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Nebraska Cooperative Fish and Wildlife Research Unit: Staff Publications

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Protected Areas As Social-Ecological Systems: Perspectives From Resilience And Social-Ecological Systems Theory, Graeme S. Cumming, Craig R. Allen Jan 2017

Protected Areas As Social-Ecological Systems: Perspectives From Resilience And Social-Ecological Systems Theory, Graeme S. Cumming, Craig R. Allen

Nebraska Cooperative Fish and Wildlife Research Unit: Staff Publications

Conservation biology and applied ecology increasingly recognize that natural resource management is both an outcome and a driver of social, economic, and ecological dynamics. Protected areas offer a fundamental approach to conserving ecosystems, but they are also social-ecological systems whose ecological management and sustainability are heavily influenced by people. This editorial, and the papers in the invited feature that it introduces, discuss three emerging themes in social-ecological systems approaches to understanding protected areas: (1) the resilience and sustainability of protected areas, including analyses of their internal dynamics, their effectiveness, and the resilience of the landscapes within which they occur; (2) …


Adaptive Management For Ecosystem Services, Hannah E. Birgé, Craig R. Allen, Ahjond S. Garmestani, Kevin L. Pope Jan 2016

Adaptive Management For Ecosystem Services, Hannah E. Birgé, Craig R. Allen, Ahjond S. Garmestani, Kevin L. Pope

Nebraska Cooperative Fish and Wildlife Research Unit: Staff Publications

Management of natural resources for the production of ecosystem services, which are vital for human well-being, is necessary even when there is uncertainty regarding system response to management action. This uncertainty is the result of incomplete controllability, complex internal feedbacks, and nonlinearity that often interferes with desired management outcomes, and insufficient understanding of nature and people. Adaptive management was developed to reduce such uncertainty. We present a framework for the application of adaptive management for ecosystem services that explicitly accounts for cross-scale tradeoffs in the production of ecosystem services. Our framework focuses on identifying key spatiotemporal scales (plot, patch, ecosystem, …


Variability In Population Abundance Is Associated With Thresholds Between Scaling Regimes, Donald Wardwell, Craig R. Allen Jan 2009

Variability In Population Abundance Is Associated With Thresholds Between Scaling Regimes, Donald Wardwell, Craig R. Allen

Nebraska Cooperative Fish and Wildlife Research Unit: Staff Publications

Discontinuous structure in landscapes may result in discontinuous, aggregated species bodymass patterns, reflecting the scales of structure available to animal communities within a landscape. The edges of these body-mass aggregations reflect transitions between available scales of landscape structure. Such transitions, or scale breaks, are theoretically associated with increased biological variability. We hypothesized that variability in population abundance is greater in animal species near the edge of bodymass aggregations than it is in species that are situated in the interior of body-mass aggregations. We tested this hypothesis by examining both temporal and spatial variability in the abundance of species in the …


A Test Of The Cross-Scale Resilience Model: Functional Richness In Mediterranean-Climate Ecosystems, Donald A. Wardwell, Craig R. Allen, Garry D. Peterson, Andrew J. Tyre Jan 2007

A Test Of The Cross-Scale Resilience Model: Functional Richness In Mediterranean-Climate Ecosystems, Donald A. Wardwell, Craig R. Allen, Garry D. Peterson, Andrew J. Tyre

Nebraska Cooperative Fish and Wildlife Research Unit: Staff Publications

Ecological resilience has been proposed to be generated, in part, in the discontinuous structure of complex systems. Environmental discontinuities are reflected in discontinuous, aggregated animal body mass distributions. Diversity of functional groups within body mass aggregations (scales) and redundancy of functional groups across body mass aggregations (scales) has been proposed to increase resilience. We evaluate that proposition by analyzing mammalian and avian communities of Mediterranean-climate ecosystems. We first determined that body mass distributions for each animal community were discontinuous. We then calculated the variance in richness of function across aggregations in each community, and compared observed values with distributions created …


Predictors Of Introduction Success In The South Florida Avifauna, Craig R. Allen Jan 2006

Predictors Of Introduction Success In The South Florida Avifauna, Craig R. Allen

Nebraska Cooperative Fish and Wildlife Research Unit: Staff Publications

Biological invasions are an increasing global challenge, for which single-species studies and analyses focused on testing single hypotheses of causation in isolation are unlikely to provide much additional insight. Species interact with other species to create communities, which derive from species interactions and from the interactions of species with the scale specific elements of the landscape that provide suitable habitat and exploitable resources. I used logistic regression analysis to sort among potential intrinsic, community and landscape variables that theoretically influence introduction success. I utilized the avian fauna of the Everglades of South Florida, and the variables body mass, distance to …


The Use Of Discontinuities And Functional Groups To Assess Relative Resilience In Complex Systems, Craig R. Allen, L. Gunderson, A. R. Johnson Jan 2005

The Use Of Discontinuities And Functional Groups To Assess Relative Resilience In Complex Systems, Craig R. Allen, L. Gunderson, A. R. Johnson

Nebraska Cooperative Fish and Wildlife Research Unit: Staff Publications

It is evident when the resilience of a system has been exceeded and the system qualitatively changed. However, it is not clear how to measure resilience in a system prior to the demonstration that the capacity for resilient response has been exceeded. We argue that self-organizing human and natural systems are structured by a relatively small set of processes operating across scales in time and space. These structuring processes should generate a discontinuous distribution of structures and frequencies, where discontinuities mark the transition from one scale to another. Resilience is not driven by the identity of elements of a system, …


Variability Between Scales: Predictors Of Nomadism In Birds Of An Australian Mediterraneanclimate Ecosystem, Craig R. Allen, Denis A. Saunders Jan 2002

Variability Between Scales: Predictors Of Nomadism In Birds Of An Australian Mediterraneanclimate Ecosystem, Craig R. Allen, Denis A. Saunders

Nebraska Cooperative Fish and Wildlife Research Unit: Staff Publications

Nomadism in animals is a response to resource distributions that are highly variable in time and space. Using the avian fauna of the Mediterranean-climate region of southcentral Australia, we tested a number of variables to determine if they predicted nomadism. These variables were species body mass, the distance in body mass terms to the edge of a body mass aggregation, and diet (for example, seeds, invertebrates, nectar, or plants). We utilized two different classifications of the avifauna that diverged in their definition of nomadic to build two different predictive models. Using both classifications, distance to the edge of a body …


The Spatial Distribution Of Diversity Between Disparate Taxa: Spatial Correspondence Between Mammals And Ants Across South Florida, Usa, Craig R. Allen, L. G. Pearlstine, D.P. Wojcik, W.M. Kitchens Jan 2001

The Spatial Distribution Of Diversity Between Disparate Taxa: Spatial Correspondence Between Mammals And Ants Across South Florida, Usa, Craig R. Allen, L. G. Pearlstine, D.P. Wojcik, W.M. Kitchens

Nebraska Cooperative Fish and Wildlife Research Unit: Staff Publications

Gap Analysis takes a proactive landscape-level approach to conserving native species by identifying nodes of high biological diversity. It uses vertebrate species richness as an index of overall biological diversity. However, it remains unknownwhether or not the spatial distribution of vertebrate diversity correspondswith the diversity of other taxa. We tested whether landscape-level diversity patterns corresponded between a vertebrate and an invertebrate taxon, mammals and ants, across the southern half of the Florida peninsula, USA. Composite digital maps with a 30-m spatial resolution were produced for each taxon. Spatial correspondence between the taxa was determined by normalizing and then subtracting the …


Back-Calculated Length-At-Age Estimates From Two Scale Radii, Keith L. Hurley, Kevin L. Pope, David W. Willis Jan 1997

Back-Calculated Length-At-Age Estimates From Two Scale Radii, Keith L. Hurley, Kevin L. Pope, David W. Willis

Nebraska Cooperative Fish and Wildlife Research Unit: Staff Publications

Variability in length-at-age estimates back-calculated from scales continues to be of concern to fishery scientists. Measurement transects used to back-calculate length at age have been recommended; however, specific scale and annuli radius measurements have not been evaluated for variability between different radii. Thus, the purpose of our study was to compare back-calculated length-at-age estimates determined from two different scale radii: one horizontally from the focus to the anterior-median edge and one diagonally from the focus to the anterior-lateral corner of the scale. No significant differences (P = 0.13 - 0.58 and P = 0.24 - 0.87) in backcalculated length-at-age estimates …