SOILS AS AN INDICATOR OF FOREST HEALTH: A GUIDE TO THE COLLECTION, ANALYSIS, AND INTERPRETATION OF SOIL INDICATOR DATA IN THE FOREST INVENTORY AND ANALYSIS PROGRAM (FIA)

Authors: O Neill, Katherine; AMACHER, MICHAEL - USDA FOREST SERVICE; PERRY, CHARLES - USDA FOREST SERVICE

Submitted to: Forest Service General Technical Reports
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/2/2004
Publication Date: 11/2/2005
Citation: O Neill, K.P., Amacher, M., Perry, C. 2005. Soils as an indicator of Forest health: A guide to the collection, analysis, and interpretation of soil indicator data in the Forest Inventory and Analysis program (FIA). Gen. Tech. Rep. NC-258. St. Paul, MN: U.S. Department of Agriculture, Forest Service, North Central Research Station. 53 p.

Interpretive Summary: The Forest Inventory and Analysis (FIA) and Forest Health Monitoring (FHM) programs of the USDA Forest Service have recently implemented a national soil monitoring program to address specific questions related to the conservation of soil and water resources. As the only repeated, systematic sampling of key indicators of soil quality in all forested regions of the United States, this program provides critical baseline information on the current status of the soil resource and the potential effects of natural and human disturbance on forest health and productivity. Integration of soil assessments within the larger framework of the national FIA program provides a mechanism for systematic monitoring of soil properties using nationally-standardized collection, preparation, and data distribution formats that are fully compatible with existing forest inventory and forest health data. The purpose of this report is to present an overview of the current stage of development of this soil monitoring program and to provide guidance to analysts, researchers, and managers interested in using FIA soil data to address questions related to conservation and sustainable forest management. The discussion is divided into sections addressing the three primary foci of the soil indicator: soil erosion, soil compaction, and soil physical and chemical properties. For each topic, detailed information is provided regarding the types of data collected by FIA, the monitoring questions that these measurements were designed to address, and the importance of these measurements to the assessment of forest health. Field and laboratory methods are described for each measured variable along with a discussion of the strengths and potential limitations of these approaches. Finally, this report provides examples of analytical techniques that may be used to interpret these variables and to link soil measurements to ancillary datasets and models.

Technical Abstract: The Montreal Process was formed in 1994 to develop an internationally agreed upon set of criteria and indicators for the conservation and sustainable management of temperate and boreal forests. In response to this effort, the Forest Inventory and Analysis (FIA) and Forest Health Monitoring (FHM) programs have implemented a national soil monitoring program to address specific questions related to: (1) the current and future status of soil resources and (2) the contribution of forest soils to the global carbon cycle. As the first and only nationally consistent effort to monitor forest soil quality in the United States, this program provides critical baseline information on the current status of the soil resource and the potential effects of natural and human disturbance on forest health and productivity. This report provides documentation on the types of data collected as part of the FIA soil indicator, the field and laboratory methods employed, and the rationale behind these data collection procedures. Particular emphasis is placed upon describing generalized approaches for analyzing and interpreting soil indicator variables and discussing the strengths and limitations of individual soil variables. The analytical techniques detailed within this report are not intended to be exhaustive. Details of specific analytical approaches will be provided in a series of subsequent publications. Rather, the purpose is to provide guidance to analysts and researchers on ways to incorporate soil indicator data into reports and research studies.