Reed F. Noss

A Regional Landscape Approach to Maintain Diversity

Land managers have traditionally assumed that achieving maximum local habitat diversity will favor diversity of wildlife. Recent trends in species composition in fragmented landscapes suggest, however, that a more comprehensive view is required for perpetuation of regional diversity. A regional network of preserves, with sensitive habitats insulated from human disturbance, might best perpetuate ecosystem integrity in the long term. (Accepted for publication 5 May 1983)

Nodes, networks, and MUMs: Preserving diversity at all scales

The present focus of practical conservation efforts is limited in scope. This narrowness results in an inability to evaluate and manage phenomena that operate at large spatiotemporal scales. Whereas real ecological phenomena function in a space-time mosaic across a full hierarchy of biological entities and processes, current conservation strategies address a limited spectrum of this complexity. Conservation typically is static (time-limited), concentrates on the habitat content rather than the landscape context of protected areas, evaluates relatively homogeneous communities instead of heterogeneous landscapes, and directs attention to particular species populations and/or the aggregate statistic of species diversity. Insufficient attention has been given to broad ecological patterns and processes and to the conservation of species in natural relative abundance patterns (native diversity).The authors present a conceptual scheme that evaluates not only habitat content within protected areas, but also the landscape context in which each preserve exists. Nodes of concentrated ecological value exist in each landscape at all levels in the biological hierarchy. Integration of these high-quality nodes into a functional network is possible through the establishment of a system of interconnected multiple-use modules (MUMs). The MUM network protects and buffers important ecological entities and phenomena, while encouraging movement of individuals, species, nutrients, energy, and even habitat patches across space and time. An example is presented for the southeastern USA (south Georgia-north Florida), that uses riparian and coastal corridors to interconnect existing protected areas. This scheme will facilitate reintroduction and preservation of wide-ranging species such as the Florida panther, and help reconcile species-level and ecosystem-level conservation approaches.

CARNIVORES AS FOCAL SPECIES FOR CONSERVATION PLANNING IN THE ROCKY MOUNTAIN REGION

Viability analysis of well-selected focal species can complement ecosystem-level conservation planning by revealing thresholds in habitat area and landscape connectivity. Mammalian carnivores are good candidates for focal species because their distributional patterns often strongly reflect regional-scale population processes. We incorporated focal species analysis of four carnivore species, fisher (Martes pennanti), lynx (Lynx canadensis), wolverine (Gulo gulo), and grizzly bear (Ursus arctos), into a regional conservation plan for the Rocky Mountains of the United States and Canada. We developed empirical habitat models for fisher, lynx, and wolverine based on a geographically extensive data set of trapping and sighting records. Predictor variables derived directly from satellite imagery were significantly correlated with carnivore distribution and allowed us to predict distribution in areas lacking detailed vegetation data. Although we lacked similar distributional data for grizzly bear, we predicted be...

From plant communities to landscapes in conservation inventories: A look at the nature conservancy (USA)

Abstract The Nature Conservancy (TNC—USA) has developed an efficient system for inventory and evaluation of ‘elements-of-diversity’. The major components of this system are a ‘fine filter’ for species inventory and a ‘coarse filter’ for community-type inventory. As in traditional vegetation science, community sampling and classification are restricted to relatively homogeneous stands and avoid edges, ecotones, and disturbed areas. TNC employs a habitat-based system of natural communities to complement plant community classification. This system is used to identify stands that cumulatively encompass the full range of variation within each defined natural community type. Ecological relationships among community-types in real landscapes, however, are not accounted for. This paper reviews some important ecological functions of heterogeneous landscapes, which are not necessarily protected by conservation strategies that focus on separate, homogeneous community-types. Recommendations to expand TNCs coarse filter to landscapes include: (1) Disturbance regime and regeneration patterns should be evaluated for each major community-type, and for each site representing a type or group of types; (2) Functional combinations of community-types and developmental stages (landscape mosaics) should be addressed in the TNC system; (3) Landscape context (e.g., surrounding habitat types and connectivity) for a site is as important as the habitat content (e.g., the rarity or quality of community-types present). Attention to landscape-level patterns and processes will be helful for evaluating large sites that are composed of many community-types, and in setting selection and stewardship priorities for sites for any size that are surrounded by dissimilar habitat.

Managing fire-prone forests in the western United States

The management of fire-prone forests is one of the most controversial natural resource issues in the US today, particularly in the west of the country. Although vegetation and wildlife in these forests are adapted to fire, the historical range of fire frequency and severity was huge. When fire regimes are altered by human activity, major effects on biodiversity and ecosystem function are unavoidable. We review the ecological science relevant to developing and implementing fire and fuel management policies for forests before, during, and after wildfires. Fire exclusion led to major deviations from historical variability in many dry, low-elevation forests, but not in other forests, such as those characterized by high severity fires recurring at intervals longer than the period of active fire exclusion. Restoration and management of fire-prone forests should be precautionary, allow or mimic natural fire regimes as much as possible, and generally avoid intensive practices such as post-fire logging and planting.

Policy-driven versus Evidence-based Conservation: A Review of Political Targets and Biological Needs

Abstract “How much is enough?” is a question that conservationists, scientists, and policymakers have struggled with for years in conservation planning. To answer this question, and to ensure the long-term protection of biodiversity, many have sought to establish quantitative targets or goals based on the percentage of area in a country or region that is conserved. In recent years, policy-driven targets have frequently been faulted for their lack of biological foundation. In this manuscript, we reviewed 159 articles reporting or proposing 222 conservation targets and assessed differences between policy-driven and evidence-based approaches. Our findings suggest that the average percentages of area recommended for evidence-based targets were nearly three times as high as those recommended in policy-driven approaches. Implementing a minimalist, policy-driven approach to conservation could result in unanticipated decreases in species numbers and increases in the number of endangered species.

CONSIDERATIONS FOR THE DEVELOPMENT OF A TERRESTRIAL INDEX OF ECOLOGICAL INTEGRITY

Abstract Ecological systems are composed of complex biological and physical components that are difficult to understand and to measure. However, effective management actions and policy decisions require information on the status, condition, and trends of ecosystems. Multiple levels of information are needed to make effective decisions and the ideal indicators for measuring ecosystem integrity will incorporate information from multiple dimensions of the ecosystem. A terrestrial index of ecological integrity would be a useful tool for ecosystem managers and decision makers. The ideal requirements of the terrestrial index of ecosystem integrity (TIEI) are that it be comprehensive and multi-scale, grounded in natural history, relevant and helpful, able to integrate concerns from aquatic and terrestrial ecology, and that it be flexible and measurable. The objective of this research is to investigate if an index, or indices, could be developed that would summarize the condition of ecosystems so that changes can be tracked over time and this information utilized as a tool to support environmental decision making.

Adaptive capacity and learning to learn as leverage for social–ecological resilience

Adaptive capacity is increasingly recognized as essential for maintaining the resilience of social–ecological systems and for coping with environmental change. Four main requirements enable societies to successfully adapt to change: (1) the will and intention to maintain social–ecological resilience, (2) knowledge about current problems and the desired direction of change, (3) proactive behavior, and (4) the capacity to change existing patterns of behavior. The adaptive capacity of societies can be greatly enhanced by fostering the adaptive capacity of their individual members. Considerable knowledge about how to foster the adaptability of individuals exists in the science of education and in cognitive and social psychology. Developing the ability to learn flexibly in a variety of ways, contexts, and circumstances is an important element of developing adaptive capacity. The widespread implementation of modern teaching approaches in the education sector could make a substantial contribution to building and...

USE OF POPULATION VIABILITY ANALYSIS AND RESERVE SELECTION ALGORITHMS IN REGIONAL CONSERVATION PLANS

Current reserve selection algorithms have difficulty evaluating connectivity and other factors necessary to conserve wide-ranging species in developing landscapes. Conversely, population viability analyses may incorporate detailed demographic data, but often lack sufficient spatial detail or are limited to too few taxa to be relevant to regional conservation plans. We developed a regional conservation plan for mammalian carnivores in the Rocky Mountain region using both a reserve selection algorithm (SITES) and a spatially explicit population model (PATCH). The spatially explicit population model informed reserve selection and network design by producing data on the locations of population sources, the degree of threat to those areas from landscape change, the existence of thresholds to population viability as the size of the reserve network increased, and the effect of linkage areas on population persistence. A 15% regional decline in carrying capacity for large carnivores was predicted within 25 years i...

Bolder Thinking for Conservation

SHOULD CONSERVATION TARGETS, such as the proportion of a region to be placed in protected areas, be socially acceptable from the start? Or should they be based unapologetically on the best available science and expert opinion, then address issues of practicality later? Such questions strike to the philosophical core of conservation. Ambitious targets are often considered radical and value laden, whereas modest targets are ostensibly more objective and reasonable. The personal values of experts are impossible to escape in either case. Conservation professionals of a biocentric bent might indeed err on the side of protecting too much. Anthropocentric bias, however, more commonly affects target setting. The pro-growth norms of global society foster timidity among conservation professionals, steering them toward conformity with the global economic agenda and away from acknowledging what is ultimately needed to sustain life on Earth.