Linking Forest Inventory and Analysis Ground Data to Maps: An Example for Nevada Pinyon-Juniper Forests

Abstract

Using data from the USDA Forest Service's Forest Inventory and Analysis (FIA) program, we developed a mapping tool for displaying statistical forestland information. To develop this technique, we used data from Nevada's pinyon–juniper dryland forests, a major component of Nevada's forest cover important for food and wood sources, wildlife cover, and carbon storage. Land managers must grapple with issues, such as the health of these forests, the explanation of their encroachment into grasslands and shrublands, and causes of pinyon mortality associated with drought and bark-beetle activity. Our methodology can assist managers by offering the potential to map FIA statistics, such as carbon, volume, and stand structure to local conditions. FIA plots were classified according to the basal area occupied by dominant species groups. Employing this classification, we modeled the probability of pinyon–juniper occurrence at stand scale in Nevada from FIA data, using readily available remote sensing and geographic information system variables. Then, using the model with a Nevada-specific classification rule, we produced a cover map for the state. Finally, we linked our model classification rule to FIA summary data to create a detailed statistical map of Nevada forest carbon distribution—a visual representation of FIA data on the landscape.