Variation in Foliage Composition and Diameter Growth of Yellow Birch with Season, Soil, and Tree Size

Abstract

AbstractFoliage samples and diameter measurements were taken periodically from yellow birch (Betula alleghaniensis) trees on well‐drained Hermon and poorly drained Whitman soils. Foliar analyses were made to determine seasonal changes in composition, and differences between trees and soil series. Leaf weights increased with season and were higher on the Whitman. Leaf moisture trends reflected soil moisture regimes. Nutrient percentages decreased during early June. Thereafter N, P, S, and K percentages flucturated slightly until September, then decreased until abscission, while Mg fluctuated considerably and Ca increased steadily. Absolute amounts of all six elements increased during June. Nitrogen, P, S, and K varied slightly during summer and decreased prior to leaf yellowing. Total Mg reached peak values in August and then decreased while total Ca increased continually. Total P, K, and S was comparable on both soils. Total N, Ca, and Mg was higher on the Whitman. Greater diameter increments of study trees were also recorded on the Whitman soil. The total content expression provided more meaningful information than nutrient percentages. Specific periods of sampling birch foliage are given.