Grassland reports & data

Enduring a decade of drought: Patterns and drivers of vegetation change in a semi-arid grassland (September 2016)

This study used a long-term dataset to examine the impacts of drought on grassland conditions at Las Cienegas National Conservation Area in southeastern Arizona from 2004-2014. Changes included declines in perennial grass basal cover with patchy mortality, leaf litter increases, shrub declines and increases in non-native grass, Lehmann’s Lovegrass (Eragrostis lehmanniana). Grassland cover declined by 25-50% in years with low precipitation from January-June. Given that global climate models predict steep declines in spring rainfall, grassland managers could improve grassland resilience by monitoring rainfall and associated mortality across multiple months, including non-traditional seasons, and by establishing contingency plans for various types of drought. The dataset was developed through a partnership between The Nature Conservancy and Bureau of Land Management with monitoring assistance from stakeholders.

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Sustaining the Grassland Sea (November 2013)

Grasslands of the Sky Islands region once covered over 13 million acres in southeastern Arizona and adjacent portions of New Mexico, Sonora, and Chihuahua. Roughly two-thirds of these remain as intact or restorable grassland habitat that provide watershed services such as flood control and aquifer recharge across the region, and continue to support dozens of species of concern. This study merged grassland condition assessments, information on grassland species, and expert knowledge to prioritize grassland landscapes across the region.

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Sacaton Riparian Grasslands: Mapping Distribution and Ecological Condition (October 2012)

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.

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Grasses of Las Cienegas National Conservation Area (June 2009)

This user-friendly field guide can help people of all skill levels identify 50 native and exotic perennial grasses, plus several annual species. This guide grew out of citizen science involvement tracking grassland health at the Las Cienegas National Conservation Area in southeastern Arizona. Some species illustrated here occur across the West; others are local specialties.

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Historical Range of Variation for Potential Natural Vegetation Types of the Southwest (June 2007)

Descriptions of the Historical Range of Variation or Variability (HRV) characterize the change over time and space in the condition of the Southwest’s major vegetation types and the ecological processes that shape those types. HRVs enable land managers and the public to understand the drivers of change in our region’s major vegetation types.

Report on the Biological Planning Process for Livestock Management at Las Ciénegas (May 2006)

Jointly authored by BLM and TNC, this report summarizes the monitoring information used and decision-making process for the 2005-2006 grazing plan at Las Ciénegas National Conservation Area. The report details how BLM, with input from partners, advisory teams, and the grazing permittee, are using upland monitoring data and pasture reconnaissance to make grazing management decisions.

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State of the Las Ciénegas National Conservation Area, Part I (July 2005)

Summarizes work completed to assist the Bureau of Land Management in the development and implementation of a science-based adaptive management and monitoring program to evaluate progress toward objectives established in BLM’s Resource Management Plan. Includes 1) an analysis of data collected between 1995 and 2004 on the condition and trend of the NCA’s grasslands, 2) a review of monitoring protocols, and 3) an outline of the adaptive management process implemented by BLM in 2004/2005.

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Watershed Improvement Using Prescribed Burns as a Way to Restore Aquatic Habitat for Native Fish (May 2004)

Documents efforts by TNC and BLM to test a model that prescribed burns can be used to improve watershed conditions and aquatic habitat conditions. Study documents pre- and post-treatment results for the response of grasslands and for populations of the threatened Gila chub (Gila intermedia). Paper presented at USFS conference, May 11-15, 2004.

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Grasslands Assessment GIS Data (December 2004)

A GIS data set depicting the results of a two-year study to delineate grasslands and evaluate their ecological condition in Arizona, southwestern New Mexico, and northern Mexico. This study was completed with the assistance of resource professionals from U.S. and Mexico universities and public agencies.

An Ecological Assessment of the Bureau of Land Management’s Current Fire Management Practices (March 2004)

This study reviews BLM’s fire management plans for Arizona, assessing the accuracy, standardization, and ecological relevance of current Phase I fire management areas. This second report documenting the results of TNC’s Arizona Grassland Assessment also makes recommendations for revisions to BLM’s fire management areas based on fire ecology and other considerations.

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An Assessment of the Spatial Extent and Condition of Grasslands in AZ, NM, and Northern Mexico (January 2003)

This report is the first of two studies completed by TNC and partners to delineate the spatial extent and ecological condition of grasslands in central and southern Arizona, southwestern New Mexico, and northern Mexico. This report covers the 30-million acre Apache Highlands Ecoregion.

See also An Ecological Assessment of BLM’s Current Fire Management Practices and Arizona Grasslands Assessment GIS Data for related reports and data.

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