TNC Center for Science and Public Policy - Reports, Data, and Updates

Sacaton Riparian Grasslands: Mapping Distribution and Ecological Condition

2012-11-19T21:58:05+00:00

Riparian grasslands dominated by big sacaton (Sporobolus wrightii) once covered floodplains across the southwest, but have been reduced to some 5% of their historical extent. Sacaton stands that remain provide key resources for watershed function, wildlife, and livestock—yet may need special management to sustain these benefits. This report describes mapping methods and management recommendations that can be applied to riparian grasslands throughout the region. By examining sacaton grasslands in the Las Cienegas National Conservation Area, this project also refines methods for evaluating ecological condition, and provides managers at this site with detailed maps of both high-quality habitat and restoration needs.

San Pedro River Wet-Dry Maps

2012-09-20T23:49:13+00:00

The San Pedro River wet/dry mapping dataset is a community effort to track the river’s health by monitoring the persistence of surface water during the driest time of each year. It is created by recording the end points of every wet section of the San Pedro River during June each year. Maps depict the wet portion of the San Pedro River.

Policy Options for Water Management in the Verde Valley, Arizona

2011-08-29T20:55:40+00:00

Central Arizona’s Verde River is a natural resource that is critical to the regional economy, environmental sustainability, and quality of life. The river’s future is uncertain, however, as there are still unresolved issues over how we grow while sustaining a healthy river. This report examines possible futures for the Verde River within the Verde Valley and provides information for stakeholders and decision-makers on the river’s resources, economic value, and tools for promoting sustainable water management. The report also summarizes three water management case studies from around the western U.S. that characterize the range of water management options that communities have adopted.

Wet/Dry Mapping: Using Citizen Scientists to Monitor the Extent of Perennial Surface Flow

2011-02-16T20:49:52+00:00

Published in Environmental Management, this article describes a simple method for monitoring the flow status of interrupted perennial streams, with the example of a 12-year effort on the San Pedro River. We found that surface flow increased for parts of the river, apparently due to conservation actions, while other parts were stable or may have declined. The data allowed us to map areas with surface flow in every year, totaling 32% of the river length through the San Pedro Riparian National Conservation Area (SPRNCA). These maps show areas with high year-to-year variation in flow length, which indicate changes in local groundwater conditions and may provide early warning of ecological changes.

Wet/Dry Mapping Instructions and Data Forms

2011-02-15T18:12:02+00:00

Example wet/dry mapping instructions and data forms used for the San Pedro wet/dry mapping effort. For more information, see our wet/dry mapping page.

Managing Changing Landscapes in the Southwestern United States

2010-12-14T21:54:14+00:00

This regional assessment examines the impacts of temperature change from 1951-2006 on natural resources in Arizona, New Mexico, Colorado, and Utah. It documents that warming has already affected habitats, watersheds, and species in the Southwest, by influencing the timing of seasonal events or amplifying the impacts of natural disturbances such as wildfire and drought. The report concludes that to begin adapting to climate change, natural resource managers should reevaluate the effectiveness of current restoration tools, modify resource objectives, learn from climate-smart adaptive management and monitoring, and share information across boundaries.

Arizona Statewide Freshwater Assessment GIS Data Package

2010-12-08T17:17:50+00:00

Includes 4 GIS datasets mapped to 1:100,000 scale stream-based hydrography for Arizona, including 1) the habitat for 33 native fish species, 2) former and current perennial surface flow for Arizona’s rivers, 3) the distribution of threatened and endangered species (ESA) that require aquatic or riparian habitats, and 4) Wild and Scenic River designations. Updated Dec 2010.

Wastewater Effluent: Biological Impacts of Exposure and Treatment Processes to Reduce Risk

2010-11-11T05:34:58+00:00

The Nature Conservancy commissioned a scientific literature review on impacts to aquatic organisms from exposure to municipal wastewater effluent. The review also covers the effectiveness and costs of available treatment technology for reducing exposure. The review was prepared by Dr. David Quanrud of the University of Arizona and Dr. Catherine Propper of Northern Arizona University. The executive summary provides an overview of the report’s major findings, including the best practices identified in the scientific literature for treating effluent.

The First Five Years of the White Mountain Stewardship Project

2010-08-29T19:47:12+00:00

The White Mountains Stewardship Project on the Apache-Sitgreaves National Forest in Arizona was designed to reduce the impacts of wildfires on communities, improve wildlife habitat, and help stimulate employment in the wood products industry. A multi-party monitoring board was convened to design a program for evaluating project effectiveness. This report summarizes results from five years of data on economic, social, administrative, and ecological indicators and provides recommendations for improving program effectiveness moving forward.

Sustainable Water Management in the Southwestern United States: Reality or Rhetoric?

2010-07-20T19:55:26+00:00

Published in PLoS ONE, this study used four scenarios to explore the potential effects of alternative growth and water management strategies on river flows. Under the base population projection, we found that rivers in seven of the 18 study watersheds could be dewatered due to municipal demand. Our approach provides a low-cost method to identify where alternative water and growth management strategies may have the most impact, and demonstrates that such strategies can maintain a continued water supply for both people and the environment.