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1.
Front Ecol Environ ; 18(10): 576-583, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33408590

RESUMO

Addressing unexpected events and uncertainty represents one of the grand challenges of the Anthropocene, yet ecosystem management is constrained by existing policy and laws that were not formulated to deal with today's accelerating rates of environmental change. In many cases, managing for simple regulatory standards has resulted in adverse outcomes, necessitating innovative approaches for dealing with complex social-ecological problems. We highlight a project in the US Great Plains where panarchy - a conceptual framework that emerged from resilience - was implemented at project onset to address the continued inability to halt large-scale transition from grass-to-tree dominance in central North America. We review how panarchy was applied, the initial outcomes and evidence for policy reform, and the opportunities and challenges for which it could serve as a useful model to contrast with traditional ecosystem management approaches.

2.
Ecol Lett ; 20(1): 19-32, 2017 01.
Artigo em Inglês | MEDLINE | ID: mdl-28000431

RESUMO

Research on early warning indicators has generally focused on assessing temporal transitions with limited application of these methods to detecting spatial regimes. Traditional spatial boundary detection procedures that result in ecoregion maps are typically based on ecological potential (i.e. potential vegetation), and often fail to account for ongoing changes due to stressors such as land use change and climate change and their effects on plant and animal communities. We use Fisher information, an information theory-based method, on both terrestrial and aquatic animal data (U.S. Breeding Bird Survey and marine zooplankton) to identify ecological boundaries, and compare our results to traditional early warning indicators, conventional ecoregion maps and multivariate analyses such as nMDS and cluster analysis. We successfully detected spatial regimes and transitions in both terrestrial and aquatic systems using Fisher information. Furthermore, Fisher information provided explicit spatial information about community change that is absent from other multivariate approaches. Our results suggest that defining spatial regimes based on animal communities may better reflect ecological reality than do traditional ecoregion maps, especially in our current era of rapid and unpredictable ecological change.


Assuntos
Distribuição Animal , Aves/fisiologia , Mudança Climática , Ecossistema , Zooplâncton/fisiologia , Animais
3.
Ecology ; 95(3): 654-67, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24804450

RESUMO

Ecological structures and processes occur at specific spatiotemporal scales, and interactions that occur across multiple scales mediate scale-specific (e.g., individual, community, local, or regional) responses to disturbance. Despite the importance of scale, explicitly incorporating a multi-scale perspective into research and management actions remains a challenge. The discontinuity hypothesis provides a fertile avenue for addressing this problem by linking measureable proxies to inherent scales of structure within ecosystems. Here we outline the conceptual framework underlying discontinuities and review the evidence supporting the discontinuity hypothesis in ecological systems. Next we explore the utility of this approach for understanding cross-scale patterns and the organization of ecosystems by describing recent advances for examining nonlinear responses to disturbance and phenomena such as extinctions, invasions, and resilience. To stimulate new research, we present methods for performing discontinuity analysis, detail outstanding knowledge gaps, and discuss potential approaches for addressing these gaps.


Assuntos
Ecossistema , Modelos Biológicos , Animais , Aves/anatomia & histologia , Aves/fisiologia , Tamanho Corporal , Peixes/anatomia & histologia , Peixes/fisiologia , Dinâmica Populacional , Fatores de Tempo
4.
Mol Ecol Resour ; 11(1): 219-22, 2011 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-21429127

RESUMO

This article documents the addition of 229 microsatellite marker loci to the Molecular Ecology Resources Database. Loci were developed for the following species: Acacia auriculiformis × Acacia mangium hybrid, Alabama argillacea, Anoplopoma fimbria, Aplochiton zebra, Brevicoryne brassicae, Bruguiera gymnorhiza, Bucorvus leadbeateri, Delphacodes detecta, Tumidagena minuta, Dictyostelium giganteum, Echinogammarus berilloni, Epimedium sagittatum, Fraxinus excelsior, Labeo chrysophekadion, Oncorhynchus clarki lewisi, Paratrechina longicornis, Phaeocystis antarctica, Pinus roxburghii and Potamilus capax. These loci were cross-tested on the following species: Acacia peregrinalis, Acacia crassicarpa, Bruguiera cylindrica, Delphacodes detecta, Tumidagena minuta, Dictyostelium macrocephalum, Dictyostelium discoideum, Dictyostelium purpureum, Dictyostelium mucoroides, Dictyostelium rosarium, Polysphondylium pallidum, Epimedium brevicornum, Epimedium koreanum, Epimedium pubescens, Epimedium wushanese and Fraxinus angustifolia.


Assuntos
Bases de Dados de Ácidos Nucleicos , Dictyostelium/genética , Epimedium/genética , Haptófitas/genética , Repetições de Microssatélites , Dados de Sequência Molecular
5.
PLoS One ; 5(3): e9835, 2010 Mar 23.
Artigo em Inglês | MEDLINE | ID: mdl-20360985

RESUMO

The shelled pteropod (sea butterfly) Limacina helicina is currently recognised as a species complex comprising two sub-species and at least five "forma". However, at the species level it is considered to be bipolar, occurring in both the Arctic and Antarctic oceans. Due to its aragonite shell and polar distribution L. helicina is particularly vulnerable to ocean acidification. As a key indicator of the acidification process, and a major component of polar ecosystems, L. helicina has become a focus for acidification research. New observations that taxonomic groups may respond quite differently to acidification prompted us to reassess the taxonomic status of this important species. We found a 33.56% (+/-0.09) difference in cytochrome c oxidase subunit I (COI) gene sequences between L. helicina collected from the Arctic and Antarctic oceans. This degree of separation is sufficient for ordinal level taxonomic separation in other organisms and provides strong evidence for the Arctic and Antarctic populations of L. helicina differing at least at the species level. Recent research has highlighted substantial physiological differences between the poles for another supposedly bipolar pteropod species, Clione limacina. Given the large genetic divergence between Arctic and Antarctic L. helicina populations shown here, similarly large physiological differences may exist between the poles for the L. helicina species group. Therefore, in addition to indicating that L. helicina is in fact not bipolar, our study demonstrates the need for acidification research to take into account the possibility that the L. helicina species group may not respond in the same way to ocean acidification in Arctic and Antarctic ecosystems.


Assuntos
Complexo IV da Cadeia de Transporte de Elétrons/genética , Gastrópodes/classificação , Gastrópodes/fisiologia , Animais , Regiões Antárticas , Regiões Árticas , Teorema de Bayes , Carbonato de Cálcio/química , Primers do DNA/genética , Ecossistema , Oceanos e Mares , Filogenia , Especificidade da Espécie
6.
Mutat Res ; 652(2): 175-9, 2008 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-18346932

RESUMO

In September of 1987, a radiotherapy unit containing 50.9 TBq of Cs(137)Cl was removed from an abandoned radiotherapy clinic. This unit was subsequently disassembled leading to the most serious radiological accident yet to occur in the Western hemisphere. This event provides an opportunity to assess the genetic effects of ionizing radiation. We surveyed genetic variation of 12 microsatellite loci in 10 families of exposed individuals and their offspring and also in non-exposed families from the same area of Goias state. We found an increase in the number of new alleles in the offspring of the exposed individuals. The mutation rate was found to be higher in the exposed families compared to the control group. These results indicated that exposure to ionizing radiation can be detected in offspring of exposed individuals and also suggest that the elevated microsatellite mutation rate can be attributed to radioactive exposure.


Assuntos
Filhos Adultos , Radioisótopos de Césio/efeitos adversos , Mutação em Linhagem Germinativa , Repetições de Microssatélites , Liberação Nociva de Radioativos , Feminino , Humanos , Masculino , Exposição Materna , Pais , Exposição Paterna , Radiação Ionizante , Cinza Radioativa
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