Measuring Trends in Ecological Resources<sup>1</sup>

Dixon, Philip M.; Olsen, A.R.; Kahn, Bruce M.

doi:10.1890/1051-0761(1998)008[0225:mtier]2.0.co;2

Cited by 25 publications

(15 citation statements)

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“…Ecological monitoring programmes range from those that monitor many sites infrequently to those that monitor a few sentinel sites frequently (Dixon et al 1998, Hewitt and Thrush 2007). For example, the US Long Term Ecological Research Network monitors a few sentinel sites very intensively (<http://www.lternet.edu/>), whereas the North American Breeding Bird Survey has a wide spatial coverage of sites that are monitored less intensively (<http://www.pwrc.usgs.gov/BBS/>).…”

Section: Discussionmentioning

confidence: 99%

Monitoring temporal trends in spatially structured populations: how should sampling effort be allocated between space and time?

Rhodes¹,

Jonzén²

2011

Ecography

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Estimating temporal trends in spatially structured populations has a critical role to play in understanding regional changes in biological populations and developing management strategies. Designing effective monitoring programmes to estimate these trends requires important decisions to be made about how to allocate sampling effort among spatial replicates (i.e. number of sites) and temporal replicates (i.e. how often to survey) to minimise uncertainty in trend estimates. In particular, the optimal mix of spatial and temporal replicates is likely to depend upon the spatial and temporal correlations in population dynamics. Although there has been considerable interest in the ecological literature on understanding spatial and temporal correlations in species’ population dynamics, little attention has been paid to its consequences for monitoring design. We address this issue using model‐based survey design to identify the optimal allocation of sampling effort among spatial and temporal replicates for estimating population trends under different levels of spatial and temporal correlation. Based on linear trends, we show that how we should allocate sampling effort among spatial and temporal replicates depends crucially on the spatial and temporal correlations in population dynamics, environmental variation, observation error and the spatial variation in temporal trends. When spatial correlation is low and temporal correlation is high, the best option is likely to be to sample many sites infrequently, particularly when observation error and/or spatial variation in temporal trends are high. When spatial correlation is high and temporal correlation is low, the best option is likely to be to sample few sites frequently, particularly when observation error and/or spatial variation in temporal trends are low. When abundances are spatially independent, it is always preferable to maximise spatial replication. This provides important insights into how spatio‐temporal monitoring programmes should be designed to estimate temporal trends in spatially structured populations.

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Section: Discussionmentioning

confidence: 99%

Monitoring temporal trends in spatially structured populations: how should sampling effort be allocated between space and time?

Rhodes¹,

Jonzén²

2011

Ecography

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“…A key issue in the design of monitoring programmes to track the response of the system to new management actions is to identify ecosystem indicators that are sufficiently representative of the health of the river ecosystem, directly address ecological goals, and are sufficiently responsive to flow management to enable evaluation of the success of the programme on relatively short time frames (Dixon et al, 1998;Rogers and Biggs, 1999;Parrish et al, 2003). In assessing the efficacy of environmental flow management, scientists must explicitly address the temporal and spatial scale of the response indicator variables with respect to the influence of the flow conditions to be imposed.…”

Section: Description Of the Processmentioning

confidence: 99%

A collaborative and adaptive process for developing environmental flow recommendations

Richter

Warner

Meyer

et al. 2006

River Research & Apps

349

276

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Many river restoration projects are focusing on restoring environmental flow regimes to improve ecosystem health in rivers that have been developed for water supply, hydropower generation, flood control, navigation, and other purposes. In efforts to prevent future ecological damage, water supply planners in some parts of the world are beginning to address the water needs of river ecosystems proactively by reserving some portion of river flows for ecosystem support. These restorative and protective actions require development of scientifically credible estimates of environmental flow needs. This paper describes an adaptive, inter-disciplinary, science-based process for developing environmental flow recommendations. It has been designed for use in a variety of water management activities, including flow restoration projects, and can be tailored according to available time and resources for determining environmental flow needs. The five-step process includes: (1) an orientation meeting; (2) a literature review and summary of existing knowledge about flow-dependent biota and ecological processes of concern; (3) a workshop to develop ecological objectives and initial flow recommendations, and identify key information gaps; (4) implementation of the flow recommendations on a trial basis to test hypotheses and reduce uncertainties; and (5) monitoring system response and conducting further research as warranted. A range of recommended flows are developed for the low flows in each month, high flow pulses throughout the year, and floods with targeted inter-annual frequencies. We describe an application of this process to the Savannah River, in which the resultant flow recommendations were incorporated into a comprehensive river basin planning process conducted by the Corps of Engineers, and used to initiate the adaptive management of Thurmond Dam.

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“…The questions, goals, and objectives of a monitoring program determine which ecological indicators are used (Dixon et al 1998). Ecological indicators have been applied from the level of the gene (e.g., Rublee et al 2001) to the landscape (e.g., Lausch & Herzog 2002) (Table 2).…”

Section: Niemi Mcdonaldmentioning

confidence: 99%

Application of Ecological Indicators

Niemi¹,

McDonald

2004

Annu. Rev. Ecol. Evol. Syst.

672

344

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■ Abstract Ecological indicators have widespread appeal to scientists, environmental managers, and the general public. Indicators have long been used to detect changes in nature, but the scientific maturation in indicator development primarily has occurred in the past 40 years. Currently, indicators are mainly used to assess the condition of the environment, as early-warning signals of ecological problems, and as barometers for trends in ecological resources. Use of ecological indicators requires clearly stated objectives; the recognition of spatial and temporal scales; assessments of statistical variability, precision, and accuracy; linkages with specific stressors; and coupling with economic and social indicators. Legislatively mandated use of ecological indicators occurs in many countries worldwide and is included in international accords. As scientific advancements and innovation in the development and use of ecological indicators continue through applications of molecular biology, computer technology such as geographic information systems, data management such as bioinformatics, and remote sensing, our ability to apply ecological indicators to detect signals of environmental change will be substantially enhanced.

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Measuring Trends in Ecological Resources¹

Cited by 25 publications

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Monitoring temporal trends in spatially structured populations: how should sampling effort be allocated between space and time?

Monitoring temporal trends in spatially structured populations: how should sampling effort be allocated between space and time?

A collaborative and adaptive process for developing environmental flow recommendations

Application of Ecological Indicators

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Measuring Trends in Ecological Resources1

Cited by 25 publications

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Monitoring temporal trends in spatially structured populations: how should sampling effort be allocated between space and time?

Monitoring temporal trends in spatially structured populations: how should sampling effort be allocated between space and time?

A collaborative and adaptive process for developing environmental flow recommendations

Application of Ecological Indicators

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Measuring Trends in Ecological Resources¹