Objectives for Multiple-Species Conservation Planning

The Ecology Centre, School of Integrative Biology, University of Queensland, St Lucia, Queensland 4072, Australia.
Conservation Biology (Impact Factor: 4.17). 07/2006; 20(3):871-81. DOI: 10.1111/j.1523-1739.2006.00369.x
Source: PubMed


The first step in conservation planning is to identify objectives. Most stated objectives for conservation, such as to maximize biodiversity outcomes, are too vague to be useful within a decision-making framework. One way to clarify the issue is to define objectives in terms of the risk of extinction for multiple species. Although the assessment of extinction risk for single species is common, few researchers have formulated an objective function that combines the extinction risks of multiple species. We sought to translate the broad goal of maximizing the viability of species into explicit objectives for use in a decision-theoretic approach to conservation planning. We formulated several objective functions based on extinction risk across many species and illustrated the differences between these objectives with simple examples. Each objective function was the mathematical representation of an approach to conservation and emphasized different levels of threat. Our objectives included minimizing the joint probability of one or more extinctions, minimizing the expected number of extinctions, and minimizing the increase in risk of extinction from the best-case scenario. With objective functions based on joint probabilities of extinction across species, any correlations in extinction probabilities had to be known or the resultant decisions were potentially misleading. Additive objectives, such as the expected number of extinctions, did not produce the same anomalies. We demonstrated that the choice of objective function is central to the decision-making process because alternative objective functions can lead to a different ranking of management options. Therefore, decision makers need to think carefully in selecting and defining their conservation goals.
Resumen: La identificación de objetivos es el primer paso en la planificación de conservación. La mayoría de los objetivos de conservación, tal como maximizar la biodiversidad, son muy vagos para ser útiles en un marco de toma de decisiones. Una manera de clarificar el tema es la definición de objetivos en términos del riesgo de extinción de múltiples especies. Aunque la evaluación del riesgo de extinción de una especie individual es común, pocos investigadores han formulado una función de objetivos que combina los riesgos de extinción de múltiples especies. Tratamos de traducir el objetivo general de maximizar la viabilidad de especies en objetivos explícitos para ser usados en un método de decisión teórica de planificación de conservación. Formulamos diversas funciones de objetivos basados en el riesgo de extinción de muchas especies, e ilustramos las diferencias entre esos objetivos con ejemplos simples. Cada función de objetivo fue la representación matemática de un método de conservación y enfatizaba diferentes niveles de amenaza. Nuestros objetivos incluyeron la minimización de la probabilidad conjunta de una o más extinciones, la minimización del número esperado de extinciones y la minimización del incremento en el riesgo de extinción en el mejor escenario. Con las funciones de objetivos basadas en probabilidades conjuntas de extinción de las especies, cualquier correlación en las probabilidades de extinción debería ser conocida o las decisiones resultantes eran potencialmente erróneas. Objetivos aditivos, tal como el número esperado de extinciones, no produjeron las mismas anomalías. Demostramos que la elección de la función de objetivo es central en el proceso de toma de decisiones porque las funciones de objetivos alternativas pueden llevar a una diferente clasificación de las opciones de manejo. Por lo tanto, los tomadores de decisiones deben pensar la selección y definición de sus metas de conservación cuidadosamente.


Available from: Emily Nicholson
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    • "Or do managers also want to target species with rare or vulnerable habitats? Alternative choices will lead to different prioritizations of management actions (Nicholson and Possingham 2006). The traditional approach to systematic conservation planning for reserve selection often uses data on the distribution of species, i.e., species richness, to inform decisions. "
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    ABSTRACT: Conservation practitioners, faced with managing multiple threats to biodiversity and limited funding, must prioritize investment in different management actions. From an economic perspective, it is routine practice to invest where the highest rate of return is expected. This return-on-investment (ROI) thinking can also benefit species conservation, and researchers are developing sophisticated approaches to support decision-making for costeffective conservation. However, applied use of these approaches is limited. Managers may be wary of ‘‘black-box’’ algorithms or complex methods that are difficult to explain to funding agencies. As an alternative, we demonstrate the use of a basic ROI analysis for determining where to invest in cost-effective management to address threats to species. This method can be applied using basic geographic information system and spreadsheet calculations. We illustrate the approach in a management action prioritization for a biodiverse region of eastern Australia. We use ROI to prioritize management actions for two threats to a suite of threatened species: habitat degradation by cattle grazing, and predation by invasive red foxes (Vulpes vulpes). We show how decisions based on cost-effective threat management depend upon how expected benefits to species are defined and how benefits and costs co-vary. By considering a combination of species richness, restricted habitats, species vulnerability, and costs of management actions, small investments can result in greater expected benefit compared with management decisions that consider only species richness. Furthermore, a landscape management strategy that implements multiple actions is more efficient than managing only for one threat, or more traditional approaches that don’t consider ROI. Our approach provides transparent and logical decision support for prioritizing different actions intended to abate threats associated with multiple species; it is of use when managers need a justifiable and repeatable approach to investment.
    Ecological Applications 09/2014; 24(6):1357-1373. DOI:10.1890/13-0711.1 · 4.09 Impact Factor
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    • "Implicit in this management decision is that habitat characteristics may simultaneously, and perhaps negatively, influence non-target taxa, perhaps including other taxa of conservation concern. Therefore, to reduce conservation conflict it is important to consider critical habitat and extirpation risks for multiple species in management plans (Lambeck 1997; Nicholson & Possingham 2006). However, while potential conflicts involving the management of threatened taxa have been reported (Roemer & Wayne 2003; Livezey 2010), these typically involve direct manipulations of the taxa rather than habitat restoration efforts. "
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    ABSTRACT: Although examples are rare, conflicts between species of conservation concern can result from habitat restoration that modifies habitat to benefit a single taxon. A forest restoration program designed to enhance habitat for endangered red‐cockaded woodpeckers (Picoides borealis) may be reducing available habitat for the eastern spotted skunk (Spilogale putorius), a forest‐adapted sympatric species of conservation concern that occurs in the Ouachita National Forest, Arkansas, U.S.A. At small scales, eastern spotted skunks select early successional forest with structural diversity, whereas red‐cockaded woodpeckers prefer mature pine (Pinus spp.) habitat. We surveyed for eastern spotted skunks at 50 managed forest stands, modeled occupancy as a function of landscape‐level habitat factors to examine how features of restoration practices influenced occurrence, and compared known occupied forest stands to those where active red‐cockaded woodpecker nesting clusters were located. The most‐supported occupancy models contained forest stand age (negatively associated) and size (positively associated); suggesting eastern spotted skunks primarily occupy large patches of habitat with dense understory and overhead cover. Red‐cockaded woodpecker nesting clusters were located in smaller and older forest stands. These results suggest that increased overhead cover, which can reduce risk of avian predation, enhances occupancy by small forest carnivores such as eastern spotted skunks. Management activities that increase forest stand rotation length reduce the availability of young dense forest. The practice may enhance the value of habitat for red‐cockaded woodpeckers, but may reduce the occurrence of eastern spotted skunks. Implementing plans that consider critical habitat and extinction risks for multiple species may reduce such conservation conflict.
    Restoration Ecology 03/2013; 21(2). DOI:10.1111/j.1526-100X.2012.00880.x · 1.84 Impact Factor
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    • "As such, it can serve as an example of nature conservation and management of Mediterranean ecosystems in Israel and the region. Here, we demonstrate a stakeholder engagement process for identifying conservation objectives (sensu Nicholson and Possingham, 2006) and targets (sensu Sanderson, 2006), using realistic working definitions of benefits and costs. "
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