The effect of solar UV radiation on four plant species occurring in a coastal grassland vegetation in The Netherlands

Abstract

During the summer of 1992, growth and some physiological parameters of four native plant species occurring in a coastal grassland in The Netherlands, were studied after reduction of solar UV irradiance using different cut‐off filters. Biomass production, morphology and photosynthesis of all species tested were unaffected by the different treatments. Litter production of Plantago lanceolata was increased in the absence of the total UV waveband, indicating a possible role for this waveband in plant senescence. Depletion of the total UV waveband from sunlight resulted in alterations in biomass allocation in Calamagrostis epigeios and Urtica dioica while no changes were observed in P. Ianceolata and Verbascum thapsus. In C. epigeios an increase in the specific leaf area was observed, whereas in U. dioica root weight per total plant weight was decreased resulting in an increase in the shoot/root ratio. Both photosynthetic and UV‐absorbing pigment concentrations were altered by the different filter applications. When compared to control plants receiving full sunlight, depletion of UV‐B resulted in a significant increase in chlorophyll concentration in U. dioica leaves, this however did not affect photosynthetic rate. The presence of UV‐B radiation enhanced the UV‐absorbance of leaf extracts of all species except P. lanceolata. Optical characteristics of the leaves were also changed. Both the quantity (P. lanceolata and U. dioica) and the quality (all species) of radiation transmitted by the leaves was affected by the different treatments.