Environments Program

Filter Total Items: 38
Date published: August 30, 2017

Reconstructing Flow History From Riparian Tree Rings

Aquatic Systems Branch scientists analyze rings of riparian trees relating tree growth and establishment to historical flow. We then use the tree rings to reconstruct the flow in past centuries. Flow reconstructions discover the frequency and magnitude of past droughts and floods—information that is essential for management of rivers and water supplies. We also use downscaled climate...

Date published: January 30, 2017

Use of Structured Decision Making to Optimize Salt Marsh Management Decisions at Northeastern National Wildlife Refuges

The Challenge: The U.S. Fish and Wildlife Service (FWS) needs tools to inform decisions regarding the management and restoration of salt marsh ecosystems on northeastern National Wildlife Refuges. Previously, we developed a structured decision making (SDM) framework for optimizing refuge management decisions. This SDM framework served as the foundation for FWS to implement a consistent...

Date published: January 30, 2017

Recovery of Eelgrass (Zostera marina L.) in Casco Bay, Maine, Following Destruction by European Green Crabs

The Challenge: Eelgrass provides essential functions to the ecology and economy of Maine’s coastal zone. When over half the eelgrass in Casco Bay, Maine, disappeared between 2012 and 2013, USGS experimental evidence identified disturbance from invasive European green crabs as the leading cause. Loss of vegetation is expected to precipitate a range of impacts, including reduced fish and...

Date published: January 17, 2017

Ecological Drought in Riparian Ecosystems

Drought is killing riparian trees along many rivers in the western United States. The cause can be increasing temperature or decreasing precipitation, flow or water-table elevation. At multiple locations we are relating water availability to physiological measurements of tree survival and water stress, such as ring width, carbon stable isotope ratio and branch hydraulic conductivity. These...

Date published: December 20, 2016

Estimation of Density and Abundance of Biological Populations on National Parks and Wildlife Refuges Through Distance Sampling

The Challenge: Assessing the status and trends of populations of biological organisms is an important management goal and a recurrent theme in USGS research. Often, the most basic question of “how many are there?” remains elusive, thus making management decisions more difficult. This study continues a long-term commitment of technical support for the use of distance sampling for wildlife...

Date published: December 20, 2016

Forest Structure Resulting from ‘Wildlife Forestry Silviculture’

The Challenge: Management of bottomland forests using wildlife forestry silviculture is being undertaken to achieve desired forest conditions for priority silvicolous wildlife, such as Louisiana black bear, migratory birds, and resident game species. Wildlife forestry management results in forests that have more open canopies and increased understory vegetation yet exhibit heterogeneous...

Date published: December 20, 2016

Monitoring Birds in National Parks of the Gulf Coast Network

The Challenge: Avian monitoring within the Gulf Coast Network of the National Park Service is challenged to provide valid quantitative data on bird populations within park boundaries with limited financial input. Thus, citizen science (volunteer) bird monitoring has been proposed to achieve reliable estimates of bird populations and to assess the effects of habitat change and temporal dynamics...

Date published: December 20, 2016

Bats in Forests Managed for Wildlife

The Challenge: Within the Mississippi Alluvial Valley (MAV), forest managers may prescribe variable retention silvicultural treatments within bottomland hardwood forests on public lands to improve forest conditions (i.e., structural heterogeneity, species composition, and senescence) for priority wildlife species. This is referred to as wildlife-forestry silviculture. However, concerns have...

Date published: December 20, 2016

Sustainably Designed Trails: Recent Recreation Ecology Findings on Design Factors Affecting Soil Loss

The Challenge: Achieving conservation objectives in protected natural areas requires the ability to sustain visitation while avoiding or minimizing adverse environmental impacts. Trails are an essential infrastructure component that limits resource impacts by concentrating use on hardened treads designed and maintained to sustain traffic. This is particularly challenging when visitation is...

Contacts: Jeff Marion, Ph.D., Dr. Jeremy Wimpey, Dr. Chris Carr, Dr. Yu-Fai Leung
Date published: December 20, 2016

Assessing Recreational Impact to Cliff Habitats and Rare Plants

The Challenge: The Potomac River Gorge, managed by the National Park Service in Virginia and Maryland, is a highly accessible protected natural area bordered by the intensively developed Washington metro region. The Gorge is biologically rich, with more than 400 occurrences of over 200 rare species. Potomac Gorge receives exceptionally heavy visitation, with nearly two million visitors...

Contacts: Jeff Marion, Ph.D., Dr. Jeremy Wimpey, Dr. Chris Carr, Dr. Yu-Fai Leung
Date published: December 20, 2016

Research and Management of Informal (Visitor-Created) Trails in Protected Areas

The Challenge: The proliferation and degradation of visitor-created “informal” trails in protected areas can be a vexing management issue for land managers. Formal trail systems never provide access to all locations required by visitors seeking to engage in a variety of appropriate recreational activities. Traveling off-trail may be necessary to engage in activities such as nature study,...

Contacts: Jeff Marion, Ph.D., Dr. Jeremy Wimpey, Dr. Chris Carr, Dr. Yu-Fai Leung
Date published: December 19, 2016

Integrating Estuarine Water-Quality Data in Northeastern National Parks

The Challenge: Estuaries in northeastern states are severely threatened by the adverse impacts of nutrient over-enrichment. USGS led the development of a vital-signs protocol to monitor estuarine nutrient status in northeastern National Parks, and monitoring has been operational in coastal parks from Massachusetts to Virginia since 2006. Monitoring results must be synthesized and interpreted...