Viability assessment begins by identifying key ecological attributes (KEAs) for each of your focal conservation targets. At its most basic, a key ecological attribute is an aspect of a target’s biology or ecology that if present, defines a healthy target and if missing or altered, would lead to the outright loss or extreme degradation of that target over time. For example, a key attribute for a freshwater stream target might be some aspect of water chemistry. If the water chemistry becomes sufficiently degraded, then the stream target is no longer viable. Key ecological attributes can often be grouped into three classes:

• Size is a measure of the area or abundance of the conservation target’s occurrence.
• Condition is a measure of the biological composition, structure and biotic interactions that characterize the occurrence.
• Landscape context is an assessment of the target’s environment including ecological processes and regimes that maintain the target occurrence such as flooding, fire regimes and many other kinds of natural disturbance, and connectivity such as species targets having access to habitats and resources or the ability to respond to environmental change through dispersal or migration.

However, not all classes necessarily apply to all focal targets.

Although key ecological attributes are specific descriptions of an aspect of a target, they are generally still too broad to measure or assess in a cost-effective manner over time. To this end, it is important to develop indicators that can be used to assess the attribute over time. An indicator, in simplest terms, is what you measure to keep track of the status of a key ecological attribute. For example, as shown in Box 1, an indicator of fire regime for a grassland target might be years between fires, while an indicator of population size for a migratory fish target might be the number of spawning adults observed per hour during the breeding season. Generally speaking, an indicator may be either:

• a specific, measurable characteristic of the attribute such as the total number of adults in a population;
• a collection of such characteristics combined into an index such as a multi-species index of forest canopy composition

Key ecological attributes and their associated indicators provide a way to assess the status of a target over time. But by themselves, they are not sufficient to determine the health of a given target. Instead, they need to be placed in an appropriate context or frame of reference. Just as a healthy person’s pulse rate or blood pressure changes over the course of a day and over a lifetime, most key ecological attributes will vary over time. For example, the size of migratory fish population might go up and down on a year-to-year basis. As shown in Figure 1, however, there is a difference between a population size that is within the acceptable range of variation (ARV) and one that is outside this acceptable range. For some attributes, this acceptable range is one-sided (for example, it may be possible to have too little, but not too much of a particular kind of forest within a project area).  For other attributes, the acceptable range is two-sided (for example, there can be too many or too few deer per hectare in the forest). In some cases, we may be able to precisely determine thresholds that clearly mark the boundary of this acceptable range, whereas in other cases we can only approximate where these thresholds might be. These thresholds, however, establish what you determine as the acceptable range of variation for your target

Estimating the acceptable range of variation for each key attribute helps answer two crucial questions: how much alteration of a key attribute is too much? And, how much restoration is enough? Managing conservation targets within their acceptable range of variation in turn does not mean managing for all the variation that the target might experience under undisturbed conditions. Instead, it means managing only for an envelope of conditions that together are “enough” for target persistence and function[2]. 

Once you have estimated the acceptable range of variation for an attribute, you can then go on to specify the viability rating scale. This scale involves establishing the following boundaries for an indicator based on your thresholds:

• Very Good – Ecologically desirable status; requires little intervention for maintenance.
• Good – Indicator within acceptable range of variation; some intervention required for maintenance.
• Fair – Outside acceptable range of variation; requires human intervention.
• Poor – Restoration increasingly difficult; may result in extirpation of target.

In effect, by establishing this rating scale, you are specifying your assumption as to what constitutes a “conserved” target versus one that is in need of management intervention. This rating scale is directly analogous with the established pulse rate and blood pressure ranges that a doctor uses to determine whether a patient’s circulatory system – and thus by extension the entire patient – is healthy.  Although ideally you would define all four boxes of the rating scale, in many projects, you may find that you can only define one or two key boxes – for example the threshold between fair and good – especially in early stages of your work.

The final step in the viability assessment is to use the rating scale that you have constructed and available evidence and/or expert opinion to determine the current status of your conservation target (where your target is today) and the desired status of your target (where you would like it to be at some point in the future). This desired status becomes a goal for your project.

Although the viability assessment process can seem complex and overwhelming, at its core, it is merely a way to use your best available knowledge to provide a consistent framework for defining and then measuring the health of your focal conservation targets. In effect, you are constructing a model in which your indicators will tell you about the status of your attributes which in turn will tell you about the status of your focal targets which in turn will tell you about the status of the overall biodiversity of the project site.  If you can say that your indicators are in their acceptable range, then you say that your key attributes are okay, which in turn means your targets are okay, which in turn means the overall biodiversity is healthy. If your indicators are not in the acceptable range or are headed out of that acceptable range, then you have problems that you need to address.

A complete viability assessment involves:

1. identifying the key ecological attributes for a given target;
2. selecting indicators for each attribute;
3. building a rating scale for each indicator based on your hypothesis about its 
    acceptable range of variation;
4. determining the current status and the desired future status of each attribute
    using the rating scale and data on all available indicators,
5. recording any issues, gaps in knowledge, or assumptions,
6. repeating this process for all your targets, and
7. reviewing and adjusting your assessments as necessary.

As you go through this process, keep in mind:

• Your Work Does Not Have to be Perfect – All too often, project teams seem to get stuck on this step in the CAP process because they feel they do not have sufficient information to develop scientifically credible indicators or ratings. The key here is to make the best use of the information you have, document your key assumptions and uncertainties, get started, and move forward. As your knowledge and resources expand and the project progresses, you will be able to refine, expand, and improve your work. DO NOT GET BOGGED DOWN! Do the best you can and keep moving through the process.
• Make Use of Existing Work – Your team is probably not the first group to develop a viability assessment for any given type of target. Before you spend a lot of time and energy developing your analysis, see if you can find existing assessments from other groups that you can adapt to your project’s situation. The Conservation Project Database (http://conservationtools.tnc.org/conpro/) is a good starting point to find these assessments; the references at the end of this chapter provide other places to look.
• This is a Highly Iterative Process – Although viability assessment is presented as a linear series of steps, in reality you will have to go back and forth through these steps, for example revising your indicators and even your key ecological attributes as you start to develop your ratings.

üThe CAP Workbook contains spreadsheets in which to record KEA, indicators, rankings and rationale determined during the viability assessment process.  The Viability Wizard can assist you in entering relevant information.

1. Select a target and identify a limited set of key ecological attributes

Select one of your conservation targets to assess.  If this is your first time doing a viability assessment, you may wish to select a relatively simple and straightforward target. With your team, identify a small set of ecological attributes that are critical to this target’s long-term viability. There is an almost infinite number of attributes that could describe some characteristic of a target. The challenge here is to identify a small selection of critical attributes that if degraded, would seriously jeopardize the target’s ability to persist for more than a few decades. If necessary, brainstorm a list of attributes of the target and then try to winnow them down to the most essential ones. It may also be helpful to develop an ecological model of the target. The broad categories of size, condition, and landscape context can be used to inform the selection of specific key ecological attributes. Box 2 provides a flowchart that can help you in the selection of key ecological attributes.

In identifying your key ecological attributes, it is important to ensure that your final selections are – as the name implies – attributes of the target, rather than descriptions of threats to the target.  For example, “compatible land use” is not a key ecological attribute for a forest target.  Instead, the threat of incompatible land use presumably affects actual key attributes such as connectivity, soil stability, or the hydrologic regime.

The key ecological attributes that you identify for a target actually define the essence of that target.  Often, the process of considering and identifying key ecological attributes will cause you to rethink the target and what it represents.  There may even be occasions where you may decide to rename your target to more accurately reflect the key ecological attributes that define it.

For example, the Chico Basin project team in Colorado has identified the following key ecological attributes for one of their focal conservation targets.

2. Select indicators for each key ecological attribute

For each of your key ecological attributes, determine an indicator that can be used to assess the attribute over time. In many cases an indicator can be the same as the attribute itself. For example, if your attribute is population size, the indicator may be the number of individuals in the population if you can count this number directly.  If you cannot count this number directly, then your indicator will specify how you will measure this number – for example, for a fish population, as catch per unit effort using a specific technique at a given time of the year. In other cases, however, developing a good indicator will require a bit more thinking to find a way of measuring the attribute over time. For example, if your attribute is the water quality of a stream, it is not possible to measure every physical and chemical parameter. Instead, you would select a few representative parameters – for example water temperature and oxygen levels – that you feel can represent the overall water quality.  You can also combine several measurable properties into a composite indicator or index.  Indicators frequently involve some type of quantitative assessment – such as number of acres, recruitment rate, age class sizes, percent of cover, or frequency of fire of a given intensity. Other indicators may involve measurable elements that are not numerical, such as the seasonality of fire or flooding. Box 3 provides some tips for selecting good indicators.

In many cases, you may be able to measure a key attribute using just a single indicator.  However, sometimes there may be no single best indicator so you may need to track several indicators to get a better picture of what is going on. For example, field surveys and analyses of aerial photographs together may provide complementary information on forest tree composition, more accurate and reliable than either one could provide on its own.

In our example, the Chico Basin project might add the following indicators for their targets:

3. Determine acceptable range of variation and rating scale for each attribute

Most attributes vary naturally over time, but we can define an acceptable range of variation. This is the range of variation for each key ecological attribute (or technically for its indicators) that would allow the target to persist over time – a range in which we would say the attribute has Very Good or Good status (see Box 4 for a sample data form and definitions of these criteria). If the attribute drops below or rises above this acceptable range, it is a degraded attribute that has Fair or Poor status. Your challenge is to specify – to the best of your current knowledge – your assumption as to what would constitute an acceptable range of variation. 

Ideally, and over time, you will identify a set of thresholds or boundaries for the four rating increments for each key ecological attribute: Very Good, Good, Fair, and Poor.  These thresholds should state clearly where the indicator being measured would fall within each level of the rating scale. For example, is a “good” size for a grassland a minimum area of 50,000 or 100,000 acres?

The scientific information needed to establish these benchmarks is often lacking or inadequate. In these cases, project teams can rely on general ecological concepts, comparisons to other similar systems, well-informed expert opinion – or failing that, the team members’ best estimate – to determine a “credible first iteration” of the benchmarks and assessment of the current rating. For the initial planning, it is often sufficient to describe the benchmarks for Good and Fair, since this distinction is the most important for determining the need for management actions. As shown in the following example, if you treat this as the first step in an iterative process, you can almost always put some initial thinking down.  Identifying gaps and weaknesses in existing knowledge is also crucial to help you spur investigations to improve the state of knowledge about your focal targets.

For example, suppose a project team is working on a project with a grassland target. They decide that one of the key ecological attributes is fire regime and the indicator of the fire regime is fire frequency. They know that the grassland that they are responsible for managing is full of woody species and the grasses and forbs are not flowering well and they haven’t seen some grassland nesting bird species in a few years.  As a result, they are pretty certain that the grassland needs to burn, but they don’t know how frequently the grassland would burn in a natural state. So in their first pass, the team fills out the viability rating scale as follows:

This team has defined Fair as being “fire not frequent enough” and Good as being “fire frequent enough.” This is perfectly acceptable for their first attempt. Later, the team locates a local grassland expert. She tells them that fire should occur every 5-10 years to maintain the structure of this type of grassland. This additional information enables them to fill out the table as:

Reviewing the literature and consulting with experts, the team comes to realize, however, that it is not just the presence of fire anywhere on the site that matters, but that a sufficient portion of the site should burn on a regular interval. To this end, over a few years, the team does some more research about the frequency of fires and they redefine their indicator and ratings as follows:

Any of the above outcomes is acceptable for a first iteration CAP depending on the level of information available.

4. Determine current and desired future status of each attribute

Once you have determined a limited set of attributes and indicators for each focal conservation target and determined the rating scale, the next task is to assess the current status rating and set the desired status rating of the attributes relative to your rating scale. The current status rating describes the indicator rating category where your key ecological attribute is today; the desired status rating describes where you want to be in the future. You should consider the appropriate spatial extent and time frame for achieving the desired status; some changes may require long time periods (50-100 years). If you know the actual specific current indicator status information, record it as well as the desired indicator rating category (e.g., if a Very Good size indicator rating is > 30,000 acres, and you know the current extent is 55,000 acres, record the specific acreage as well as assigning the indicator to the Very Good rating category).

The four-category framework for categorizing the viability status for each KEA and target provides little opportunity to describe and keep track of incremental changes. The ü CAP workbook provides data fields in which you can record information on incremental change in indicators.

5. Record any assumptions

As you go through this work, make sure you write down any relevant issues or comments that emerge. In particular, you should note how you arrived at your viability assessments including references and experts consulted, data analyzed, assumptions you made, your level of confidence in your assessments, and suggested research needs. If you are using the ü CAP Workbook, capture the issues or comments using the comment feature available for many of the key decisions.

6. Repeat for your other targets

Go through Steps 1-5 for your remaining targets.

7. Review your viability assessments and adjust as necessary

Review the results of the viability assessments for all of your targets (if you are using the ü CAP Workbook, the summary page is useful) and discuss with your team. If necessary, you may have to revisit some of your attributes or even your choice of targets. The end product should be a completed viability table as shown in the following example:

Although the viability assessment process has been developed and tested over several years and many workshops, there are still many aspects of the framework that could benefit from further innovation. We offer the following suggestions and encourage you to innovate and communicate additional suggestions:

• Developing general-purpose KEA lists for broad target types. Certain broad types of conservation targets may lend themselves to the development of generic lists or diagrams of KEAs that can serve as templates for use by other projects. For example, river ecological systems invariably call for the recognition of KEAs related to the hydrologic regime, water quality, channel and bank morphology, up-downstream connectivity, and usually river-floodplain connectivity as well. When you develop lists of KEAs for particular target types, you should bear in mind that your work may provide examples for others; and teams working on similar types of targets may benefit from cooperating to develop generic lists or templates.  If you develop such a list, consider making that information available to others.
• Working with target function versus viability. It is important to recall the reasons why targets are selected. They matter not only for their own sake, but also to represent various parts of the biological spectrum so that their conservation will provide a safety net for these many other parts as well. We therefore note that there may be a difference between ensuring that a target merely persists, and ensuring that it provides the ecological functions for which it was selected. For example, the population of a keystone predator may be sufficient to allow the population to persist at some minimally viable level, but not sufficient for its predation to significantly affect prey populations. There is much room for innovation to ensure that our “viability assessments” address the ecological function of our targets rather than their mere persistence alone.
• Improving criteria for the Poor/Fair boundary. When we categorize the status of a KEA or a target as Poor, we are saying that the target is in immediate danger of disappearing from the project area within perhaps 15-25 years. A Poor rating is a call to action rather than a failing grade. It should not take into account estimates of whether restoration is feasible – that should come in the assessment of threats and strategies. However, even though intended to be objective, the Fair-Poor distinction nevertheless can involve some subjective decisions based on estimates of the consequences of current conditions and trends. There is a need for more examples of methods for establishing and objectively documenting this distinction.