A review of chemical and physical properties as indicators of forest soil quality: challenges and opportunities

Foresters have always relied on a knowledge of chemical and physical properties of soils to assess capacity of sites to support productive forests. Recently, the need for assessing soil properties has expanded because of growing public interest in determining consequences of management practices on the quality of soil relative to sustainability of forest ecosystem functions in addition to plant productivity. The concept of soil quality includes assessment of soil properties and processes as they relate to ability of soil to function effectively as a component of a healthy ecosystem. Specific functions and subsequent values provided by forest ecosystems are variable and rely on numerous soil physical, chemical, and biological properties and processes, which can differ across spatial and temporal scales. Choice of a standard set of specific properties as indicators of soil quality can be complex and will vary among forest systems and management objectives. Indices of forest soil quality which incorporate soil chemical, physical, and biological properties will be most readily adopted if they are sensitive to management-induced changes, easily measured, relevant across sites or over time, inexpensive, closely linked to measurement of desired values, and adaptable for specific ecosystems. This paper traces development of the concept of soil quality, explores use of soil chemical and physical properties as determinants of forest soil quality, and presents challenges and opportunities for forest soil scientists to play a relevant role in assessment and advancement of sustainable forest management by developing the concept of soil quality as an indicator of sustainability.