined in the table below: 

Table: Priority System Development Steps & Advantages

Step	Description	Advantage
Determine Scope	Define level and breadth of analysis required to address prioritization needs	Solving the correct problem, appropriate resource use, understanding of issues
Develop Value Hierarchy	Graphical representation of organizational objectives and performance criteria	Alignment of organizational objectives
Swing Weighting	Assignment of relative weights to organizational objectives and criteria	Consistency with values of organization; articulation of importance of objectives
Project Identification	Listing of potential projects	Avoids “pet” projects or projects to address squeaky wheel
Specify Performance Measures	Measures are determined using natural or constructed scales that indicate the relative performance of projects in achieving objectives	Establishes precise, structured basis for project evaluation consistent with organizational objectives
Establish Scales	Provide for non-linear accrual of benefits given incremental change in project performance	Avoids logic failures resulting from inadequate consideration of scales of measurement
Score and Rank Projects	Use performance measures to score projects based on criteria	Provides for auditable, transparent ranking
Conduct Sensitivity Analysis	Examine changes in project rankings given changes in weightings and project scores	Verification and demonstration of consistency of rankings with objectives

 

One Typical Approach to Prioritization

Following is a description of one defensible approach to developing priorities for protecting a multiple resources. It is not the only approach.  Other examples may be available on the web. “Off-the-shelf” prioritization systems that address specific environments (e.g. watersheds, rare species, etc.) may also be available. The following method has been developed by the National Audubon Society for Important Bird Areas and has been modified for use by small to midsized land trusts.

Determine Scope

Establishing the scope and level of analysis of a priority system, like other complex projects, involves properly framing the decision problem and determining the analytical results that will address this problem.  For a resource protection prioritization, this requires an assessment of:

• how projects are defined (e.g., habitat, species or multiple species protection);
• whether certain projects may be exempted from evaluation (e.g., certain properties within the area of interest already may be dedicated for purchase by the state or other conservation organizations or may be donated in someone’s will.); and
• funding alternatives (i.e., partial funding  for easements vs. full funding for purchase).   
• Additionally, consideration must be given to the criteria used to distinguish between capital and operating budget investments.  Prioritization normally relates to one or the other  of specifies inclusion of both.  

Develop Value Hierarchy

To ensure consistency with budgeting practices, but more fundamentally, with organizational objectives, the second step in constructing a priority system is the development of a “value hierarchy”.  A value hierarchy is simply a graphical representation of organizational objectives and the performance criteria used to evaluate achievement of these objectives as shown below.  However, a well-constructed value hierarchy has several characteristics that are frequently violated in informal ranking systems.  In particular, a value hierarchy should contain objectives that are fundamental, non-redundant, and independent to ensure mathematical validity of priority calculations.  Fundamental objectives are those that define the mission of the organization; they articulate what is important for the organization to accomplish.  Non-redundancy requires that objectives do not address effectively the same or overlapping aspects of organizational performance.  Independence of objectives ensures that accomplishment relative to one objective is not, in effect, dictated by the accomplishment of another objective.  These requirements ensure that the benefits assigned to objectives in the value hierarchy are not double-counted and are additive. 

Beyond fundamental objectives, a value hierarchy will also display “means objectives” or performance criteria for each fundamental objective.  While certain fundamental objectives inherently define performance criteria, this component of the value hierarchy ensures a clear articulation of how fundamental objectives are accomplished.  In so doing, evaluations of project performance will necessarily be based on performance that addresses organizational objectives. 

Value Hierarchy

Swing Weighting

While each of the objectives identified in the value hierarchy are “fundamental”, each are not equally important.  Nor are the criteria used to define accomplishment of each objective.  Accordingly, weighting of objectives and criteria is necessary to properly reflect organizational values.  This weighting process is perhaps the most frequently abused aspect of those informal approaches that attempt to prioritize projects based on some structured rating system.  Swing weighting requires particular attention to several details to retain the mathematical validity of prioritization results.  For example, it is important that weights reflect tradeoffs between objectives as shown below.  Weightings cannot be simply a numerical translation of: “Very Important, Sort of Important, Who Cares?”.  Rather, the weights assigned to objectives must reflect the desirability of one objective relative to other objectives.  Therefore the scales used to define performance must reflect real rather than abstract trades.  Swing weights are assigned to specific ranges of performance through a pair-wise evaluation of tradeoffs (i.e., amount of A required to trade for a unit of B). Swing weightings reflect policy decisions and therefore, formal priority systems require an explicit definition of policy-makers’ values with respect to tradeoffs among objectives. (This auditable aspect of formal priority systems can be the most welcome (or unwelcome) feature of the analysis.  Because the nature of the swing weighting requires explicit valuation of tradeoffs, it uncovers logic that may be shrouded in informal approaches.)

Weighting of objectives reflects the relative importance of each objective to the organization’s mission.

Points

Habitat Size                            15

Habitat Type                           15

Threat to Resource                10

Special Features                    10

Local Economy                      10

Public Access                        10

Ownership Pattern                 10

Landowner Interest                10

Cost                                        10

                                                                       100

Project Identification

Though all prioritization processes, formal or not, rank from a set of candidate projects - many of which will be defined in advance of the prioritization exercise - the process of developing and weighting objectives and criteria may result in revisions to the candidate project listing.  In addition, this process may serve as an effective project screening vehicle in that it will require that candidate projects be evaluated to determine if sufficient information on the project is available to effect a meaningful evaluation.  This alone will limit consideration of ill defined, tenuous, or “pet” projects.  It can also serve to facilitate re-definition of projects, or construction of projects that are more consistent with organizational objectives.

Projects are often bundles of properties.  The closer the projects are in size, the easier it is evaluate them.  For example, comparing projects of 5 to 10,000 acres is much more difficult then projects of 50 to 500 acres. 

Specify Performance Measures

This redefined set of candidate projects are prioritized according to the extent to which they contribute to achievement of the organization’s fundamental objectives.  This requires establishing measures of project performance for each fundamental objective identified in the value hierarchy.  These measures may employ “natural” or “constructed” scales.  Natural scales are used where direct measures or data on project performance are available.  For example, a natural measure of forest value is size—bigger is better.  The scale must consider minimum size and acreages that provide  significant habitat value.  Constructed scales, in contrast, are used when direct measures of project performance are not available.  These scales, usually in the form of a narrative description of performance with reference to specific criteria, must provide precise, unambiguous definitions of project performance.  The shape of forest areas—round, long and skinny may affect species types and disturbance.  Shapes with long edges allow for light penetration, invasive species and predation.  Both forms of performance scale must identify the full range of project performance and collectively define the basis for evaluation and prioritization of the candidate projects.  Scales are usually measured from a rating of 0-10 with 10 being the best.

Establish Utility Functions

As part of the performance measurement process, but a step rarely given adequate consideration in informal prioritization systems, is the explicit recognition that benefits often do not accrue linearly.  For example, the benefit of forest size has a minimum of 200 acres for raptors and other small mammals. Smaller area will not allow for sustainable breeding populations due to nest predation.  Once the area gets to be larger than 2000 acres, each extra acre may have a diminished impact on population dynamics.  Though a natural scale may accurately measure project performance, the interval or ratio relationship between points along the scale help measure relative project benefit.  These relationships are expressed as equal intervals or straight lines or varying intervals creating steps or curves as shown in the graph below.  The rate of change between D and C is different then between C and B.   

Scale and Utility Function for Biological Value

 

Example of Scales for a typical conservation project ranking system

Mission Statement

Enriching the lives of all citizens by maintaining our rural character and local economy through preserving,  protecting and enhancing  natural systems and encouraging  land stewardship to ensure quality water and water supply, sustainable habitats, flood protection, carbon sequestration and all forms of sportsmen activities, wildlife watching and outdoor recreation.

Scoring System

This scoring system is to be used by the Board and staff to assist in deciding the dollar amount to offer a land owner for a conservation easement.   It also helps to rank nominated natural areas.

Public Benefit

Habitat size (15 points) - The score measures the sustainability of breeding bird populations for forest interior birds as a surrogate for healthy ecosystems.

1. Large parcels of woodland over 1,000 acres  Or wetlands over  10 acres = 10
2. Four or more  wooded  areas over 250 acres within 100 yards of one another Or wetlands  between 5 and 10 acres  =  8
3. Single  wooded areas over 500 acres or 3-5 acres of wetland =  5
4. Single wooded areas over 250 acres or  2-3 acres of  wetlands = 3
   

Habitat Type/Species (15 points)

1. Threatened or endangered species National or state list) = 10
2. Species in decline = 8
3. Maintain know key species /ecologically significant habitat = 5
4. Multiple species habitat = 3 

Special Features (15 points) - factors that provide added value

1. Groundwater protection = 10
2. Adjacent  to stream = 8.5
3. Scenic value = 7.5
4. Meadow = 4
   

Local Economy (10 points)

1. Fishing, Hunting, Wildlife Watching = 10
2. Hiking, Biking, Kayaking =  7
3. Camping =  1

Public Access/Education (5 points)

1. 1,000 feet of road frontage = 10
2. 500- 1,000 feet of road frontage = 8
3. 499 or less of road frontage = 6
4. No road frontage = 1 

Threat (10 points) - Concern over speed of growth pressure

Proximity to major growth area and water and sewer infrastructure

1. Adjacent  to major growth area = 6
2. Within ½ mile of major growth area = 6
3. Within 1 mile of a major growth area = 6

Feasibility

Number of Landowners (10 points)

1. one =  10
2. two =  8
3. three = 3
4. four plus = 0

Landowner Interest (10 points)

1. Land owner is committed to land protection and an easement = 10
2. Land owner is interested = 8
3. Land owner has no know interest =  4
4. Land owner has no interest = 0

Cost (10 points)

1. Bargain sale =  10
2. Market =  8
3. Above market =  1

Score and Rank Projects

Following construction of each of these elements of the priority system, the physical process of project prioritization is relatively straightforward.  Each project or group of properties is scored on its performance on each of the objectives included in the value hierarchy.  The objective weight is multiplied times the scale rating to provide a criteria score. Criteria scores are summed to give a total score.    Because objectives are independent and non-redundant, these measures of benefit may be added across objectives to yield a measure of total benefit or utility.  Projects are ranked based on the sum of the scores.  While care must be taken in the use of these rankings for project selection, these results provide clear guidance on the relative merits of candidate projects. 

				Criteria Scores
Conservation Sites
			Habitat	Habitat	Threat	Special	Local	Public	Transaction	Landowner	Cost
			Size	Type		Features	Economy	Access	Difficulty	Interest
1	Big Creek		9	3.5	1	6	9	6	3	6	10
2	Little Creek		3	7.5	3	10	9	10	2	8	10
3	Green Hill		9	2.5	1	10	10	10	6	8	10
4	Bills Swamp		8	5	5	8	9	7	10	7	10
5	Diane's Lane		10	7	6	8	9	6	10	7	4
6	Kickapoo Ridge		9	8	3	8	9	6	8	6	8
7	Blueberry Hill		6	2.5	1	6	10	6	5	6	8
8	Hawk Watch		10	10	8	10	10	8	8	10	10
9	Deer Run		10	6	8	10	10	3	4	5	10

An excel model of this prioritization tool is available for download in the library items.  

Conduct Sensitivity Analyses

A sensitivity analysis tries to identify what source of uncertainty weights more on the study's conclusions.Results can and should be tested to examine the relative importance of each criteria to project rankings. The histogram showing the relative contribution of each criteria to the overall ranking is helpful in this step. Finally, sensitivity analysis results help demonstrate the alignment of criteria with an organizations mission.

Contribution by major criteria illustrating the relative importance of each criteria in overall project ranking .

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