Changes in phosphorus nutrition of sugar maple along a topographic gradient in the Quebec Appalachians

Abstract

In a typical sugar maple (Acersaccharum Marsh.) stand in the Quebec Appalachians, foliar phosphorus concentrations increased from the bottom to the top of the hill, while the humus form varied from a mull to a mor along the same slope sequence. Although limited, these observations within one stand presumably subjected to the same anthropogenic stresses, including acid loading, are consistent with those obtained on a regional scale by comparing the phosphorus nutrition of sugar maple stands growing on soils with contrasting humus forms. They support the observation that under the conditions prevailing in the Quebec Appalachians, phosphorus nutrition is affected mainly in stands growing on soils with a moderately acid mull humus. As foliar phosphorus may vary with variations in the humus form over short distances, corrective measures require planning for limited, well-defined areas.