Seasonal Changes in the Structure of the Herb Layer of a Deciduous Woodland )

Abstract

Light climate inside the woodland and integrated soil temperature were measured at 2 sites inside a Stellario-Carpinetum periodically from late winter (February) to early summer (June). During that period the herb layer emerged and fully developed. At various times during this period the structure of the herb layer was sampled by means of stratified clipping. Vegetation height, above ground phytomass, leaf area index, leaf-stem-flower fractions, leaf area ratio and indices of sclerophylly and succulence were determined for the whole stand and for the most important species separately. While vegetation height, above ground phytomass, leaf area index, leaf size and the degree of succulence reach maximum values during spring and then decline, leaf area ratio steadily increases, and the degree of sclerophylly gradually declines as the light climate inside the woodland deteriorates. Not surprisingly, seasonal differences for the whole stand can be partly explained in terms of shifts in dominance from Allium ursinum to Lamium galeobdolon, which considerably differ from one another in their structural features.Vertical arrangement of phytomass, leaf area, and leaf-stem-flower fractions are as expected. The results are compared with findings reported in the literature and are discussed in terms of plant performance and plant strategies.