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Geology topics

Charles van Riper

Publications and source records attributed to Charles van Riper.

At least 55 records · Page 3Linked to original sources
USGS2013

Conflation and aggregation of spatial data improve predictive models for species with limited habitats: a case of the threatened yellow-billed cuckoo in Arizona, USA

Riparian vegetation provides important wildlife habitat in the Southwestern United States, but limited distributions and spatial complexity often leads to inaccurate representation in maps used to guide conservation. We test the use of data conflation and aggregation on multiple vegetation/land-cover maps to improve the accuracy of habitat models for the threatened western yellow-billed cuckoo (Coccyzus americanus occidentalis). We used species observations (n = 479) from a state-wide survey to develop habitat models from 1) three vegetation/land-cover maps produced at different geographic scales ranging from state to national, and 2) new aggregate maps defined by the spatial agreement of cover types, which were defined as high (agreement = all data sets), moderate (agreement ≥ 2), and low (no agreement required). Model accuracies, predicted habitat locations, and total area of predicted habitat varied considerably, illustrating the effects of input data quality on habitat predictions and resulting potential impacts on conservation planning. Habitat models based on aggregated and conflated data were more accurate and had higher model sensitivity than original vegetation/land-cover, but this accuracy came at the cost of reduced geographic extent of predicted habitat. Using the highest performing models, we assessed cuckoo habitat preference and distribution in Arizona and found that major watersheds containing high-probably habitat are fragmented by a wide swath of low-probability habitat. Focus on riparian restoration in these areas could provide more breeding habitat for the threatened cuckoo, offset potential future habitat losses in adjacent watershed, and increase regional connectivity for other threatened vertebrates that also use riparian corridors.

Arizona↗
USGS2013

Understanding how social networking influences perceived satisfaction with conference experiences

Social networking is a key benefit derived from participation in conferences that bind the ties of a professional community. Building social networks can lead to satisfactory experiences while furthering participants' long- and short-term career goals. Although investigations of social networking can lend insight into how to effectively engage individuals and groups within a professional cohort, this area has been largely overlooked in past research. The present study investigates the relationship between social networking and satisfaction with the 10th Biennial Conference of Research on the Colorado Plateau using structural equation modelling. Results partially support the hypothesis that three dimensions of social networking – interpersonal connections, social cohesion, and secondary associations – positively contribute to the performance of various conference attributes identified in two focus group sessions. The theoretical and applied contributions of this paper shed light on the social systems formed within professional communities and resource allocation among service providers.

Annals of Leisure Research↗
USGS2013

Tamarisk in riparian woodlands: A bird’s eye view

This chapter presents a “bird's eye” view of tamarisk and examines some issues surrounding the management of tamarisk in riparian woodlands. The focus on birds is based on the fact that they are a relatively well-studied group that can provide important insights into the role of tamarisk in riparian ecosystems. Because the decline of native riparian habitat occurred concurrently with the spread of tamarisk, this invasive species has been portrayed as a key factor in the reduction of riparian breeding bird numbers. The chapter begins with an overview of the early perceptions and realities of why and how birds use tamarisk before turning to a discussion of the history of tamarisk control and its effects on birds. It then considers some of the changing perspectives about the management of tamarisk and riparian habitats in western North America.

Book chapter↗
USGS2013

Desert fires fueled by native annual forbs: effects of fire on communities of plants and birds in the lower Sonoran Desert of Arizona

In 2005, fire ignited by humans swept from Yuma Proving Grounds into Kofa National Wildlife Refuge, Arizona, burning ca. 9,255 ha of Wilderness Area. Fuels were predominantly the native forb Plantago ovata . Large fires at low elevations were rare in the 19th and 20th centuries, and fires fueled by native vegetation are undocumented in the southwestern deserts. We estimated the area damaged by fire using Moderate Resolution Imaging Spectroradiometer and Normalized Difference Vegetation Index, which are more accurate and reduce subjectivity of aerial surveys of perimeters of fires. Assemblages of upland and xeroriparian plants lost 91 and 81% of live cover, respectively, in fires. The trees Olneya tesota and Cercidium had high amounts of top-kill. King Valley was an important xeroriparian corridor for birds. Species richness of birds decreased significantly following the fire. Numbers of breeding birds were lower in burned areas of King Valley 3 years post-fire, compared to numbers in nearby but unburned Alamo Wash. Although birds function within a large geographic scale, the extent of this burn still influenced the relative abundance of local species of breeding birds. This suggests that breeding birds respond to conditions of localized burns and slow recovery of vegetation contributes to continued lower numbers of birds in the burned sites in King Valley.

Arizona↗
USGS2013

Challenge theme 1: Understanding and preserving ecological resources: Chapter 3 in United States-Mexican Borderlands: Facing tomorrow's challenges through USGS science

The notable biodiversity within the United States–Mexican border region is driven by the wide variety of natural landscapes in the area and its biologically unique transition zone of habitats for xeric, temperate, and subtropical species. Six diverse ecoregions cover the length of the border (fig. 3–1): California Coastal Sage, Chaparral, and Oak Woodlands; Sonoran Desert; Madrean Archipelago; Chihuahuan Desert; Southern Texas Plains; and Western Gulf Coastal Plain. The unique geology and many of the distinctive geographic features and climatic conditions that have given rise to the diverse populations of plants and animals found in the Borderlands also attract human populations. The number of people living in the Borderlands has increased dramatically over recent years, from about 7 million in 1980 to almost 12 million in 2003; the population is estimated to be more than 18 million by 2020 (Peach and Williams, 2003). The human population increase and associated change in land use have contributed to habitat fragmentation and habitat loss for native species, thus threatening their survival. Some ways in which humans negatively affect plants and animals in the Borderlands include dewatering of aquatic ecosystems, water pollution, introduction and spread of invasive species, outdoor lighting, military and border enforcement activity, and energy development and transmission.

United States-Mexico Borderlands↗
USGS2013

Trichinosis

Trichinosis, or trichinellosis, is one of the most widespread global parasitic diseases of humans and animals. This ancient disease is caused by the larval stage of parasitic roundworms (nematodes) in the genus Trichinella. Often called the “trichina worm,” this parasite is considered to be the king of the parasite community, because it has adapted to an extremely wide range of hosts including domestic animals, wildlife, and humans. Trichinella spiralis is the usual cause of the disease in humans, but humans and many other mammals, birds, and reptiles also can be infected with other species or strains of Trichinella. Regardless of climate and environments, a wide variety of hosts on most continents are infected. Trichinella is transmitted through the ingestion of infected meat, primarily through predation or cannibalism of raw meat, and this ensures survival of the parasite in a wide variety of hosts. Humans become infected only by eating improperly cooked meat that contains infective larvae. While most people have only mild symptoms after infection, when high numbers of larvae are ingested trichinosis can cause serious disease, as well as death. Although trichinosis has been historically associated with pork, it is now emerging as a more widespread food-borne zoonosis as the consumption of wild game meat increases.

Circular↗
USGS2013

Great gray owls ( Strix nebulosa ) in Yosemite National Park: on the importance of food, forest structure, and human disturbance

We studied great gray owls (Strix nebulosa Forster) in Yosemite National Park, California, measuring variables that could potentially influence patterns of occurrence and conservation of this stateendangered species. We found that owl presence was closely tied to habitat (red fir (Abies magnified A. Murray) and the abundance of meadows), prey, and snags across the landscape. We also found that indicators of human recreational activities negatively influenced owl distribution and habitat use. Great gray owls appear to prefer mid-elevation red fir forest with meadows that are drier and more productive in terms of small mammal populations. That these areas also have the highest human activity presents a paradox, both for individual owls and for the future conservation and management of this California endangered species. The extent to which human recreation in natural areas affects animal behavior, species distribution, and productivity is a growing issue in natural area management. We present information that will allow land managers to better understand how existing natural resources, coupled with human recreation, influence the distribution and habitat use of the great gray owl.

California↗
USGS2013

Mapping landscape phenology preference of yellow-billed cuckoo with AVHRR data

We mapped habitat for threatened Yellow-billed Cuckoo (Coccycus americanus occidentalis) in the State of Arizona using the temporal greenness dynamics of the landscape, or the landscape phenology. Landscape phenometrics were derived from Advanced Very High Resolution Radiometer (AVHRR) Normalized Difference Vegetation Index (NDVI) data for 1998 and 1999 by using Fourier harmonic analysis to analyze the waveform of the annual NDVI profile at each pixel. We modeled the spatial distribution of Yellow-billed Cuckoo habitat by coupling the field data of Cuckoo presence or absence and point-based samples of riparian and cottonwood-willow vegetation types with satellite phenometrics for 1998. Models were validated using field and satellite data collected in 1999. The results indicate that Yellow-billed Cuckoo occupy locations within their preferred habitat that exhibit peak greenness after the start of the summer monsoon and are greener and more dynamic than “average” habitat. Identification of preferred phenotypes within recognized habitat areas can be used to refine habitat models, inform predictions of habitat response to climate change, and suggest adaptation strategies.

Arizona↗
USGS2012

Evaluation of NDVI to assess avian abundance and richness along the upper San Pedro River

Remote-sensing models have become increasingly popular for identifying, characterizing, monitoring, and predicting avian habitat but have largely focused on single bird species. The Normalized Difference Vegetation Index (NDVI) has been shown to positively correlate with avian abundance and richness and has been successfully applied to southwestern riparian systems which are uniquely composed of narrow bands of vegetation in an otherwise dry landscape. Desert riparian ecosystems are important breeding and stopover sites for many bird species but have been degraded due to altered hydrology and land management practices. Here we investigated the use of NDVI, coupled with vegetation, to model the avian community structure along the San Pedro River, Arizona. We also investigated how vegetation and physical features measured locally compared to those data that can be gathered through remote-sensing. We found that NDVI has statistically significant relationships with both avian abundance and species richness, although is better applied at the individual species level. However, the amount of variation explained by even our best models was quite low, suggesting that NDVI habitat models may not presently be an accurate tool for extensive modeling of avian communities. We suggest additional studies in other watersheds to increase our understanding of these bird/NDVI relationships.

Arizona↗
USGS2012

The U.S. Geological Survey Ecosystem Science Strategy, 2012-2022 - Advancing discovery and application through collaboration

Ecosystem science is critical to making informed decisions about natural resources that can sustain our Nation’s economic and environmental well-being. Resource managers and policy-makers are faced with countless decisions each year at local, state, tribal, territorial, and national levels on issues as diverse as renewable and non-renewable energy development, agriculture, forestry, water supply, and resource allocations at the urban-rural interface. The urgency for sound decision-making is increasing dramatically as the world is being transformed at an unprecedented pace and in uncertain directions. Environmental changes are associated with natural hazards, greenhouse gas emissions, and increasing demands for water, land, food, energy, mineral, and living resources. At risk is the Nation’s environmental capital, the goods and services provided by resilient ecosystems that are vital to the health and well-being of human societies. Ecosystem science—the study of systems of organisms interacting with their environment and the consequences of natural and human-induced change on these systems—is necessary to inform decision-makers as they develop policies to adapt to these changes. This Ecosystems Science Strategy is built on a framework that includes basic and applied science. It highlights the critical roles that USGS scientists and partners can play in building scientific understanding and providing timely information to decision-makers. The strategy underscores the connection between scientific discoveries and the application of new knowledge. The strategy integrates ecosystem science and decision-making, producing new scientific outcomes to assist resource managers and providing public benefits. The USGS is uniquely positioned to play an important role in ecosystem science. With its wide range of expertise, the agency can bring holistic, cross-scale, interdisciplinary capabilities to the design and conduct of monitoring, research, and modeling and to new technologies for data collection, management, and visualization. Collectively, these capabilities can be used to reveal ecological patterns and processes, explain how and why ecosystems change, and forecast change over different spatial and temporal scales. USGS science can provide managers with options and decision-support tools to use resources sustainably. The USGS has long-standing, collaborative relationships with the DOI and other partners in the natural sciences, in both conducting science and its application. The USGS engages these partners in cooperative investigations that otherwise would lack the necessary support or be too expensive for a single bureau to conduct. The heart of this strategy is a framework and vision for USGS ecosystems science that focuses on five long-term goals, which are seen as interconnected and reinforcing components: • Improve understanding of ecosystem structure, function, and processes. The focus for this goal is an understanding of how ecosystems work, including the dynamics of species, their populations, interactions, and genetics, and how they change across spatial and temporal scales. • Advance understanding of how drivers influence ecosystem change. The challenges here are explaining the drivers of ecosystem change, their spatio-temporal patterns, their uncertainties and interactions, and their influence on ecosystem processes and dynamics. • Improve understanding of the services that ecosystems provide to society. Here the emphasis is on the measurement of environmental capital and ecosystem services, and the identification of sources and patterns of change in space and time. • Develop tools, technologies, and capacities to inform decision-making about ecosystems. This includes developing new technologies and approaches for conducting applications-oriented ecosystem science. A principal challenge will be how to quantify uncertainty and incorporate it in decision analysis. • Apply science to enhance strategies for management, conservation, and restoration of ecosystems. These challenges include development of novel approaches to monitoring, assessment, and restoration of ecosystems; new methods to address species of concern and communities at risk; and innovations in decision analysis and support to address imminent ecosystem changes or those that are underway. Closely integrated with the five goals are four strategic approaches that provide the path forward for the USGS Ecosystems Mission Area. These approaches cross-cut all of the goals and are seen as essential to the implementation of this strategy: • Assess information needs for ecosystem science through enhanced partnerships. Work with the DOI and other agencies and institutions to identify, design, and implement priority decision-driven ecological research. • Promote the use of interdisciplinary ecosystem science. Design and conduct interdisciplinary process-oriented research in ecosystem science. • Enhance modeling and forecasting. Build models to forecast ecosystem change, assess future management scenarios, and reduce uncertainties through an adaptive learning process. • Support decision-making. Use quantitative approaches to assess the vulnerabilities of ecosystems, habitats, and species, and evaluate strategies for adaptation, restoration, and sustainable management. Following the strategic approaches are a set of proposed actions that represent a sampling of specific activities that align with this strategy and that address the Nation’s most pressing environmental needs. The strategy emphasizes coordination of activities across the USGS mission areas pursuant to these goals. Ecosystem science is inherently interdisciplinary and requires a broad perspective that incorporates the biological and physical sciences, climate science, information technology, and scientific capacity in mission areas across the Bureau. With its emphasis on coordination, this strategy can provide a critical underpinning for integrated science efforts with scientists from multiple mission areas of the USGS working together. Of course, the USGS will continue to conduct both discipline-specific and interdisciplinary investigations, and both will continue to be vital parts of the ecosystem science portfolio. Finally, the strategy stresses the importance of coordination with other Federal agencies and organizations in the natural resources community. The USGS collaborates with resource agencies in the DOI and other organizations throughout the world to meet societal needs for species and ecosystem management. Working with these agencies and organizations, the USGS will play a key role over the next decade in advancing the scientific foundation for sustaining the natural resources that diverse, productive, resilient ecosystems provide.

Open-File Report↗
USGS2012

Using integrated research and interdisciplinary science: Potential benefits and challenges to managers of parks and protected areas

Our purpose in this paper is to build a case for utilizing interdisciplinary science to enhance the management of parks and protected areas. We suggest that interdisciplinary science is necessary for dealing with the complex issues of contemporary resource management, and that using the best available integrated scientific information be embraced and supported at all levels of agencies that manage parks and protected areas. It will take the commitment of park managers, scientists, and agency leaders to achieve the goal of implementing the results of interdisciplinary science into park management. Although such calls go back at least several decades, today interdisciplinary science is sporadically being promoted as necessary for supporting effective protected area management(e.g., Machlis et al. 1981; Kelleher and Kenchington 1991). Despite this history, rarely has "interdisciplinary science" been defined, its importance explained, or guidance provided on how to translate and then implement the associated research results into management actions (Tress et al. 2006; Margles et al. 2010). With the extremely complex issues that now confront protected areas (e.g., climate change influences, extinctions and loss of biodiversity, human and wildlife demographic changes, and unprecedented human population growth) information from more than one scientific discipline will need to be brought to bear in order to achieve sustained management solutions that resonate with stakeholders (Ostrom 2009). Although interdisciplinary science is not the solution to all problems, we argue that interdisciplinary research is an evolving and widely supported best practice. In the case of park and protected area management, interdisciplinary science is being driven by the increasing recognition of the complexity and interconnectedness of human and natural systems, and the notion that addressing many problems can be more rapidly advanced through interdisciplinary study and analysis.

The George Wright Forum↗
USGS2012

Integrated science and interdisciplinary research for parks and protected areas

This paper summarizes presentations and discussion that focused on integrated science and the use of interdisciplinary research during a panel session held at the George Wright Society Meeting in New Orleans, March 14, 2011. The panel brought together nationally recognized members from the social and biological scientific communities, along with decision-makers and managers of parks and protected areas. The goal of the panel was to spark a discussion among panel members and the audience on the benefits and challenges of utilizing interdisciplinary research and integrated science to answer complex questions at the international, national, regional, and local park levels. The key focus points for the panel presentations and subsequent discussion revolved around the following five questions: How do we define interdisciplinary research and integrated science? What are the benefits, drawbacks, and challenges of interdisciplinary research and integrated science? When should this type of science be used? What are the barriers to employing interdisciplinary research and integrated science, and how can those perceived barriers be overcome? What are some examples of situations where this type of science has worked for you? We will break this paper down into seven sections, each summarizing the results of the panel presentations and subsequent audience discussion: 1. How do we define integrated science and interdisciplinary research? 2. The need for integrated science. 3. The challenges of integrated science and interdisciplinary research. 4. The benefits of integrated science and interdisciplinary research. 5. Integrated science in protected area management. 6. Communicating integrated science. 7. Key components to improve scientific outcomes.

Conference Paper↗
USGS2012

Avian community responses to vegetation structure within chained and hand-cut pinyon-juniper woodlands on the Colorado Plateau

We investigated relationships between breeding birds and vegetation characteristics in fuels-reduction treatment areas within pinyon-juniper woodlands at locations over the Colorado Plateau. The goal of this study was to document differences in avian community responses to two types of pinyon-juniper fuels-reduction treatments (chained vs. hand-cut), relative to control sites. We selected 73 vegetation plots in southern Utah and northern Arizona, of which 33 had been previously thinned by handcutting or chaining, and 40 control plots in untreated pinyon-juniper woodlands. At the 73 locations we documented vegetation structure and counted birds within 3.1 ha circular plots during the 2005 and 2006 breeding seasons. We focused in particular on the effects of fuels-reduction treatments to 16 bird species that are considered pinyon-juniper obligates. We found that density of pinyon pines was the most important variable in predicting bird species richness in all treatments and at control sites. Abundance of Brewer&rsquo;s Sparrow (<i>Spizella breweri</i>) was negatively related to chained, but positively related to hand cut areas. Vesper Sparrow (<i>Poocetes graminius</i>) abundance was negatively related to both chaining and handcutting. Within 16 pinyon-juniper obligate bird species, abundance of five was positively related to pinyon-pine density, while two were positively related to juniper density. These responses, along with other bird-vegetation relationships influenced by treatment type, need to be considered by land managers when planning fuels reduction treatments in pinyon-juniper woodland habitat in the Colorado Plateau.

Arizona, Colorado, New Mexico, Utah↗
USGS2011

Biological dimensions of tern management-a case study of the least tern in Sonora, Mexico, and a comparative analysis of reproductive investment in terns

Least terns (Sternula antillarum) are threatened by rapid human development on the northern coast of Sonora, Mexico. Terns are bellwethers for changes along the world's coastlines, as their coastal breeding habitat is vulnerable to flooding and development. We conducted targeted ground and aerial surveys for least tern colonies along 160 kilometers of coast, and document our findings on colony sizes at nine sites over 3 years in the first portion of this report. Like many taxa, terns lay larger clutches at higher latitudes. In the second portion of this report, we evaluate least tern breeding lifespan, food availability, and nest predation as potential ecological reasons behind this differing clutch-size pattern. After correcting for phylogenetic relationships, we found that food availability, not breeding lifespan or nest predation rate, was related to reproductive investment across 46 species and populations of terns. We conclude that coastal development may have a greater impact on nesting terns in tropical regions as compared to temperate breeding locations, because global oceanic patterns of decreased food availability reduce reproductive investment in the tropics.

Open-File Report↗
USGS2011

Avian community responses to juniper woodland structure and thinning treatments on the Colorado Plateau

Federal land managers are increasingly implementing fuels-reduction treatments throughout the western United States with objectives of ecological restoration and fire hazard reduction in pinyon-juniper (Pinus spp.-Juniperus spp.) woodlands. The pinyon-juniper woodland ecosystem complex is highly variable across the western landscape, as is bird community composition. We investigated relations between breeding birds and vegetation characteristics in modified pinyon-juniper woodlands at three sites (BLM, USFS, NPS) on the Colorado Plateau. During the breeding seasons of 2005 and 2006, we surveyed birds and measured vegetation in 74 study plots. These plots were each 3.1 hectares (ha; 7.6 acres), located across the range of natural variation, with 41 control sites and 33 plots in areas previously thinned by hand-cutting or chaining. We found that relations of avian pinyon-juniper specialists and priority species to vegetation characteristics were generally in agreement with the findings of previous studies and known nesting and feeding habits of those birds. Relatively high density of pinyon pines was important to species richness and abundance in 6 of 14 species. Abundance of all species was related to treatment method, and we found no difference in bird communities at chaining and hand-cut sites. We also studied responses of breeding birds to mechanical reduction of pinyon-juniper woodlands scattered across sagebrush steppe in 11 control and 9 treatment plots at Grand Staircase-Escalante National Monument, Utah, in 2005 and 2006. We surveyed birds in 3.1-ha (7.6-acre) plots during the breeding season before and following treatment. Thinning in April 2006 removed a mean of 92 percent (standard error = 6.4 percent) of the live trees from treatment plots. Two of 14 species, Gray Vireo (Vireo vicinior) and Brown-headed Cowbird (Molothrus ater), were not detected after thinning. Shrub-nesting birds, including sagebrush specialist Brewer's Sparrow (Spizella breweri), increased in relative abundance in treatment areas compared to controls. However, some species may exhibit a time lag in response, and further changes in community composition and abundance could result. Our findings lend support to the concept that multiple small-scale fuels-reduction treatments, applied over the landscape, may provide the variety of successional stages needed to support a full assemblage of avian species in pinyon-juniper woodlands on the Colorado Plateau. Limiting scale and increasing precision of fuels-reduction projects in pinyon-juniper vegetation communities may maximize the benefits of management to both the pinyon-juniper and sagebrush steppe avian communities. We conclude that small-scale fuels-reduction treatments can benefit many bird species while reducing fire risk and restoring an ecological balance.

Open-File Report↗
USGS2011

An inventory and monitoring plan for a Sonoran Desert ecosystem; Barry M. Goldwater Range-West

Marine Corps Air Station Yuma manages the Barry M. Goldwater Range-West, which encompasses approximately 2,800 square kilometers of Sonoran Desert habitat in southwestern Arizona. The Barry M. Goldwater Range is a major U.S. military installation designed as an air combat training location for the U.S. Marine Corps and U.S. Air Force, but it also includes some of the most pristine desert habitat in the United States. In an effort to ensure the long-term viability of this unique natural resource, the U.S. Geological Survey (USGS) has developed an Integrated Natural Resources Management Plan and Inventory and Monitoring Plan to guide natural resource management of the Barry M. Goldwater Range-West. This Inventory and Monitoring Plan provides a framework for long-term ecosystem monitoring on Barry M. Goldwater Range-West lands by identifying existing and potential threats to ecosystem function, prioritizing resources for monitoring, and providing information and protocols necessary to initiate a long-term ecosystem monitoring program. The Inventory and Monitoring Plan and related protocols were developed through extensive review of existing Sonoran Desert monitoring programs and monitoring literature and through a 2-day workshop with resource managers, monitoring experts, and other stakeholders. The Barry M. Goldwater Range-West Inventory and Monitoring Plan stresses the importance of regional monitoring partnerships and protocol standardization for understanding landscape-scale ecosystem changes in the Sonoran Desert; information and protocols contained within the plan may also be of interest to land managers engaged in large-scale ecosystem monitoring and adaptive management of other arid regions.

Open-File Report↗