Fire Regimes, Demography and Climatic Sensitivities of Navajo Forestlands: Insights From the Past to Inform Tribal Forest Management

EPA Grant Number: F13F51318
Title: Fire Regimes, Demography and Climatic Sensitivities of Navajo Forestlands: Insights From the Past to Inform Tribal Forest Management
Investigators: Guiterman, Christopher H
Institution: University of Arizona
EPA Project Officer: Lee, Sonja
Project Period: August 25, 2014 through August 25, 2016
Project Amount: $84,000
RFA: STAR Graduate Fellowships (2013) RFA Text |  Recipients Lists
Research Category: Academic Fellowships , Fellowship - Ecology

Objective:

This research takes place in the Chuska Mountains of the Navajo Nation, in partnership with the Navajo Forestry Department (NFD). The project was designed to address research needs identified by the NFD concerning the challenges that climate change poses to forest management and best pathways toward increasing forest resilience. To this end, the research strives (1) to quantify historical patterns of fire regimes and forest structure prior to extensive land use that led to an interruption of the fire regime in the early 1800s in order to assess the interplay between people, climate variability and fire and (2) to quantify long-term forest productivity and sensitivities of tree growth to climate variability across three major forest types in order to identify and triage areas where climate change might have the most profound effects on forest growth and survival.

Approach:

Standard dendrochronological procedures will be implemented throughout the data collection and analysis portions of this research. Land-use histories will be derived from existing ethnographic and historical accounts of Navajo peoples, as well as from archaeological surveys within the study area. Reconstructing past spatiotemporal dynamics of fire events and tree recruitment will be accomplished by collecting fire scarred  trees and regeneration dates across a new network of combined fire history-demography sites in the Chuska Mountains. To quantify forest growth on a landscape-scale, work will be conducted alongside the Navajo Forestry Department to sample tree rings from their gridded network of Continuous Forest Inventory plots. Knowledge transfer will be done iteratively through face-to-face meetings and visits to the field, with the goal of assisting the foresters in designing science-based management practices in their next 10-year management plan, in which they will be addressing the vulnerabilities of their forests to climate change.

Expected Results:

The dendrochronological analyses will generate multi-centennial perspectives on fire, age structure and tree growth-climate relationships. The fire history reconstruction will provide valuable data on the timing, frequency and scale of fires during a time period (pre-1850s) when Navajo people and widespread fires coexisted on the landscape, much in the same way as they would now if ecological processes were restored to Navajo forestlands. Identifying the primary climate drivers of forest growth across the Chuska Mountains will aid the NFD in preparing for future climate change by targeting their management strategies to those sites and forest types most sensitive to shifts in temperature and precipitation. These data sets also will be used to address several scientific knowledge gaps that concern the spatiotemporal dynamics of grazing-induced interruption of a surface fire regime, successional and ecological trajectories of forests that have been without fire for 70 to 100 years longer than elsewhere in the region, and refined estimates of forest-level sensitivities to climate from representatively sampled forest stands, as opposed to sites targeted specifically for drought sensitivity and climate reconstruction.

Potential to Further Environmental/Human Health Protection

The Chuska Mountains are a vital landscape to the Navajo Nation because they supply local communities with critical ecosystem services such as a clean and sustainable supply of drinking water, stable and fertile soils and traditional forest uses. The Navajo Forestry Department is responsible for maintaining forest health and resiliency across this landscape, as well as another five million acres of forests and woodlands. Due to a paucity of prior research, data necessary to address Navajo concerns regarding future environmental change are limited. Recognizing these challenges, the NFD have identified the research presented here as vital to their management practices, and it will therefore directly benefit and help to protect the environmental and human health of local communities of the Navajo Nation.

Supplemental Keywords:

climate change, ecosystem services, tribal communities

Progress and Final Reports:

  • 2015
  • Final