Production ecology ofPhragmites communis 1. Relations of two ecotypes to the microclimate and nutrient conditions of habitat

The growth rate of stand biomass, the seasonal development of vertical stand structure and accumulation of mineral nutrients were compared in twoPhrogmites ecotypes; the stands occur in two different biotopes, littoral and limosal, situated in the littoral of the Opatovický fishpond in the South Bohemian fishpond basin. Microclimatological data including incoming global radiation were recorded in both biotopes during three growing seasons. The differences in morphological, chemical and production characteristics of the two reed ecotypes were in good relation with the edaphic, hydrochemical and microclimatological characteristics of their biotopes. These differences are reflected in a higher leaf area index, denser stand, higher production parameters and a higher efficiency in the conversion of solar energy in the limosal reed ecotype as compared with the littoral population. The differences in annual production and in energy conversion have not changed within seven growing seasons.