Making Management Decisions

Management decisions must be temporally, spatially, and objective specific. Thus, management and conservation are ultimately conducted at the local level. Specific management activities, although presumably based on scientific knowledge, are conducted within the context of relevant social, economic, and political issues (sensu Brown and MacLeod 1996).

Clearly stated goals and objectives will facilitate management and allow the selection of appropriate tools to accomplish these goals and objectives (Box 1.3). Conversely, selection of goals or objectives that are poorly defined or quantified may actually impede management. For example, use of the term "ecosystem health" implies that there is an optimal state associated with an ecosystem, and that any other state is abnormal; however, the optimal state of an ecosystem must be defined, and clearly stated quantifiable objectives must be developed to achieve that state. Similarly, "ecosystem integrity" (Wicklum and Davies 1995) and sustainabil-ity (Lélé and Norgaard 1996) are not objective, quantifiable properties.

Box 1.3 Applying the appropriate fire regime to meet management goals

Throughout the New World, fire regimes changed dramatically after Anglo settlement in concert with changes in ecosystem structure and function. Many ecosystems formerly characterized by frequent, low-intensity surface fires are now characterized by infrequent, high-intensity fires. Altered fire regimes have contributed to, and have resulted from, changes in ecosystem structure; for example, savannas typified by low-intensity surface fires have been replaced in many areas with dense forests that burn infrequently and at high intensities.

Many managers recognize that periodic fires played an important role in the maintenance of ecosystem structure and function, and that these fires probably contributed to high levels of biological diversity. As a result, precise determination of the presettlement fire regime has become an expensive pursuit of many managers. This exercise often is followed by the large-scale reintroduction of recurrent fires into areas where they once were common, in an attempt to restore ecosystem structure by restoring the fire regime.

Unfortunately, accurate reconstruction of events that contributed to historical changes in vegetation (including interruption of fire regimes) will not necessarily facilitate contemporary management, and rarely will engender restoration of presettlement conditions. Pervasive and profound changes have occurred in the biological and physical environments during the last century or more (e.g., dominance of many sites by nonnative species, altered levels of livestock grazing, increased atmospheric CO2 concentrations). As a result, simply reintroducing periodic fires into areas in which fires formerly occurred will not produce ecosystems that closely resemble those found before Anglo settlement; in this case, understanding the past will not ensure that we can predict the future, and a detailed understanding of past conditions may impede contemporary management by lending a false sense of security to predictions based on retrospection. Rather, recurrent fires in these "new" systems may enhance the spread of nonnative species and ultimately cause native biological diversity to decline.

As with any management action, reintroduction of fire should be considered carefully in light of clearly stated, measurable goals and objectives. Historic and prehistoric effects of fires serve as poor analogs for present (and near-future) effects, and pre-settlement fire regimes should not be used to justify contemporary management. Rather, reintroduction of fires should be evaluated in terms of expected benefits and costs to contemporary management of ecosystems.

The use of terms such as "health," "integrity," and "sustainability" as descriptors of ecosystems implies that managers or scientists can identify the state that is optimum for the ecosystem (vs. optimum for the production of specific resources) and that the preservation of this state is scientifically justifiable. These terms are not supported by empirical evidence or ecological theory, and should be abandoned in favor of other more explicit descriptors (Wicklum and Davies 1995). Appropriate goals and objectives should be identified on a site-specific basis and linked to ecosystem structures or functions that can be defined and quantified.

Pressing needs for the production of some resources and conservation of others indicate that management decisions cannot be postponed until complete scientific information is available on an issue. In

Figure 1.3 Purple loosestrife is a nonnative perennial plant that was introduced into North America in the early 1800s. By the 1930s, it was well established in wetlands and along drainage ditches in the east. Control of this and other exotic species requires consideration of the impact of potential control agents, as well as the nonnative species itself. Photo by Stephen DeStefano.

Figure 1.3 Purple loosestrife is a nonnative perennial plant that was introduced into North America in the early 1800s. By the 1930s, it was well established in wetlands and along drainage ditches in the east. Control of this and other exotic species requires consideration of the impact of potential control agents, as well as the nonnative species itself. Photo by Stephen DeStefano.

addition, management goals often change over time. These two considerations dictate the thoughtful implementation of management actions that do not constrain future management approaches and that are targeted at sustaining or increasing biodiversity (e.g., Burton et al. 1992). For example, widespread purposeful introduction of nonnative species illustrates a case of near-sighted management focused on the short-term solution of an acute problem, but which reduces future management options by potentially decreasing biodiversity and altering ecosystem structure and function (Abbott and McPherson 1999). Such narrowly focused management efforts are analogous to drilling a hole in the skull of a patient to relieve a severe headache (Figure 1.3).

Like all sciences, ecology is characterized by periodic dramatic changes in concepts. Progressive managers will want to be apprised of these paradigm shifts. For example, the Clementsian model of vegetation dynamics (Clements 1916; Dyksterhuis 1949) still serves as the basis for the classification and management of most public lands, despite the fact that the more appropriate state-and-transition model (Westoby et al. 1989) was adopted by ecologists over a decade ago. The delay in adopting the state-and-transition model by land managers probably stems, at least in part, from the absence of an analytical technique to quantify state conditions and transition probabilities (Joyce 1992). The state-and-transition model is described in Chapter 4.

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