FOREST AND WOODLAND DYNAMIC SUPPORTING FOOD AND AGRICULTURE ON THE NAVAJO NATION.

The project builds on the previously funded TCRGP grant. Collaborators are Northern Arizona Univeristy (NAU School of Forestry funded under the McIntire-Stennis Cooperative Forestry Research Program) and the Dine College School of STEM. Specific objectives are to carry out research on key themes that simultaneously provide needed information supporting food and agriculture while also building capacity for faculty and staff to provide enhance research, educational, and outreach capabilities to the Navajo Nation. As we build upon previous research we will expand into research on the basis of agricultural production, soil and fungal (mycobial) communities, along with the food (pinyon nuts) and agricultural production (forage, wood fiber) related to forest ecosystems on the Navajo Nation. 1) Forest mycobiome response to management affecting forest ecosystem health. 2) Three responses to management affecting pinyon nut production. 3) Ecosystem response to climatic variation in the past and future.Research Hypothesis:H1: (a) Mycobiome richness and diversity will be negatively impacted initially by thinning treatment. (b) Mycobiome communities within the treated units will experience a higher rate of turnover with seasonal changes. (c) Distribution of ecological guilds will differ between the treated and control units, with more plant pathogenic genera being recovered from the treated units.H2: (a) Pinyon nut production is expected to increase with age and size of trees until breakage, decay, and senescence set in. (b) Production will vary among individuals and by years according to climate. (c) Thinning treatments will enhance tree diameter growth and crown volume, which should foster improved future crops. (d) Thinning treatments will enhance woodland resilience by reducing fuel hazards that support severe wildfire.H3: (a) Tree-ring analysis will show tight linkage between climatic drivers, especially winter precipitation, and tree growth. (b) Pinyon trees at lower, drier sites will have greater sensitivity to climatic variation than ponderosa trees at higher, wetter sites. (c) Simulation modeling will show declines in tree productivity associated with warming climate scenarios, but management intervention could reduce losses.