Photosynthesis, Growth and Competitive Ability of Some Coniferous Forest Mosses and the Influence of Herbicides and Heavy Metals (Cu, Zn)

摘要

The importance of morphological characteristics and environmental variables as controlling factors for photo- synthesis and growth of Dicranum polysetum, Pleurozium schreberi and Ptilium crista-castrensis were studied. The three mosses had maximum assimilation capacity in different segments of the shoot and the growth form determined to what degree the capacity could be utilized. CO sub 2 fixation was limited by nutrient supply and selectivity affected by the environmental variables. In situ growth in a certain habitat or during a certain season closely corresponded to the oscillation of the variables important for CO sub 2 fixation. Application of 2,4-D,MCPA,Triclopyr and Glyphosate to populations of Dicranum, Pleurozium and five co-existing species gave selective effects on assimilation and respiration depending on bryophyte and herbicide. Generally, Glyphosate had negative long-term effects on photosynthesis of coniferous mosses with the exception of Sphagnum squarrosum. MCPA, 2,4-D and Triclopyr immediately decreased CO sub 2 fixation to maximally 30% of the control (Pleurozium and Hylocomium splendens). After one month CO sub 2 assimilation increased. Effects of varying concentrations of 2,4-D, and Glyphosate were studied and the influence on growth discussed. Assimilation and respiration of Dicranum was negatively related to increasing content of Cu+Zn in the shoot. The effect was significant at. (ERA citation 08:006261)