Woody tissue analysis using an element ratio technique (DRIS)

The Diagnosis and Recommendation Integrated System (DRIS) was used to describe the variation of 12 elements in woody tree tissue of balsam fir (Abies balsamea (L.) Mill.), sugar maple (Acer saccharum Marsh.), jack pine (Pinus banksiana Lamb.), red pine (Pinus resinosa Ait.), and aspen (Populus tremuloides Michx.) across Minnesota, Wisconsin, and Michigan, United States. DRIS indices of elemental balance for the growth decades 1956-1965 and 1966-1975 were compared with standards developed from the growth decade 1976-1985. The DRIS analysis indicated that older wood of most species was relatively depleted of N, P, K, S, Fe, Cu, and Al. In at least one of the five species, however, K, S, Cu, or Al was relatively more abundant in older than in younger wood. The older wood of all species was relatively enriched in Ca, Mg, Mn, B, and Zn. Sulfur in older wood became relatively more enriched from west to east across a gradient of wet sulfate deposition; the trend was strongest for hardwood species. These results support the potential use of DRIS for monitoring stoichiometry of tissue from woody increment cores as an indicator of environmental stresses such as air pollution.