Phenotypic plasticity and biomass allocation pattern in three Dryopteris (Dryopteridaceae) species on an experimental light-availability gradient

摘要: We were interested in whether the contrasting regional distribution patterns of three congeneric, frequently co-occurring fern species (Dryopteris carthusiana, D. dilatata and expansa) could be explained by differential biomass allocation strategies different phenotypic plasticities to light availability. The morphology habitat preference these ferns are known very similar, but Estonia, their frequencies occurrence differ sharply––Dryopteris carthusiana is common, expansa grows scattered localities, rare. grew under levels illumination (100, 50, 25 10% full daylight) an experimental garden compare autecological responses shading. After one growing season there clear interspecific differences total plant accumulation––D. > dilatata––indicating possible competitive inferiority latter at young sporophyte stage. was least shade-tolerant, with decreasing sharply less than 50% illumination; most similar growth all levels. In relative patterns, notable among shares stored rhizomes. this share nearly constant independent conditions. allocated little into rhizome deep shade, able increase more twofold light. Dryopteris clearly shown morphologically plastic three. four traits––rhizome mass, frond:below-ground ratio, stipe length specific leaf area––its degree ontogenetic plasticity significantly higher that carthusiana. While general performance (biomass production) experiment coincided observed nature, results estimation somewhat surprising––it difficult explain inferior a (D. dilatata) through high morphological plasticity. Probably, rare either because certain climatic restrictions, or it presently expanding its phase invading Estonian understory communities.