scholarly journals Improving Estimates of Natural Resources Using Model-Based Estimators: Impacts of Sample Design, Estimation Technique, and Strengths of Association

2021 ◽  
Vol 13 (19) ◽  
pp. 3893
Author(s):  
John Hogland ◽  
David L. R. Affleck

Natural resource managers need accurate depictions of existing resources to make informed decisions. The classical approach to describing resources for a given area in a quantitative manner uses probabilistic sampling and design-based inference to estimate population parameters. While probabilistic designs are accepted as being necessary for design-based inference, many recent studies have adopted non-probabilistic designs that do not include elements of random selection or balance and have relied on models to justify inferences. While common, model-based inference alone assumes that a given model accurately depicts the relationship between response and predictors across all populations. Within complex systems, this assumption can be difficult to justify. Alternatively, models can be trained to a given population by adopting design-based principles such as balance and spread. Through simulation, we compare estimates of population totals and pixel-level values using linear and nonlinear model-based estimators for multiple sample designs that balance and spread sample units. The findings indicate that model-based estimators derived from samples spread and balanced across predictor variable space reduce the variability of population and unit-level estimators. Moreover, if samples achieve approximate balance over feature space, then model-based estimates of population totals approached simple expansion-based estimates of totals. Finally, in all comparisons made, improvements in estimation were achieved using model-based estimation over design-based estimation alone. Our simulations suggest that samples drawn from a probabilistic design, that are spread and balanced across predictor variable space, improve estimation accuracy.

2017 ◽  
Vol 1 (1) ◽  
pp. 1-16
Author(s):  
John Harner ◽  
Lee Cerveny ◽  
Rebecca Gronewold

Natural resource managers need up-to-date information about how people interact with public lands and the meanings these places hold for use in planning and decision-making. This case study explains the use of public participatory Geographic Information System (GIS) to generate and analyze spatial patterns of the uses and values people hold for the Browns Canyon National Monument in Colorado. Participants drew on maps and answered questions at both live community meetings and online sessions to develop a series of maps showing detailed responses to different types of resource uses and landscape values. Results can be disaggregated by interaction types, different meaningful values, respondent characteristics, seasonality, or frequency of visit. The study was a test for the Bureau of Land Management and US Forest Service, who jointly manage the monument as they prepare their land management plan. If the information generated is as helpful throughout the entire planning process as initial responses seem, this protocol could become a component of the Bureau’s planning tool kit.


2005 ◽  
Vol 156 (8) ◽  
pp. 264-268
Author(s):  
James J. Kennedy ◽  
Niels Elers Koch

The increasing diversity, complexity and dynamics of ecosystem values and uses over the last 50 years requires new ways for natural resource managers (foresters, wildlife biologists, etc.)to understand and relate to their professional roles and responsibilities in accommodating urban and rural ecosystem users, and managing the complimentary and conflicting interactions between them. Three stages in Western-world natural resources management are identified and analyzed, beginning with the (1) Traditional stage: natural resources first, foremost and forever, to (2) Transitional stage: natural resource management,for better or worse, involves people, to (3) Relationship stage: managing natural resources for valued people and ecosystem relationships. The impacts of these three perspectives on how natural resource managers view and respond to ecosystems,people and other life-forms is basic and can be profound.


<i>Abstract</i>.—Contemporary definitions of aquatic resource stewardship are a specific expression of ethical themes that humankind has wrestled with for millennia. The foundations for a stewardship ethic can be secular or spiritual. Other chapter contributors discuss a range of the secular foundations (e.g., fishing, boating); we discuss the implications of stewardship ethics rooted in religious traditions. Some fisheries professionals recognize religious–cultural influences on aquatic stewardship, such as those seen in Native American or Asian immigrant communities. But fisheries professionals have commonly ignored mainline Judeo-Christian faith traditions as an ethical basis for aquatic stewardship behavior, despite the fact that those traditions inform ethical development for large numbers of people in North America and that denominations within those traditions have increasingly engaged in stewardship-based environmental education and advocacy. The proposition that religious values often form the basis for a stewardship ethic presents several challenges for fisheries professionals striving to foster stewardship behavior. However, a basic understanding of these religious foundations could contribute to an improved practice of stewardship education, through outreach to a new constituency—faith communities. To illustrate this point, we briefly summarize some of the sources for stewardship found in the biblical corpus. We offer three examples of how Christian stewardship principles are manifest in aquatic stewardship programs delivered by faith communities. Models of partnership between natural resource managers and local faith communities are emerging across North America. In revisiting the ethical bases of stewardship and identifying new opportunities for stewardship education partnerships, we hope to demonstrate one more means by which fisheries professionals can bridge from stewardship education in principle to an effective practice of stewardship education.


<em>Abstract</em>—The North Fork Toutle River drains the northwest face of Mount St. Helens to the Cowlitz River, a major tributary of the Columbia River in southwestern Washington. In response to the 1980 eruption of Mount St. Helens, the U.S. Army Corps of Engineers constructed a sediment retention structure (SRS) in the North Fork Toutle River watershed to reduce the transport of fine sediment to the lower Cowlitz and Columbia River systems. The SRS was built without fish passage facilities and currently presents a significant barrier to migrating adult salmonids. To facilitate passage of coho salmon <em>Oncorhynchus kisutch </em>and steelhead <em>O. mykiss </em>to the upper watershed, a fish collection facility (FCF) was constructed 1.5 km downstream of the SRS, where fish are currently captured and transported to tributaries upstream of the SRS. We used radio telemetry to evaluate the movement of adult coho salmon and steelhead in the North Fork Toutle River in 2005 and 2006. A total of 40 coho and 42 steelhead were released from four different release sites in varied proportions. Release sites included the FCF, the SRS, and Alder Creek and Hoffstadt Creek, both North Fork Toutle River tributaries upstream of the SRS. Results from this research effort suggest that (1) unlike adult coho, adult steelhead are able to ascend the SRS spillway; (2) upstream adult coho and steelhead passage through the sediment plain is possible but may be flow-dependent; (3) adult coho and steelhead released in Alder Creek and Hoffstadt Creek tend to remain within their respective release tributary; and (4) postspawn steelhead emigration is limited. Future research is required to adequately address factors that influence movement of adult coho and steelhead in the upper North Fork Toutle River. The information resulting from this collaborative effort is enabling natural resource managers to determine whether the SRS spillway is a barrier to anadromous fish, to refine existing trap and haul operations, or, if appropriate, to consider modifying the spillway to enable volitional passage by upstream-migrating fish.


Author(s):  
Sherri L. Johnson

The influence of the Long-Term Ecological Research (LTER) program on my science has been to broaden my scope through exposure to long-term research and to encourage me to explore major questions across biomes. Communication and outreach with natural resource managers and policy makers has given me insight into translation of science and shaped my research. Through my experiences in the LTER program, I began collaborations with stream ecologists and biogeochemists across sites, which expanded into a high-profile research project that spanned several decades. I encourage scientists to work at LTER sites because they are supportive science communities with a wealth of information to share. Currently, I am a co–principal investigator at the H. J. Andrews Experimental Forest LTER project (AND) in Oregon and have been involved with LTER sites most of my professional life. In 1990, I began graduate research on freshwater shrimp responses to a hurricane at the Luquillo LTER site (LUQ) with Alan Covich, my PhD advisor at the University of Oklahoma. My involvement with LTER research expanded during my postdoctoral fellowship. Through the LTER All Scientists Meetings, I met Julia Jones and other researchers from AND. With their encouragement, I received a National Science Foundation (NSF) Postdoctoral Fellowship Grant in 1996 to examine stream temperature dynamics at AND. After several years at Oregon State University, I was hired by the US Forest Service (USFS) Pacific Northwest Research Station in 2001 as a USFS scientist for AND and became a co–principal investigator in 2002. I have had the benefit of being mentored for multiple years by Fred Swanson and have gradually assumed lead USFS responsibilities for AND. As a stream ecologist, I have studied basic questions and applied issues involving water quality, water quantity, and stream food webs, primarily in forested streams. My research at the LUQ site has examined responses of fresh water shrimp to disturbances and their role in ecosystem dynamics. At AND, my research exploring patterns and controls of stream temperature began as a theoretical landscape-scale question and expanded to examination of temperature responses to flow paths, calculations of heat budgets, and policy implications of forest management (Johnson and Jones 2000; Johnson 2004).


2011 ◽  
Vol 45 (1) ◽  
pp. 85-97 ◽  
Author(s):  
Neal R. Pettigrew ◽  
C. Patrick Fikes ◽  
M. Kate Beard

AbstractThe Northeastern Regional Association of Coastal Ocean Observing Systems (NERACOOS), which began in 2008, includes the University of Maine’s comprehensive data buoy array in the Gulf of Maine (GoM). The University of Maine buoy system started in 2001 as part of the Gulf of Maine Ocean Observing System (GoMOOS). The buoys provide a wide variety of oceanographic and marine meteorological data in real time to scientists, environmentalists, the National Weather Service, the U.S. Coast Guard and Canadian Coast Guard, educators, regional natural resource managers, the GoM fishing and maritime industries, and the general public. The GoM observing system is presently undergoing a redesign of the buoy control system to enhance remote access and reduce operational costs. The enhancements will allow remote trouble-shooting and reprogramming of the buoys and subsurface sensors. The system will also accommodate sensors from other research groups and allow them post-deployment control without assistance from our buoy group.Over the near-decade of operation, the system has revealed marked seasonal and interannual variability of the circulation and physical properties of the GoM. In the fall of 2004 to spring of 2005, Doppler currents measured an outflow of deep salty slope waters that suggest a regime shift in the inflow and outflow of transports through the Northeast Channel. During the same period, a salinity anomaly event lowered salinity throughout the GoM by roughly 2 psu by the winter of 2005. In following years, the previously unusual slope outflow and reduced salinity have often reoccurred.


2013 ◽  
Vol 2013 ◽  
pp. 1-6
Author(s):  
Zhi-Chao Sha ◽  
Zhang-Meng Liu ◽  
Zhi-Tao Huang ◽  
Yi-Yu Zhou

This paper addresses the problem of direction-of-arrival (DOA) estimation of coherent signals in the presence of unknown mutual coupling, and an autoregression (AR) model-based method is proposed. The effects of mutual coupling can be eliminated by the inherent mechanism of the proposed algorithm, so the DOAs can be accurately estimated without any calibration sources. After the mixing matrix is estimated by independent component analysis (ICA), several parameter equations are established upon the mixing matrix. Finally, all DOAs of coherent signals are estimated by solving these equations. Compared with traditional methods, the proposed method has higher angle resolution and estimation accuracy. Simulation results demonstrate the effectiveness of the algorithm.


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