John Wesley Powell Center for Analysis and Synthesis


Powell Center working groups rarely are just one USGS Mission Area and are sorted into these areas by the groups themselves. Projects may be relevant to additional areas.

View All Working Groups

Filter Total Items: 35
Date published: October 18, 2013
Status: Active

Evidence for shifts in plant species diversity along N deposition gradients: a first synthesis for the United States

The impacts of nitrogen (N) deposition on plant diversity loss have been well documented across N deposition gradients in Europe, but much less so in the U.S. Published N fertilizer studies suggest losses will occur in the US, but many of these were done at levels of N input that were higher than modeled and measured N deposition, and higher than presumed N critical loads. The recent...

Contacts: Matthew Brooks
Date published: September 20, 2013
Status: Active

Animal Migration and Spatial Subsidies: Establishing a Framework for Conservation Markets

Migratory species may provide more ecosystem goods and services to humans in certain parts of their range than others. These areas may or may not coincide with the locations of habitat on which the species is most dependent for its continued population viability. This situation can present significant policy challenges, as locations that most support a given species may be in effect...

Date published: September 20, 2013
Status: Active

Developing the next generation of USGS resource assessments

Resource assessments constitute a key part of the USGS mission, and represent a crucial contribution toward Department of the Interior (DOI) and broader Federal objectives. Current USGS energy and mineral assessment methods evaluate total technically recoverable resources (energy) or economically exploitable materials (minerals); the fiscal year 2010 budget for this work is $82M. To help...

Date published: September 19, 2013
Status: Active

Characterizing a link in the terrestrial carbon cycle: a global overview of individual tree mass growth

Forests sequester the majority of the terrestrial biosphere’s carbon and are key components of the global carbon cycle, potentially contributing substantial feedbacks to ongoing climatic changes. It is therefore remarkable that no consensus yet exists about the fundamental nature of tree mass growth (and thus carbon sequestration rate). Specifically, does tree mass growth rate increase,...

Date published: August 6, 2012
Status: Active

Next Generation of Ecological Indicators: Defining Which Microbial Properties Matter Most to Ecosystem Function and How to Measure Them

While it is widely recognized that microorganisms are intimately linked with every biogeochemical cycle in all ecosystems, it is not clear how and when microbial dynamics constrain ecosystem processes. As a result, it is know clear how to apply the value of increasingly detailed characterization of microbial properties to our understanding of ecosystem ecology. Several recent papers have...

Date published: June 7, 2012
Status: Active

Climate change and ecohydrology in temperate dryland ecosystems: a global assessment

Water cycling and availability exert dominant control over ecological processes and the sustainability of ecosystem services in water - limited ecosystems. Consequently, dryland ecosystems have the potential to be dramatically impacted by hydrologic alterations emerging from global change, notably increasing temperature and altered precipitation patterns. In addition, the possibility of...

Date published: June 6, 2012
Status: Active

Distribution of Fibrous Erionite in the United States and Implications For Human Health

Fibrous erionite, a zeolite mineral, has been designated as a human carcinogen by the World Health Organization and is believed to be the cause of extraordinarily high rates of malignant mesothelioma and other asbestos - related diseases in several villages in Central Turkey. A recent study by the University of Hawaii in collaboration with the U. S. Environmental Protection Agency in Dunn...

Date published: June 1, 2012
Status: Active

System analysis of land use and climate effects on ecosystem services affecting C and N exchanges with the atmosphere and water cycles

Current land use practices have affected ecosystem structure and processes in ways that have degraded delivery of key ecosystem services controlling exchanges of carbon and nitrogen with the atmosphere and surface and groundwater systems. These impacts are observed in the emissions of greenhouse gases (GHG) and N pollution in our nation’s water systems and coastal areas. Improvements in...

Date published: April 2, 2012
Status: Active

Global Croplands and Their Water Use for Food Security in the Twenty-first Century

Global climate change is putting unprecedented pressure on global croplands and their water use, vital for ensuring future food security for the world's rapidly expanding human population. The end of the green green revolution (productivity per unit of land) era has meant declining global per capita agricultural production requiring immediate policy responses to safeguard food security amidst...

Date published: February 29, 2012
Status: Active

Integrating ecological forecasting methods to improve applications for natural resource management: An invasive species example

Projecting the effects of climate change on plant and animal species distributions and abundance is critical to successful long‐term conservation and restoration efforts. There have been significant recent advances made in the areas of: (1) climate forecasts; (2) habitat niche modeling; (3) mechanistic modeling; and (4) observation techniques and networks. However, projections of biological...

Date published: February 29, 2012
Status: Active

Circumpolar assessment of ecological mismatch between avian herbivores and plant phenology

The timing of breeding is constrained in Arctic ecosystems and small temporal differences in when individuals breed can have large effects on fitness. Arctic ecosystems are generally warming more rapidly than other ecosystems which, for migratory species, can cause an imbalance, or mismatch, between when they have evolved to breed versus when it is optimal to breed environmentally. Geese are...